Dissertations / Theses: 'Seasonal Selection'

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PENG, SISI. "Evaluating Automatic Model Selection." Thesis, Uppsala universitet, Statistiska institutionen, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-154449.

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In this paper, we briefly describe the automatic model selection which is provided by Autometrics in the PcGive program. The modeler only needs to specify the initial model and the significance level at which to reduce the model. Then, the algorithm does the rest. The properties of Autometrics are discussed. We also explain its background concepts and try to see whether the model selected by the Autometrics can perform well. For a given data set, we use Autometrics to find a “new” model, and then compare the “new” model with a previously selected one by another modeler. It is an interesting issue to see whether Autometrics can also find models which fit better to the given data. As an illustration, we choose three examples. It is true that Autometrics is labor saving and always gives us a parsimonious model. It is really an invaluable instrument for social science. But, we still need more examples to strongly support the idea that Autometrics can find a model which fits the data better, just a few examples in this paper is far from enough.

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Peck, Riley D. "Seasonal Habitat Selection by Greater Sage Grouse in Strawberry Valley Utah." BYU ScholarsArchive, 2011. https://scholarsarchive.byu.edu/etd/3180.

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This study examined winter habitat use and nesting ecology of greater sage grouse (Centrocercus urophasianus) in Strawberry Valley (SV), Utah located in the north-central part of the state. We monitored sage grouse with the aid of radio telemetry throughout the year, but specifically used information from the winter and nesting periods for this study. Our study provided evidence that sage grouse show fidelity to nesting areas in subsequent years regardless of nest success. We found only 57% of our nests located within the 3 km distance from an active lek typically used to delineate critical nesting habitat. We suggest a more conservative distance of 10 km for our study area. Whenever possible, we urge consideration of nest-area fidelity in conservation planning across the range of greater sage grouse. We also evaluated winter-habitat selection at multiple spatial scales. Sage grouse in our study area selected gradual slopes with high amounts of sagebrush exposed above the snow. We produced a map that identified suitable winter habitat for sage grouse in our study area. This map highlighted core areas that should be conserved and will provide a basis for management decisions affecting Strawberry Valley, Utah.

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McGeachy, David N. C. "Population Distribution and Seasonal Resource Selection by Elk (Cervus elaphus) in Central Ontario." Thesis, Laurentian University of Sudbury, 2014. https://zone.biblio.laurentian.ca/dspace/handle/10219/2181.

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Understanding population structure and resource selection are essential for wildlife management and conservation. I assessed the population structure and resource selection of elk (Cervus elaphus) in central Ontario. I used fuzzy and hierarchical cluster analyses to elucidate elk population structure based on spatial data collected from 41 radio-collared elk. I assessed impacts of habitat quality on space use using the minimum convex polygon (MCP) and fixed kernel methods. I evaluated resource selection by elk in winter, spring, summer, and fall, from December 2011 to August 2013, using resource selection functions (RSF’s). I used a generalized linear mixed model (GLMM) to evaluate resource selection functions and used Akaike information criterion (AICc ) to select the best model of 20 candidate models constructed a priori. Models included parameters representing resources known to be important to elk: elevation, aspect, slope, distance to roads and water, and habitat. Both fuzzy and hard clustering indicated that elk in Central Ontario occur in a metapopulation that includes 5 subpopulations. The largest cluster consisted of a core group of 22 radio-collared elk located in Burwash with several satellite subpopulations spread along a 50km long north-south axis and a small subpopulation to the west located in Worthington. Survival rates among subpopulations were similar ranging from 0.71 to 0.83; however, anthropogenic causes of mortality were predominant only in the Burwash subpopulation. Space use and density of elk differed between core and satellite subpopulations. Resource selection by elk differed by time of day and season. In all seasons, elk selected open habitats at night and more forested areas during the day. Elk avoided areas close to roads in spring, but selected them in winter at night. Elk selected higher elevations in winter and for south facing slopes in spring and fall. Elk displayed strong crepuscular activity patterns in all seasons; however, movements were limited in winter. Understanding population structure is important in order to develop appropriate management plans. My results support the conclusion that population structure can be reliably assessed using spatial data. Resource selection is a dynamic process that changes with seasons, as well as animal activity across the diel period. Resource selection should include time of day in order to obtain a complete picture of resources important to a particular species and to support the conservation of habitats used for various animal activities.

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Hill, Gregory J. "Examining Movement and Habitat Selection of Everglades Fishes in Response to Seasonal Water levels." FIU Digital Commons, 2017. http://digitalcommons.fiu.edu/etd/3209.

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Fish distribution patterns and seasonal habitat use play a key role in the food web dynamics of aquatic ecosystems, including the Florida Everglades. In this study I examined the fine scale habitat shifts and movements of spotted sunfish, Lepomis punctatus across varying seasons and hydrologic conditions using in-situ field enclosures and Passive Integrated Transponder (PIT) systems. Data on fish use of three dominant Everglades marsh habitats and activity level were recorded continuously from January to August, 2015. Fish were more active and had the highest use of higher elevation habitats when water levels rose during an experimental reversal in mid-April. Fish activity was higher at increasing water levels relative to decreasing. Fish activity also varied with the rate of change, with the highest activity occurring during rapid increases in depth. Findings from this study provide insight on how fish response to changing water levels may affect foraging for wading birds, a key performance measure for Everglades restoration.

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Jordan, Katherine Mead. "Characterization of seasonal reproduction in Virginia Tech Selection Line, St. Croix, and Suffolk ewes." Diss., Virginia Tech, 2008. http://hdl.handle.net/10919/28663.

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This dissertation research contained three studies. The first two studies were conducted to investigate the ability of ewes to rebreed while lactating during seasonal anestrus. Breeds studied included the Virginia Tech Out-of-season (OOS) Line, which is a wool line genetically selected to lamb in the fall, and the St. Croix, a hair breed of tropical origin thought to be lowly seasonal. When January-lambing ewes were exposed to rams while lactating in April, significantly more OOS than St. Croix ewes were marked by rams in the first 21 d and total 39 d of ram exposure (58.3 vs. 8.7%, P = 0.0003 and 95.8 vs. 43.5%, P < 0.0001). Percentages of ewes diagnosed pregnant (53.2%) and percentages of ewes lambing (41.3%) were not different between breeds. When March-lambing OOS ewes were exposed to rams while lactating in May, 52.9% of ewes were marked though only 20% of ewes exposed to rams gave birth to viable lambs. Both OOS and St. Croix ewes appear to be well suited to accelerated production systems involving 7 to 8 mo lambing intervals. However, reduction of lambing intervals to 6 to 7 mo appeared to have detrimental effects on fetal survival in OOS ewes. In a third study, alterations in endocrine profiles associated with differing degrees of hypothalamic sensitivity to estradiol-negative feedback and changing daylength in OOS, St. Croix, and Suffolk ewes in the absence of rams were investigated for 1 yr. The results show for the first time that based on progesterone profiles from intact ewes, St. Croix ewes do not have shorter anestrous periods than ewes of wool breeds, as previously thought. Based on luteinizing hormone profiles from ovariectomized ewes treated with estradiol implants, the duration of luteinizing hormone inhibition was shorter in OOS than Suffolk ewes (68 vs. 170.2 d, P = 0.02), but was not different from that found in St. Croix ewes (124.8 d). Specific roles for thyroxine and prolactin in timing the breeding season could not be assigned. This study was the first known use of the ovariectomized, estradiol-implanted ewe model to compare degree of reproductive seasonality in different breeds.
Ph. D.

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Baigas, Phillip E. "Winter habitat selection, winter diet, and seasonal distribution mapping of moose (Alces alces shirasi) in southeastern Wyoming." Laramie, Wyo. : University of Wyoming, 2008. http://proquest.umi.com/pqdweb?did=1797714121&sid=1&Fmt=2&clientId=18949&RQT=309&VName=PQD.

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Ross, Monica Ann. "Seasonal and Diel Patterns of Manatee Habitat Use." Master's thesis, University of Central Florida, 2007. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/2209.

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State and Federal agencies have created sanctuaries and speed zones to help reduce manatee mortality while incorporating the recreational and commercial resource needs of these same habitats for humans. Specific habitat resources are considered necessary to increase manatee survivorship. We have only recently begun to address how manatees use some of these resources based on physiological or reproductive strategies. In this study, I quantified patterns of habitat use during seasonal and diel periods for different sex and reproductive manatee classes using data from a radio-telemetry study conducted by the Florida Fish and Wildlife Conservation Commission during 1991-1996. I used five environmental geographic data layers: bathymetry, distance to seagrass, distance to shoreline, distance to warm water refuge sites, and distance to fresh water sources, to discriminate seasonal and diel habitat use patterns for different manatee classes: males (M), females with calves (FWC), and females without calves (FNC). Mean occupancy values were calculated for environmental variable locations and seasonal, diel, and manatee class differences were tested using a Multi-Response Permutation Procedure (MRPP). Nonmetric Multidimensional Scaling (NMS) was used to visualize the ordination patterns of the manatee classes and to assess importance of correlated environmental variables. Significant differences in habitat use were noted between summer and winter based on distances to warm water, seagrass, and fresh water sources but similar habitat use patterns were exhibited within summer diel periods among manatee classes. All manatee classes appeared to have used a higher proportion of locations closer in proximity to seagrass at night than day in winter indicating a disproportionate difference in feeding bouts between diel periods. These differences may be attributed to adjusting feeding strategies to reduce thermoregulatory costs or to decrease human interactions. Differences in patterns were exhibited for the winter diel periods specifically for the FWC manatee classes during winter days. FWC had a higher proportion of locations within the warm water refuges during the day indicating a possible trade off situation between food consumption and thermal exposure. This study demonstrates coarse and fine scale patterns of variation in habitat use for manatees both seasonally and daily within winter. It also suggests that during winter months, manatees were not just utilizing their habitat but they appeared to have preferences and selection for certain habitat types. Recovery of a species is greatly enhanced when patterns of habitat use within the species' environment has been clearly defined. Understanding more specifically what types of habitats manatees choose might allow management to adjust strategies for protection of key habitats while encouraging further recovery of this species.
M.S.
Department of Biology
Sciences
Biology MS

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Wyness, William. "Home range use by Southern Ground-Hornbills (Bucorvus leadbeateri) - quantifying seasonal habitat selection and vegetation characteristics." Bachelor's thesis, University of Cape Town, 2011. http://hdl.handle.net/11427/25599.

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The habitat of an animal is extremely important as it provides that animal with the necessary resources for fulfilling its life-history requirements (Brennan & Block, 1993; Beyer et al. 2010). A habitat is defined as a region in environmental space which comprises of multiple abiotic and biotic variables influencing an animal's location (Krausman, 1999; Beyer et al. 2010). Animals tend to utilise discrete areas within a habitat, constituting part of their home range. Home range analysis helps to delineate the area used by an animal habitually and areas of concentrated use (Samuel et al. 1985; Seaman & Powell, 1996; Moorcroft et al. 1999; Mitchell, 2007; Rodgers & Kie, 2011). Patterns of differential use of space within an animal's home range are the result of competing demands and trade-offs. In this study, a kernel technique was used to determine the home range of four satellitetracked groups of Southern Ground-Hornbills Bucorvus leadbeateri in the Associated Private Nature Reserves (APNR) in the South African lowveld. Satellite data were analysed in ArcGIS® 9.3 to quantify habitat selectivity by groups of ground-hornbills at different times of the year to determine a) favoured habitat types, and b) the resolution with which they perceive their environment. Each of the I groups showed variation in the utilisation and extent of their home ranges on a seasonal basis. Home range sizes contracted towards the nest during the summer breeding season (December to March) and expanded during the dry season (April to September). Within the home range of one of the groups the physical characteristics of habitat types (i.e. vegetation types) were sampled at 250 random co-ordinates in order to assess whether habitat preference at the meso-scale can be explained by the physical attributes of that vegetation type. By profiling and quantifying the vegetation of areas in the home range that are used by Southern Ground-Hornbills to differing degrees, this information could be used as a proxy to facilitate re-introduction efforts, by providing a tool to identify optimal landscape configurations.

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Garner, Nathan Paul. "Seasonal movements, habitat selection, and food habits of black bears (Urus americanus) in Shenandoah National Park, Virginia." Thesis, Virginia Polytechnic Institute and State University, 1986. http://hdl.handle.net/10919/50059.

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The seasonal movements, food habits, and habitat selection of black bears (Ursus americanus) in Shenandoah National Park, Virginia were studied from May 1982 to April 1985. A total of 47 collared bears, including 25 adult females, 17 adult males, and 5 subadult males < 3.5 years old, was located 3973 times during the study. Adult males had larger (P<0.001) home ranges (100% X=195 km², 95% X=116 km²) than adult females (100% X=38 km², 95% X=22 km²). Subadult males had larger (P<0.10) home ranges (100% X=542 km², 95% X=289 km²) than adult males and females. Extensive home range overlap occurred among each sex and age group. At least three subadult males dispersed from the Park during the study. Female bears with cubs were less mobile than solitary females during the spring. Fall cubs were large and did not restrict females' movements. Large fall home ranges for females were related to the scattered supply of acorns relative to the concentrated sources of soft mast used in the summer. Two females with cubs and 2 subadult males remained active during the winter months. Adult and subadult males generally had less stable home ranges than adult females. Female bears displayed infidelity to given areas during the fall from year-to-year due to variation in the distribution of hard mast (acorns). Male bears made long excursions onto the Piedmont Plateau east of the Park mainly during the spring and early fall. Females were not exposed to as much human induced mortality as males because they were located within the Park 17% more frequently than males. Males avoided fire roads (P<0.001), light duty roads (P<0.001), and primary roads (P<0.01) year around. Female bears preferred fire roads during summer (P< 0.001) and early fall (P<0.01) and avoided heavier traveled roads such as light duty roads (P<0.001) and primary roads (P<0.001) year around. Both male and female bears preferred foot trails for travel (P<0.05). Bears rarely came within 100 meters of campgrounds, picnic areas, and other human disturbance areas within the Park. Both sexes used low (P<0.10) elevations during the summer and high (P<0.10) elevations during early and late fall. Bears showed the greatest use of small rivers and streams during the driest months of summer. Geographic land forms of specific aspects, contours, and varying steepness were used differently by male and female bears. Twelve stomachs and 854 scats were analyzed for food content. Forbs, graminoids, squawroot (Conopholis americana), corn, and the fruits of trees, shrubs, and vines composed 90 percent volume of the annual diet. Eight percent of the food consumed was animal matter from mammals, birds, and invertebrates. During all seasons, females used yellow poplar (Liriodendron tulipifera) forests more (P<0.05) than males while males used yellow poplar forests less (P<0.05) than expected; males used black locust (Robinia pseudoacacia) \ black cherry (Prunus serotina) forests more (P<0.05) than females and more (P<0.05) than expected. Shifts in use of chestnut oak (Quercus prinus) \ northern red oak (Q. rubra) forests and northern red oak \ white oak (Q. alba) forests by both males and females in early and late fall was attributed to annual variation in oak mast production, preference for white oak acorns, foraging strategy, and the importance of mountain laurel (Kalmia latifolia) shrub cover in late fall. Seasonal use of domestic fruits at 330 abandoned homesites was determined. Distance-to-nearest-homesite measurements indicated that males were never closer (P>0.10) to homesites than females or random points during any season while females were closer (P<0.001) to homesites than males and random points during summer. Only females were located at homesites (≤ 100m) more (P<0.001) than expected during summer and early fall. Bears consumed apples (Malus spp.) and sweet cherries (Prunus avium) at abandoned homesites mainly in summer, early fall, and late fall. Bears used homesites in late fall more than distance measures indicated. Domestic fruits were an important nutritional food for black bears in relation to total soft fruits eaten.
Master of Science
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Kennish, Robin. "Seasonal patterns of algal availability, influences on diet selection and fitness of the tropical crab grapsus albolineatus." Thesis, Hong Kong : University of Hong Kong, 1995. http://sunzi.lib.hku.hk/hkuto/record.jsp?B17591533.

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Mesquita, Roberto Cesar Magalhaes. "Seasonal Feeding Behavior and Forage Selection by Goats in Cleared and Thinned Deciduous Woodlands in Northeast Brazil." DigitalCommons@USU, 1985. https://digitalcommons.usu.edu/etd/6375.

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The seasonal feeding behavior, forage preferences and body weight responses of goats were studied under three densities of woodland (called caatinga), and under three stocking rates. The experiment was located in the semi-arid tropics of northeastern Brazil at 3 42' South latitude, and 40 21' West longitude at an elevation of 75 meters. Mean annual precipitation of the area is 832 mm. Removing the shrubs and trees increased yields of herbaceous only on partially-cleared sites. Goats gained body weight (kg BW/ha) during the wet season, with the cleared treatment showing the best body weight response per unit of land. However during the dry season, animals lost weight probably due the low quality and quantity of available forage. The botanical composition of goats' diets showed them to be mixed feeders, consuming grasses, forbs and browse in various combinations depending on the season and the array of forage species available. During the dry season standing hay from herbaceous species and regrowth of some woody evergreen species were the principal forages. Animals maintained body weight on this forage. However, leaf litter was an important component of goats' diets during the dry season, but was inadequate for weight maintenance. Goats i n all treatments spent the least time grazing during the wet season and the most time during the beginning of the dry season. They spent the most time lying ruminating during the dry season and the least time during the wet season. Forage quality was probably a limiting factor to effective animal response during the dry season. Goats exhibited dislike for rain and wet conditions. They grazed freely when the temperatures were high (35 to 39 C). However, periods of high temperature corresponded to periods of low relative humidity, perhaps moderating the discomfort factor of combined high temperatures and high humidity.

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Lees, John. "Seasonal adaptations in the energetics and biomechanics of locomotion in the Svalbard rock ptarmigan (Lagopus muta hyperborea)." Thesis, University of Manchester, 2013. https://www.research.manchester.ac.uk/portal/en/theses/seasonal-adaptations-in-the-energetics-and-biomechanics-of-locomotion-in-the-svalbard-rock-ptarmigan-lagopus-muta-hyperborea(867ab906-4d06-4500-a4dc-ac6d27bc1965).html.

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One of the most striking things about many animals is that they can be defined by the ways in which they move. Moving costs metabolic energy and is a significant contributor to the daily energy balance of organisms and therefore fitness. Balancing energy needs is critically important to species inhabiting areas of limited resources. The metabolic cost of locomotion is influenced by physiological, morphological and behavioural factors that vary across species. The influence of these factors within species is less well understood. The objective of my PhD is to elucidate the potential for variation in locomotor performance, in particular the energy consumed and the biomechanics of locomotion within a species, in response to differences in season, sex, age and the nature of the terrain. The Svalbard ptarmigan (Lagopus muta hyperborea) is the only year-round avian resident of the Arctic archipelago of Svalbard. Svalbard is characterized by extreme photoperiodic and climatic conditions, with 24 hours of daylight in summer and continuous darkness in winter, when ice makes food unpredictable. As a result, ptarmigan annually gain significant fat stores, as much as doubling their body mass in winter. The consequences of such large gains in mass upon the metabolic cost and biomechanics of terrestrial locomotion are yet to be quantified. The Svalbard ptarmigan represents a unique opportunity to gain insight into avian adaptations.Using respirometry, I present evidence that winter birds are able to carry their fat stores at no metabolic cost. Using kinematic and force plate data, I show that acquiring fat results in reduced locomotor performance in terms of speed and take-off ability. As well as exhibiting phenotypic variation, male and female Svalbard ptarmigan are behaviourally very different. I present evidence that these behavioural differences are reflected in the metabolic cost of locomotion. In particular, males are both more efficient and faster than female birds during both summer and winter. I suggest that this results from sexual selection upon male locomotor performance. Furthermore, I present data demonstrating that sub-adult males experiencing their first winter possess the same metabolic and speed capabilities of adults. These data may indicate that selection for improved male locomotor performance may act upon sub-adult birds. Regardless of season, age or sex, Svalbard ptarmigan must locomote on a predominantly sloping terrain. The influence of inclines upon the metabolic cost of locomotion in birds is poorly understood. I provide evidence that at the same degree of incline, the cost of lifting 1 kg by 1 vertical metre is similar regardless of season and is therefore dictated by increased positive work. However, this cost varies according to the degree of incline and may be influenced by gait.The principal findings of the 5 first author papers presented are that behavioural, physiological and morphological variation within a species can have significant impacts upon the metabolic cost of locomotion and other aspects of locomotor performance. The potential for intraspecific differences should therefore be taken into account in future research regarding the patterns of energy expenditure in animals.

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Lewis, Mattea A. "Roost Selection and Seasonal Activity of a Remnant Population of Northern Myotis (Myotis septentrionalis) in Pennsylvania." Ohio University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1607005147181749.

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Godin, Claude. "Seasonal occurrence and parasitism of lepidopterous pests of crucifers, and host age selection by a potential control agent, Trichogramma." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape16/PQDD_0005/MQ29702.pdf.

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Godin, Claude 1970. "Seasonal occurrence and parasitism of lepidopterous pests of crucifers, and host age selection by a potential control agent: Trichogramma." Thesis, McGill University, 1997. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=27327.

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During a two years study (1993-1994) in southwestern Quebec, Artogeia rapae and Plutella xylostella were found to be the most important lepidopterous pests of cruciferous crops, followed by Trichoplusia ni and four minor species. The relationship between plant sampling and the use of degree-days, pheromone traps (P. xylostella) or butterflies counts (A. rapae) was assessed for A. rapae and P. xylostella. Three generations of A. rapae were observed annually, with a duration of 319.7 degree-days above $ rm 10 sp circ C (DD sb{10}),$ while P. xylostella had three to four generations with a duration of 277.7 $ rm DD sb{10}.$ Captures of P. xylostella were not linked to the level of infestations. By the end of summer, A. rapae was the most abundant species, especially on broccoli, while P. xylostella was often abundant early in the season. The complex of lepidopterous pests' natural enemies was identified, and the data were analyzed using an illustrated parasitoid web. Fourteen parasitoid and three hyperparasitoid species (12 Hymenoptera, 2 Diptera) were identified. The most important parasitoid, Cotesia rubecula, is a larval parasitoid of A. rapae that is newly established in Quebec. Overall, parasitism of lepidopterous eggs is almost not existent, whereas parasitism and infection of larvae and pupae by pathogens are important, but not significant to reduce butterfly populations. In order to evaluate the potential of oophagous parasitoids, the parasitism of up to 42 species/strains of Trichogramma was studied with different development stages of P. xylostella, A. rapae and T. ni eggs. Generally, Trichogramma females attacked preferably young eggs of a given host species. Females modified the number of offspring according to host size and host age, as fewer offspring emerged from the smallest or the oldest hosts. Host age had no impact on sex allocation. (Abstract shortened by UMI.)

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Burkholder, Braden Osborn. "Seasonal distribution, winter habitat selection and willow utilization patterns of the Shiras moose on the Mount Haggin Wildlife Management Area." Thesis, Montana State University, 2012. http://etd.lib.montana.edu/etd/2012/burkholder/BurkholderB0512.pdf.

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Moose populations are difficult to manage as moose exist at low population densities compared to other ungulates and may use a variety of habitat types. Local knowledge is needed to effectively manage moose populations and limited research has been conducted recently in Montana. This study took place on the Mount Haggin Wildlife Management Area (MHWMA) in southwestern Montana to assist with the management of moose throughout southwestern Montana and establish a baseline for future research. The objectives of this study were to describe seasonal distribution patterns and habitat selection by adult cow moose, with an emphasis on habitat selection during the winter season, and to quantify patterns in willow browse utilization by moose in winter. To accomplish these objectives, I used data from GPS collars on cow moose to determine the basic habitat use patterns and covariates associated with winter habitat selection. Browse surveys of willow were employed to quantify browse utilization on the study area and to determine which environmental covariates were associated with moose browse utilization in winter. Cow moose on the study area were non-migratory and had small winter and summer home ranges. Moose strongly selected for willow cover types and habitat selection was associated with cover type, distance to conifer, distance to willow, and elevation; these relationships changed when snowpack conditions varied. Current browse utilization was low (~10%) and was associated with previously browsed willow, preferred willow species, and willow community width. Based on the habitat selection analysis, both willow and conifer communities were important to cow moose in winter and these results have management implications for habitat conservation and aerial survey methods. The browse utilization analysis showed that browse was notably heterogeneous and would require a large effort to sample browse utilization accurately. However, browse patterns were associated with habitat covariates and habitat managers should take these covariates into account when placing sites for monitoring of willow browse utilization. Overall, the moose population and willow communities around MHWMA appear to be in good health, but threats from climate change, predation, and the potential for overharvest may create population management challenges in the future.

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Carter, Shawn L. "The Habitat Ecology of Bog Turtles (clemmys Muhlenbergii) in Southwestern Virginia." Thesis, Virginia Tech, 1997. http://hdl.handle.net/10919/36953.

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I radiotracked 31 bog turtles (Clemmys muhlenbergii) from May 1995 to December 1996 at 4 study areas in southwestern Virginia. Radio location data were used to provide measures of annual activity, spatial distributions of animals, and habitat selection. The techniques I used in this study were as follows: distance measurements between consecutive locations, home range estimators (Minimum Convex Polygon [MCP] and cluster analysis), compositional analysis of habitat selection, and measurement of microhabitat variables. Results suggest a random pattern of movement by bog turtles within habitats. Average net movements recorded between consecutive locations (separated by < 7 days) during 1995 and 1996 measured 15 m and 20 m for females and 14 m and 23 m for males respectively. Eighty-six percent of all net movements (n = 824) were less than 30 m, whereas only 2% were greater than 100 m. In 1996, average home range sizes (95% MCP, 95% cluster) were 0.47 ha and 0.17 ha for females and were 0.57 ha and 0.13 ha for males. Bog turtles selected wet meadow areas and bulrush (Scirpus spp.) patches more than expected randomly and avoided dry meadow areas and streams. Turtles were located more frequently in mud (x = 24.3 cm) and water (x = 5.2 cm) than expected by random selection (P < 0.001). I found no differences between sexes in movement, home range, or habitat selection by bog turtles. Bog turtles select specialized habitat types and microhabitats within wetlands. Large-scale movements are infrequent and the risk of site isolation may be high if wetland habitat loss continues at historic rates. Future management should protect spatially-close sites which contain multiple habitat types, soft substrate, and pockets of water.
Master of Science

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Sittichok, Ketvara. "Improving Seasonal Rainfall and Streamflow Forecasting in the Sahel Region via Better Predictor Selection, Uncertainty Quantification and Forecast Economic Value Assessment." Thesis, Université d'Ottawa / University of Ottawa, 2016. http://hdl.handle.net/10393/34229.

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The Sahel region located in Western Africa is well known for its high rainfall variability. Severe and recurring droughts have plagued the region during the last three decades of the 20th century, while heavy precipitation events (with return periods of up to 1,200 years) were reported between 2007 and 2014. Vulnerability to extreme events is partly due to the fact that people are not prepared to cope with them. It would be of great benefit to farmers if information about the magnitudes of precipitation and streamflow in the upcoming rainy season were available a few months before; they could then switch to more adapted crops and farm management systems if required. Such information would also be useful for other sectors of the economy, such as hydropower production, domestic/industrial water consumption, fishing and navigation. A logical solution to the above problem would be seasonal rainfall and streamflow forecasting, which would allow to generate knowledge about the upcoming rainy season based on information available before it's beginning. The research in this thesis sought to improve seasonal rainfall and streamflow forecasting in the Sahel by developing statistical rainfall and streamflow seasonal forecasting models. Sea surface temperature (SST) were used as pools of predictor. The developed method allowed for a systematic search of the best period to calculate the predictor before it was used to predict average rainfall or streamflow over the upcoming rainy season. Eight statistical models consisted of various statistical methods including linear and polynomial regressions were developed in this study. Two main approaches for seasonal streamflow forecasting were developed here: 1) A two steps streamflow forecasting approach (called the indirect method) which first linked the average SST over a period prior to the date of forecast to average rainfall amount in the upcoming rainy season using the eight statistical models, then linked the rainfall amount to streamflow using a rainfall-runoff model (Soil and Water Assessment Tool (SWAT)). In this approach, the forecasted rainfall was disaggregated to daily time step using a simple approach (the fragment method) before being fed into SWAT. 2) A one step streamflow forecasting approach (called as the direct method) which linked the average SST over a period prior to the date of forecast to the average streamflow in the upcoming rainy season using the eight statistical models. To decrease the uncertainty due to model selection, Bayesian Model Averaging (BMA) was also applied. This method is able to explore the possibility of combining all available potential predictors (instead of selecting one based on an arbitrary criterion). The BMA is also capability to produce the probability density of the forecast which allows end-users to visualize the density of expected value and assess the level of uncertainty of the generated forecast. Finally, the economic value of forecast system was estimated using a simple economic approach (the cost/loss ratio method). Each developed method was evaluated using three well known model efficiency criteria: the Nash-Sutcliffe coefficient (Ef), the coefficient of determination (R2) and the Hit score (H). The proposed models showed equivalent or better rainfall forecasting skills than most research conducted in the Sahel region. The linear model driven by the Pacific SST produced the best rainfall forecasts (Ef = 0.82, R2 = 0.83, and H = 82%) at a lead time of up to 12 months. The rainfall forecasting model based on polynomial regression and forced by the Atlantic ocean SST can be used using a lead time of up to 5 months and had a slightly lower performance (Ef = 0.80, R2 = 0.81, and H = 82%). Despite the fact that the natural relationship between rainfall and SST is nonlinear, this study found that good results can be achieved using linear models. For streamflow forecasting, the direct method using polynomial regression performed slightly better than the indirect method (Ef = 0.74, R2 = 0.76, and H = 84% for the direct method; Ef = 0.70, R2 = 0.69, and H = 77% for the indirect method). The direct method was driven by the Pacific SST and had five months lead time. The indirect method was driven by the Atlantic SST and had six months lead time. No significant difference was found in terms of performance between BMA and the linear regression models based on a single predictor for streamflow forecasting. However, BMA was able to provide a probabilistic forecast that accounts for model selection uncertainty, while the linear regression model had a longer lead time. The economic value of forecasts developed using the direct and indirect methods were estimated using the cost/loss ratio method. It was found that the direct method had a better value than the indirect method. The value of the forecast declined with higher return periods for all methods. Results also showed that for the particular watershed under investigation, the direct method provided a better information for flood protection. This research has demonstrated the possibility of decent seasonal streamflow forecasting in the Sirba watershed, using the tropical Pacific and Atlantic SSTs as predictors.The findings of this study can be used to improve the performance of seasonal streamflow forecasting in the Sahel. A package implementing the statistical models developed in this study was developed so that end users can apply them for seasonal rainfall or streamflow forecasting in any region they are interested in, and using any predictor they may want to try.

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Miller, Aileen Kilpatrick. "Site Selection by Migratory Shorebirds in Oregon Estuaries Over Broad and Fine Spatial Scales." PDXScholar, 2012. https://pdxscholar.library.pdx.edu/open_access_etds/443.

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Many migratory shorebirds rely on estuaries as stop-over sites to refuel during migration, and the loss of stop-over sites is a primary threat to shorebird populations on the West Coast of the United States (e.g. Calidris alpina pacifica, C. mauri). Conservation and research has focused on the largest of these sites; however, smaller estuaries also host thousands of migratory shorebirds. Furthermore, the reasons for site selection are largely unknown. Estuarine inter-tidal microhabitats are non-uniform and both abiotic and biotic factors may serve as predictors of whether an abundance of shorebirds will use a site. I investigated shorebird site selection on broad and fine scales within Oregon estuaries. To identify factors that relate to shorebird abundance on large spatial scales, I compiled shorebird abundance data from estuaries throughout the Pacific Northwest as well as data on site quality factors. To investigate site selection on a finer scale I measured shorebird abundance, habitat characteristics, and food resources―invertebrates and a newly considered source, biofilm―within two Oregon estuaries during the fall migration period. Finally, I examined whether channels are preferentially used by foraging Calidrid shorebirds by conducting observations during the spring migration. I investigated whether channels may be superior foraging habitat possibly because prey are more abundant, are found at shallower depths, or because sediments are more penetrable (increasing the opportunity for shorebird probing) by taking infauna cores and measuring force required to probe in the sediment at channel and open mudflat sites. Among estuaries, shorebird densities in spring were best predicted by estuary size, as opposed to the amount of any one habitat. During fall migration, the amount of grassland in the surrounding watershed was also a good predictor, pointing to the probable importance of roost sites as well as feeding grounds. The amount of infauna also related to the density of shorebirds using a site. Within estuaries, shorebird distribution in the inter-tidal region was not generally predicted by prey abundance. Channels were used preferentially by shorebirds, and infauna abundance along channels was greater than in the surrounding mudflats. The more penetrable sediments of the channel also made it easier for shorebirds to probe and capture prey. Identification of these large-scale and fine-scale factors that influence site quality for migratory shorebirds will assist land and wildlife managers' efforts to protect these species.

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Heymans, André. "Managing an agricultural commodities portfolio in South Africa with pairs trading / André Heyman." Thesis, North-West University, 2007. http://hdl.handle.net/10394/2308.

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Lamichhaney, Sangeet. "The genetic basis for adaptation in natural populations." Doctoral thesis, Uppsala universitet, Institutionen för medicinsk biokemi och mikrobiologi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-279969.

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Many previous studies in evolutionary genetics have been based on few model organisms that can be reared at ease in the laboratory. In contrast, genetic studies of non-model, natural populations are desirable as they provide a wider range of adaptive phenotypes throughout evolutionary timescales and allow a more realistic understanding of how natural selection drives adaptive evolution. This thesis represents an example of how modern genomic tools can be effectively used to study adaptation in natural populations. Atlantic herring is one of the world’s most numerous fish having multiple populations with phenotypic differences adapted to strikingly different environments. Our study demonstrated insignificant level of genetic drift in herring that resulted in minute genetic differences in the majority of the genome among these populations. In contrast, a small percentage of the loci showed striking genetic differentiation that were potentially under natural selection. We identified loci associated with adaptation to the Baltic Sea and with seasonal reproduction (spring- and autumn-spawning) and demonstrated that ecological adaptation in Atlantic herring is highly polygenic but controlled by a finite number of loci. The study of Darwin’s finches constitutes a breakthrough in characterizing their evolution. We identified two loci, ALX1 and HMGA2, which most likely are the two most prominent loci that contributed to beak diversification and thereby to expanded food utilization. These loci have played a key role in adaptive evolution of Darwin’s finches. Our study also demonstrated that interspecies gene flow played a significant role in the radiation of Darwin’s finches and some species have a mixed ancestry. This thesis also explored the genetic basis for the remarkable phenotypic differences between three male morphs in the ruff. Identification of two different versions of a 4.5 MB inversion in Satellites and Faeders that occurred about 4 million years ago revealed clues about the genetic foundation of male mating strategies in ruff. We highlighted two genes in the inverted region; HSD17B2 that affects metabolism of testosterone and MC1R that has a key role in regulating pigmentation, as the major loci associated with this adaptation.

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Hall, Anna Marie. "Foraging behaviour and reproductive season habitat selection of northeast pacific porpoises." Thesis, University of British Columbia, 2011. http://hdl.handle.net/2429/37218.

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Behavioural observations are fundamental to understanding and defining the habitat needs of animals. I compiled the behavioural repertoires reported for harbour (Phocoena phocoena) and Dall’s porpoise (Phocoenoides dalli) by classifying the life processes of phocoenids into 12 descriptive categories. This range-wide review revealed complex sexual and social behaviours, similar foraging behaviours and breeding site fidelity, as well as differences in habitat selection between these two northern hemisphere species. I also conducted a fine-scale field study of harbour porpoise foraging behaviour at two sites in Juan de Fuca Strait (British Columbia) using point transect survey data (2007–2008), and platforms of opportunity data (1995–1996, 1998–2008) to determine the physical conditions under which harbour porpoise foraged and the extent to which they displayed specialised behaviours. I examined harbour porpoise presence, density and group sizes relative to tidal currents, tidal variation, lunar phase, lunar position, solar position, diurnality, seasonality and presence of conspecifics—and found that greater numbers of harbour porpoise occurred on the ebb current during the spring tides. Numbers of porpoise increased three-fold between April and October, when calves and high-energy behaviours were also more prevalent. To identify porpoise breeding habitat in the inland waters of southern British Columbia and northwestern Washington, I used systematically and opportunistically collected sightings of harbour and Dall’s porpoise (1991–2008), and compared group sizes and frequency of occurrences for both species relative to bathymetry and tidal speeds. Overall, I found that both species selected bathymetrically differentiated habitats that were characterized by high rates of tidal mixing (with harbour porpoise preferring regions ≤100 m, and Dall’s porpoise preferring 151 – 250 m). Spatial analysis identified two separate areas that may be species-specific breeding habitats—the first to be identified for either species in this region. In summary, harbour porpoise maintained stable group sizes and used tidally well-mixed foraging sites on a temporary but predictable basis. Dall’s porpoise were associated with these same areas, but habitat partitioning associated with differences in bathymetry occurred in important breeding areas that may account for the coastal parapatric distribution of these two high trophic level predators.

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Bonamour, du Tartre Suzanne. "Breeding with seasons : variability, heritability, and natural selection of phenological plasticity in a wild bird." Thesis, Montpellier, 2019. http://www.theses.fr/2019MONTG070.

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La plasticité phénotypique – l’expression par un génotype de différents phénotypes en fonction de l’environnement – est un processus omniprésent dans la nature. Les changements de phénologie sont actuellement l’une des principales réponses au changement climatique. Bien qu’elle ait permis des réponses adaptatives aux variations environnementales par le passé, la plasticité phénotypique pourrait, dans un futur proche, ne plus être adaptative en raison des transformations importantes et rapides des écosystèmes. Dans un tel contexte, l’évolution de la plasticité phénotypique pourrait être cruciale à la persistance des populations, cela nécessitant que la plasticité soit héritable et soumise à la sélection naturelle. Un des exemples les plus étudiés de plasticité phénologique est la variation de la date de ponte en fonction de la température chez les oiseaux. Les températures printanières sont en effet l’indice environnemental le plus corrélé aux changements de phénologie chez la plupart des espèces de passereaux en région tempérée. En se basant sur les suivis à long-terme de quatre populations naturelles de mésanges bleues (Cyanistes caeruleus) en région méditerranéenne, cette thèse s’intéresse à la variabilité, l’héritabilité et la sélection naturelle sur la plasticité phénotypique de la phénologie de la reproduction. Premièrement, dans une revue bibliographique sur l’influence du changement climatique sur la plasticité phénotypique, nous avons mis en évidence l’importance des effets probables du changement climatique sur la fiabilité des indices environnementaux. Ce point a fait l’objet d’une étude plus poussée dans nos quatre populations de mésanges ainsi que chez leurs principales proies (chenilles), mettant en évidence des différences entre populations provenant d’habitats différents. Deuxièmement, pour mieux comprendre les déterminants de la variation intra-individuelle de la phénologie de la date de ponte, nous avons exploré comment le processus de vieillissement affecte l’expression de la plasticité phénotypique de la date de ponte en fonction de la température, révélant une plasticité plus forte chez les femelles matures que chez les femelles jeunes ou âgées. De plus, nous avons évalué la plasticité de la sénescence de reproduction en fonction de la qualité environnementale expérimentée par les oiseaux au cours de leur vie, et montré que les individus dans un bon environnement vieillissent plus vite. Enfin, afin de mieux cerner le potentiel évolutif de la phénologie de la reproduction chez la mésange bleue, nous avons estimé l’héritabilité de la plasticité et mis en œuvre de nouvelles méthodes pour estimer la sélection naturelle sur les normes de réaction. Nous avons détecté de l’héritabilité de la plasticité ainsi que de la sélection, nous prédisons donc une réponse à la sélection de la plasticité de la date de ponte
Phenotypic plasticity – the expression by a single genotype of different phenotypes according to the environment – is ubiquitous in nature. Changes in phenology through plastic modulations are currently one of the main responses to climate change in the wild. Despite allowing adaptive and fast responses to environmental variation in the past, phenotypic plasticity may not be adaptive anymore in the new and/or extreme environmental conditions created by rapid global change. In this context, evolution of phenotypic plasticity could be crucial for population adaptation and persistence. One of the most studied examples of phenological plasticity is the variation of avian egg-laying date according to spring temperature which acts as an environmental cue in most of passerines species in temperate regions. Taking advantage of the long-term monitoring of four wild populations of Mediterranean blue tits (Cyanistes caeruleus), this thesis investigates the variability, heritability of and natural selection on phenotypic plasticity of reproductive phenology. First, a review of the influence of climate change on phenotypic plasticity highlighted the importance of potential changes in cue(s) reliability for plasticity to remain adaptive, a point we further explored in our four blue tits populations and their main preys (caterpillars), showing differences among populations from different habitats. Second, to better understand the drivers of within-individual variation of laying date phenology we evaluated how ageing affects plasticity of laying date in response to temperature, and revealed stronger plasticity in mature compared to young or old females. Moreover, we assessed plasticity of reproductive senescence according to the environmental quality experienced by birds during their lifetime and showed that individuals experiencing good environments age faster. Finally, to improve our knowledge of the evolutionary potential of reproductive phenology in this species, we estimated the heritability of laying date and implemented methods to estimate natural selection on laying date and its plasticity. We showed both heritability of and selection on plasticity, we thus expect response to selection

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Peña, Ortega Margarita Gisela. "Evaluation of three recurrent selection methods in two short-season maize (Zea mays L.) synthetics." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0024/NQ51044.pdf.

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Wyma, Rindert. "Birds of the riparian corridors of Potchefstroom, South Africa / Rindert Wyma." Thesis, North-West University, 2012. http://hdl.handle.net/10394/9545.

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A riparian ecosystem is the area between the aquatic and terrestrial setting of a stream, and serves as a corridor and habitat for birds. Several riparian ecosystems are located in urban environments, and three main riparian corridors are located in Potchefstroom. They are the Mooi River, Wasgoed Spruit, and Spitskop Spruit, which encompass a wide range of different vegetation types and anthropogenic factors. Therefore, different habitat types for birds occur along the riparian corridors of Potchefstroom. Factors such as food and water availability, nesting sites, competition, predation, learning, presence of other species, and those species that are able to adapt to environmental changes influence the avian diversity and communities along riparian corridors. The hypothesis is that bird variables along the riparian corridors in Potchefstroom are affected by vegetation, anthropogenic, and seasonal influences. To investigate these affects, two secondary objectives were formulated. The first was to characterise riparian avian habitats (CAHs) according to vegetation and anthropogenic factors, and the second was to identify temporal and spatial changes in avian variables. The three streams were divided into 79 consecutive transects, each 300 m long. The study area consisted of: 17 transects along Spitskop Spruit, 12 along Wasgoed Spruit and 50 along the Mooi River. Bird observations were conducted monthly from June 2006 to June 2007. Birds that were observed with a perpendicular distance ≤ 30 meters towards the streams were included in the results. The bird species that were observed were also classified into different nesting and feeding guilds. Environmental data recorded included: vegetation structure (estimated cover percentages and height classes of trees, shrubs, grasses, herbs, sedges, and reeds), anthropogenic structures (estimated cover percentages of roads, footpaths, bridges, electrical pylons, houses, and drainage pipes), and the presence of informal settlers along each transect (the mean number of people and the space they occupy). Vegetation was monitored in summer– (February 2007 until April 2007) and winter months (June 2007 until August 2007). The anthropogenic structures and the presence of informal settlers (anthropogenic factors) were monitored simultaneously with the bird counts. Transect-time profiles were drawn for the four parameters, which differed on spatial and time scales. Multivariate analyses included non-metric multidimensional scaling (NMS), cluster analysis, and indicator species analysis. Cluster analyses and NMS bi-plots were used to define characterised avian habitats (CAHs). Two types of CAHs were characterised: Summer CAHs (summer vegetation and anthropogenic factors) and Anthropogenically CAHs (Anthropogenic factors alone). Bird species were then ordinated with the summer and anthropogenically CAHs on NMS successional vector graphs. The successional vectors illustrate the avian community trajectories of the different CAHs. Indicator species analyses were performed to describe associations between the bird species and the summer and anthropogenically CAHs. The summer and anthropogenic CAHs that were characterised had different avian community trajectories and different species were associated with these CAHs. Different levels in avian diversity appeared among these CAHs, and convergence and divergence in communities appeared among these CAHs. Birds also selected their habitats according to feeding and nesting behaviours. Consequently, it can be deduced that environmental factors such as vegetation structures and anthropogenic factors, as well as seasonality, had an effect on the distribution of birds along the riparian corridors of Potchefstroom.
Thesis (Master of Environmental Sciences)--North-West University, Potchefstroom Campus, 2013

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Williams, Emily Jean. "Grasshopper sparrows on the move: patterns and causes of within-season breeding dispersal in a declining grassland songbird." Thesis, Kansas State University, 2016. http://hdl.handle.net/2097/32705.

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Master of Science
Biology
Alice Boyle
Dispersal is a behavior common to virtually all taxa with important consequences for gene flow, demography, and conservation. Mobile animals such as birds frequently engage in breeding dispersal, but the factors shaping this behavior are not well understood. In mid-continental grasslands, preliminary evidence suggested that Grasshopper Sparrows (Ammodramus savannarum) engaged in breeding dispersal within a single breeding season. This intriguing pattern shaped my research questions: (1) what are the patterns of within-season breeding dispersal in Grasshopper Sparrows? (2) why do some individual sparrows disperse, and others do not? and (3) what shapes settlement decisions following dispersal? I tested hypotheses based on spatial and temporal variation in nest predation, nest parasitism, and food availability. I studied Grasshopper Sparrows at 18 experimentally-managed watersheds with different fire and grazing regimes at Konza Prairie Biological Station during 2013-2015. To describe patterns, I combined re-sighting of 779 marked individuals, territory mapping, and radio-telemetry to quantify territory densities, turnover, and dispersal distances. To determine if nest predation or nest parasitism affected dispersal, I monitored the fate of 223 nests. I estimated food intake rates using plasma metabolites, and prey availability using sweep sampling. Densities of territorial Grasshopper Sparrows varied seasonally in management-specific ways. Turnover was remarkably high, with over half of territorial males being replaced each month. Over a third of males changed territories within-season, dispersing 0.1-9 km between breeding attempts. Dispersal decisions were related to past nest predation, but not nest parasitism. Dispersal likely yields fitness benefits, as sparrows that dispersed increased their chances of nest survival by 23% relative to site-faithful individuals. However, food availability did not affect settlement decisions. My study provides the first evidence of within-season breeding dispersal in Grasshopper Sparrows, and represents one of few tests of alternative hypotheses explaining dispersal decisions of songbirds. My results are consistent with a growing literature on the role of predation shaping dispersal, but suggest, somewhat surprisingly, that food is not important in post-dispersal habitat selection. High dispersal capacity coupled with adaptability to temporal and spatial change may be typical of grassland songbirds, implying that demographic studies and management decisions must consider their mobility for conservation.

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Teichert, Nils. "Variabilité des traits d’histoire de vie chez les Gobiidae (Sicydiinae) amphidromes de l’île de la Réunion : Sicyopterus lagocephalus (Pallas, 1770) et Cotylopus acutipinnis (Guichenot, 1863)." Thesis, Pau, 2012. http://www.theses.fr/2012PAUU3024/document.

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Les Sicydiinae amphidromes constituent une part importante des peuplements piscicoles insulaires de la région Indo-Pacifique et sont vulnérables à de nombreuses pressions anthropiques (i.e. pêcherie, dégradation et fragmentation des habitats). La reproduction a lieu en eau douce, puis les jeunes dévalent en mer où ils débutent leur croissance pendant quelques mois avant de coloniser les rivières. L’objectif est d’acquérir des connaissances sur les traits de vie de S. lagocephalus (cosmopolite) et de C. acutipinnis (endémique). Les travaux de terrain démontrent que le choix de l’habitat quotidien est fortement lié aux interactions sociales, alors que l’habitat de fraie montre une forte sélection pour des conditions morphodynamiques favorisant l’oxygénation des oeufs. Les mâles sélectionnent des sites de ponte et gardent les oeufs. L’étude expérimentale de la survie en eau douce confirme que tous les embryons libres possèdent la capacité à rejoindre la mer. L’analyse des traits de vie marins à partir des otolithes des post-larves révèle des variations saisonnières d’âge et de taille au recrutement, en lien avec la croissance et la température marine. L’examen histologique des ovaires permet de décrire les variations spatiales et temporelles de l’activité de reproduction chez les femelles en rivière et de déterminer la fécondité et la taille de première reproduction. Les variations inter et intra-spécifiques des traits de vie sontcomparées en lien avec la répartition géographique des deux espèces. Ces travaux permettent d’identifier des perspectives concrètes dans le domaine de la gestion et de la conservation sur la base des caractéristiques de la stratégie amphidrome
Amphidromous Sicydiinae are particularly widespread among fish freshwater assemblages of the Indo-Pacific region and are vulnerable to anthropogenic pressures (i.e. fishery, degradation and fragmentation of habitats). Spawning and hatching happen in freshwater, then offspring drift downstream to the sea where they begin their growth for a few months before recruiting in the rivers. This study aims at acquire knowledge about life traits of S. lagocephalus (cosmopolite) and C. acutipinnis (endemic). Field sampling shows that the usual habitat choice is related to social interactions, whereasspawning habitat shows a strong selection for morphodynamic conditions which favor eggs oxygenation. Males select spawning sites and care for the eggs. The experimental study of freshwater survival confirms that free embryos survival and swimming capacities are enough to drift to the ocean. Marine life history analysis, based on postlarvae otoliths examination, reveals a seasonal variation of both age and size-atrecruitment related to the larval growth rate and the sea temperature. Histological examination of ovaries is used to describe the spatial and temporal variation of reproductive activity of mature females in the rivers, and to determine fecundity and size at first reproduction. Inter and intra-specific variations of life history traits are compared in relation to the respective geographical distribution of both species. This study identifies concrete prospects for management and conservation based on the features of amphidromous life history strategy

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Humphries, Sarah S. Osborne Barbara. "An examination of the relationship between end of season conference rankings and the bowl game selection process in the Atlantic Coast Conference." Chapel Hill, N.C. : University of North Carolina at Chapel Hill, 2009. http://dc.lib.unc.edu/u?/etd,2738.

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Thesis (M.A.)--University of North Carolina at Chapel Hill, 2009.
Title from electronic title page (viewed Mar. 10, 2010). "... in partial fulfillment of the requirements for the degree of Master of Arts in the Department of Exercise and Sport Science Sport Administration." Discipline: Exercise and Sports Science; Department/School: Exercise and Sport Science.

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Munzhedzi, Mukondeleli. "Effect of haverst season and ripening duration on the physico-chemical properties of new 'fuerte-type' avocando fruit selections during ripening." Thesis, University of Limpopo, 2016. http://hdl.handle.net/10386/1810.

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Thesis (MSc. Agriculture (Horticulture)) -- University of Limpopo, 2016
The Agricultural Research Council-Institute for Tropical and Subtropical Crops (ARC-ITSC) is continuously developing new avocado selections, in order for the South African Avocado Industry (SAAI) to remain competitive in various international avocado markets. However, information on the response of some of these selections, including ‘Fuerte 2 and 4’, ‘BL1058’ and ‘H287’ to low temperature storage and ripening physiology, has not been investigated. Thus, the objective of this study was to evaluate the effect of harvest season and ripening duration on the physico-chemical properties of newly developed ‘Fuerte-type’ avocado fruit selections during ripening. ‘Fuerte-type’ avocado fruit were indexed for maturity using moisture content, thereafter harvested and stored at 5.5°C for 28 days during the 2014 and 2015 harvest seasons. The experiment comprised five treatments: control (commercial ‘Fuerte’), ‘Fuerte 2 and 4’, ‘BL1058’ and ‘H287’ arranged as a factorial in a completely randomised design (RCD) with 3 replicates. The treatment factors were: (i) 2 x harvest seasons, (ii) 5 x selections and (iii) 6 x ripening days. After withdrawal from low storage temperature, fruit were ripened at ambient temperature. During ripening, the following physico-chemical properties were evaluated; external chilling injury, electrolyte leakage, mass loss, firmness, respiration rate and peel colour. Results showed that selections and harvest seasons had no significant effect (P=0.668) on the moisture content of the evaluated ‘Fuerte-type’ avocado fruit. After withdrawal from low storage temperature, there was a significant interaction (P˂0.05) between selections and harvest seasons on external chilling injury and electrolyte leakage. Results further showed that external chilling injury correlated with electrolyte leakage during both harvest seasons. Treatment factors had no significant effect (P=0.997) on mass loss. Similarly, treatment factors had no significant effect (P=0.139) on firmness. However, selection ‘H287’ had hard skin with an average firmness of 83.44 densimeter units during ripening in both harvest seasons. Treatment factors were highly significant (P˂0.05) on respiration rate. Respiration rate followed a climacteric pattern and the magnitude of climacteric peak and day of occurrence varied amongst selections during both harvest seasons. Ripening percentage differed significantly (P˂0.05) amongst harvest seasons, selections and ripening days. Treatment factors had no significant effect on lightness (P=0.711), chroma (P=0.378) and hue angle (P=0.536) skin colour parameters,however, variations were recorded as a result of the cold damage black spots. The results indicated that the ‘Fuerte-type’ avocado selections had poor storage qualities. Further studies are required to evaluate physico-chemical properties during low storage temperature and the effect of season, production conditions and maturity level on development of chilling injury. In addition, studies on application of treatments to reduce chilling injury symptoms and analysis of bioactive compounds should be considered for conclusive recommendations. Thereafter, the selections can be planted in different production regions to assess and select the best producing and quality combinations for a given region as part of phase III of the project
Agricultural Sector Education Training Authority (AgriSeta) and National Research Foundation (NRF)

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Aragão, Thiago Ricielli de Paula. "Interação testecrosses por épocas de semeadura e implicações para o melhoramento de milho." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/11/11137/tde-25032013-163700/.

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O cultivo do milho safrinha tem se expandido consideravelmente nos ultimos anos. Porem devido as condicoes ambientais contrastantes entre safra e safrinha, deve ocorrer pronunciada interacao genotipos x safras, indicando que os genotipos selecionados para a safra podem nao ser adequados para a safrinha. Assim, os objetivos deste trabalho foram investigar a magnitude e natureza da interacao genotipos x safras e a necessidade de conduzir programas de melhoramento de milho distintos para o cultivo de safra e safrinha. Foram utilizadas 100 progenies S1fs derivadas do cruzamento entre as linhagens endogamicas L08- 05F e L38-05D, as quais foram retrocruzadas com ambas as linhagens genitoras e, posteriormente, estas foram cruzadas com a linhagem endogamica L02-03D para obtencao de 200 testecrosses (100 RC1 TC e 100 RC2 TC ). Os testecrosses obtidos foram avaliados nos ambientes de safra e safrinha em dois anos agricolas no municipio de Piracicaba/SP no delineamento ?¿-latice com duas repeticoes por ambiente por ano. Os caracteres analisados foram producao de graos (PG), prolificidade (PROL), acamamento e quebramento de plantas (ACQ), altura de planta (AP) e de espiga (AE), posicao relativa da espiga (PRE), florescimento masculino (FM) e feminino (FF) e intervalo entre florescimentos (IF). Diferencas entre as medias nas duas safras foram significativas para todos os caracteres, reduzindo significativamente a PG na safrinha devido a menor disponibilidade hidrica. A variancia genetica dos testecrosses para PG na safrinha foi inferior a da safra para os testecrosses RC2 TC , enquanto que para os testecrosses RC1 TC a variancia genetica nao diferiu de zero na safrinha. Consequentemente, o coeficiente de herdabilidade na safrinha para os RC1 TC nao diferiu de zero e os RC2 TC apresentaram coeficientes de herdabilidade de magnitudes similares nas duas safras. Para os demais caracteres as magnitudes das variancias geneticas e coeficientes de herdabilidade diferiram entre as safras e os dois grupos de testecrosses. As magnitudes dos componentes da interacao testecrosses x safras mostraram que o tipo complexa explica a maior parte da interacao, sendo causada pelas baixas magnitudes de correlacoes entre os caracteres nas diferentes safras. As respostas diretas e indiretas a selecao mostraram que a selecao direta foi mais eficiente que a indireta em todas as situacoes, com excecao daquelas em que nao foi detectada variancia genetica na safrinha. As respostas a selecao baseadas nas medias das safras resultaram em progressos na safra e na safrinha proximos aos observados pela selecao direta. Porem, a coincidencia de testecrosses selecionados em ambas as safras foi muito baixa para os dois testecrosses. Assim, os resultados deste estudo sugerem que os programas de melhoramento de milho devem ser distintos para safra e safrinha.
Maize second crop season, known as gsafrinhah, has increased considerably in the last years in Brazil. However, because of the different environmental conditions between the two crop seasons strong genotype by environment interaction is expected to occur, and then maize genotypes selected in the first crop season (known as gsafrah) could not be those ones that would be selected in the safrinha. Thus, objectives of this research were to investigate the magnitude and the nature of the genotype x crop season interaction and whether separate maize breeding programs for each crop season should be conducted. One hundred S1Ls progenies developed from a population produced from the cross of inbred lines L08-05F (P1) and L38-05D (P2), were backcrossed to both parental inbred lines and, subsequently, these backcrosses were crossed to the inbred line L02-03D giving rise to the 200 testcrosses, thereafter named as TBC1 and TBC2 for the backcrosses to P1 and P2, respectively. The testcrosses were evaluated in two crop seasons in two years at the Piracicaba city, Sao Paulo State, in the ?¿-lattice designs with two replications per crop season and year. The traits analyzed were grain yield (GY), prolificacy (PROL), plant lodging (PL), plant (PH) and ear (EH) heights, ear placement (EP), days to anthesis (DA), days to silking (DS), and anthesissilking interval (ASI). Significant differences for the means of all traits in the two crop seasons were detected, and GY reduced significantly in the safrinha because of the moisture stress. The magnitude of the genetic variance for GY in the safrinha was inferior to that in the safra for the TBC2, and for the TBC1 this parameter did not differ from zero in the safrinha. Consequently, the heritability coefficient in the safrinha for the TBC1 did not differ from zero and the TBC2 presented similar magnitudes of the heritability coefficients in both crop seasons. For the other traits, the magnitudes of the genetic variances and of the heritability coefficients were different between the crop seasons and for the two sets of testcrosses. The magnitudes of the components of the interactions testcrosses x crop seasons showed that the complex type i.e., the cross-over interaction type, accounted for the major part of the interactions, which were due to the low magnitudes of the correlations of the traits in the two crop seasons. Estimates of the direct and indirect responses to selection showed that the direct selections were more efficient than the indirect selections, except to that trait in which the genetic variance did not differ from zero in the safrinha. The responses to selection based on the means of the two crop seasons presented similar magnitudes of the direct responses in both crop seasons. However, the coincidence of testcrosses selected in the two crop seasons was very low for both sets of testcrosses. Therefore, the results of this study suggest that separate maize breeding programs should be conducted for each crop season.

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31

Jackson, Abigail. "Parasitic gastroenteritis in calves during their first season at grass : the potential for a performance-based targeted selective anthelmintic treatment programme." Thesis, University of Glasgow, 2013. http://theses.gla.ac.uk/4290/.

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The work described in this thesis was designed to investigate the current impact of parasitic gastroenteritis on organic and conventional dairy farms in first season grazing youngstock in Scotland, and to elucidate a marker of significant parasite challenge within individual calves, in order to target these calves with an anthelmintic treatment. It was felt particularly that any recommendations should be practical and easily implemented on-farm, and optimise anthelmintic usage, with regard to animal health, welfare and performance on both organic and conventional farms. There is world-wide recognition that nematode parasite infections are one of the greatest causes of lost productivity of grazing livestock. In the UK, the single most important cause of parasitic gastroenteritis in cattle is infection with the abomasal nematode, Ostertagia ostertagi, although concomitant infection with the less pathogenic intestinal nematode, Cooperia oncophora is common. Often, non-organic (conventional) producers use anthelmintic treatment programmes that prevent disease or treat all animals in a group without necessarily considering the basic epidemiological information needed for an optimal strategic control. Organic producers are encouraged to avoid this approach, thus it may be hypothesised that organic livestock harbour higher parasite burdens compared to livestock in conventional systems. However, little information is available on current UK organic dairy anthelmintic use and subsequent parasite challenge to youngstock. This thesis aimed to investigate current management practices on three Scottish organic farms compared to three Scottish conventional farms and examine different ways of assessing parasite challenge (including novel markers) with a view to the implementation of a targeted selective treatment (TST) programme. Liveweight gain assessment by means of weigh-bands as a tool to investigate the effect of parasitism on the host was also examined. In year one of the study, the six farms were visited on four occasions throughout the grazing season where fifteen first season grazers on each farm had their liveweight measured (weigh-band or weigh-scale), a faecal egg count (FEC) recorded and plasma pepsinogen, plasma fructosamine and Ostertagia ostertagi antibody concentrations measured. Knowledge of the epidemiology and pathophysiology of gastrointestinal nematode infestation has led to the identification of parasitic biomarkers for use either as a diagnostic tool or for providing a threshold for anthelmintic treatment. Faecal egg counts (FEC) are the most widely used parameter, both clinically and in studies on gastrointestinal nematode infections of ruminants, because of their relative convenience and low cost. Organic producers are encouraged to use faecal egg counts in order to direct anthelmintic treatment to calves, or groups of calves, that have counts of 200 eggs per gram or more (Soil Association, 2010). The recent launch of COWS (Control of Worms Sustainably in Cattle) in May 2010 - an initiative to prevent widespread anthelmintic resistance and to use anthelmintics appropriately in cattle in the UK - has also seen conventional farmers encouraged to use faecal egg counts in the same manner as their organic counterparts (Taylor, 2010i). None of the biomarkers, including FEC, investigated in the study reflected liveweight gain adequately to use in a targeted selective anthelmintic treatment programme. An ideal biomarker would give indication of calves that would most benefit from anthelmintic treatment before liveweight gain was affected. The biomarkers in this study indicated presence of gastrointestinal parasitism but could not target the animals that had poor liveweight gains. The emphasis on FEC in advice to farmers regarding the need for anthelmintic treatment requires re-evaluation. The data from year one showed that the conventionally farmed first season grazers (FSG) had significantly higher liveweight gains than the organically farmed calves. Anthelmintic treatment was applied to the organic calves in the study when the calves were known to be harbouring gastrointestinal parasite infection from positive faecal egg counts. The organically farmed first season grazers in this study had high gastrointestinal parasite challenge, indicated by parasite-based markers such as FEC and plasma pepsinogen concentration. The conventional producers in this study exposed FSG to 652% more days of anthelmintic than the organic producers and gained superior liveweight gains over the grazing season. Essentially, the organic producers fulfilled the ethos of organic production, reducing anthelmintic usage and showing necessity of anthelmintic treatment. However, subclinical and clinical parasitic gastroenteritis reduces animal welfare, the essence of the organic ethos. The organic industry needs to investigate whether there is a superior alternative to FEC that still promotes the organic ethos and reduces subclinical and clinical parasitic gastroenteritis. The possibility of using liveweight gain as a marker for anthelmintic treatment was investigated. An accurate assessment of liveweight is necessary if calf liveweight gain is to be calculated accurately and used as a threshold for anthelmintic treatment. Cattle weigh-scales are expensive and often not available on farm, particularly where youngstock may be grazing at pasture and gathered in the field for handling. With this in mind, cattle weigh-bands, which measure heart girth and relate this to liveweight, have been devised and used in practice in order to estimate cattle liveweight. Realistically, if a liveweight gain threshold were to be recommended for use on farms in the UK, the weigh-band must estimate liveweight and hence liveweight gain accurately. Given that many farmers do not possess weigh-scales on farm, use of heart-girth measurements to estimate liveweight gain is the best option available to farmers currently. Year two involved the implementation of a targeted selective anthelmintic treatment (TST) programme on two organic farms and one conventional farm; all were previously involved in the year one study. Anthelmintic treatment was applied only to FSG calves growing at <0.75kg/day at two points in the grazing season. Organic Farm 1 (O1) and Organic Farm 2 (O2) increased the liveweight gain of the FSG in year two by 50% and 44% respectively. Farm O2 exposed the FSG to 1160% more days of anthelmintic than in 2009; however, approximately 10% of the group were left untreated. Conventional FSG showed reduced liveweight gain from the previous year by 19%. However, respiratory disease was present on-farm also and may have confounded findings. Applying a performance-based targeted anthelmintic regime treatment in the field is possible and using it on farms where anthelmintic treatment was already minimal, such as organic farms, increased liveweight gain in first season grazers without significantly increasing anthelmintic treatment. Applying a TST regime to a conventional farm where previously a suppressive anthelmintic treatment had been applied may have reduced liveweight gain in the first season grazers (FSG) but maintained it at an acceptable level. The acceptance by farmers of TST strategies, and their implementation, may require a high level of input and education to the farming community.

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32

Pham, Xuan Minh. "Large shareholding networks and equity raising: Evidence from bank-holding companies." Thesis, Queensland University of Technology, 2021. https://eprints.qut.edu.au/208013/1/Xuan%20Minh_Pham_Thesis.pdf.

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This thesis examines the information network created by multiple large shareholders around seasoned equity offerings (SEOs) of bank-holding companies (BHCs). Analyzing the network using social network analysis (SNA), I find the abnormal stock returns around SEO announcements are related to large shareholding network centrality, suggesting that multiple large shareholders are able to capitalize on their position in the network to mitigate agency cost and information asymmetries. The network also creates a spillover effect by transmitting information about the SEO announcements from issuers to other non-issuers belonging to the same large shareholder network.

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Johnson, Luanne PhD. "The Behavioral Ecology and Population Characteristics of Striped Skunks Inhabiting Piper Plover Nesting Beaches on the Island of Martha's Vineyard, Massachusetts." Antioch University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=antioch1463581942.

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34

Scohier, Alexandra. "Impact d'une mise en defens temporaire de prairies permanentes durant le pic de floraison : sélection alimentaire des brebis, diversité floristique et entomologique (Lepidoptera, Bombidae, Carabidae) des couverts." Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2011. http://tel.archives-ouvertes.fr/tel-00708561.

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L'érosion de la biodiversité prairiale est devenue une préoccupation majeure à l'échelle Européenne. Le pâturage ovin est supposé avoir un impact négatif sur la diversité prairiale, en raison de leur forte sélectivité pour les dicotylédones, indispensables aux insectes pollinisateurs. Comparés aux bovins, les ovins structurent peu les couverts et créent également moins de niches écologiques contrastées. L'objectif de cette thèse était de tester la faisabilité, et les bénéfices en pâturage ovin, d'une conduite en rotation dans laquelle une sous-parcelle est temporairement exclue du pâturage au moment du pic de floraison. Les effets de cette conduite ont été comparés à ceux d'un pâturage continu au même chargement. Au delà des indicateurs directs de performances zootechniques et de biodiversité (plantes, papillons, bourdons et carabes), nous avons analysé la sélection alimentaire des brebis dans les deux modes de conduite. Nous avons aussi cherché à appréhender comment la race et la fertilité du milieu pouvaient moduler la faisabilité d'un tel pâturage tournant et son intérêt vis-à-vis de la préservation de la biodiversité. Indépendamment de leur race, les brebis ont présenté une sélection alimentaire accrue vis-à-vis des dicotylédones dans les parcelles pâturées en rotation, qui a rapidement entraîné une diminution de leur richesse floristique en comparaison des parcelles pâturées en continu. L'augmentation de l'intensité de floraison des sous parcelles temporairement exclues de la rotation a favorisé les bourdons, probablement en raison de l'augmentation de la ressource en pollen et en nectar. En revanche, ce mode de gestion n'a pas permis d'augmenter la densité ni la richesse spécifique des papillons et des carabes. Le bénéfice d'une mise en défens temporaire d'une partie des parcelles semble donc moindre qu'en pâturage bovin. Définir les dates de mises en défens par rapport à la floraison d'espèces indicatrices, moduler la durée de la mise en défens en fonction de la pousse de printemps, et prolonger l'exclusion de certaines parcelles en automne et en hiver sont autant de pistes qu'il nous reste à explorer, afin de déterminer les conditions d'application optimale d'une telle conduite.

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Clay, Ryan Gered, and 賴思傑. "Cross-Seasonal Habitat Selection of Altitudinal Migratory Birds in Taiwan." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/245ya4.

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碩士
國立東華大學
自然資源與環境學系
100
Understanding the reactions of avian species to altered habitat is imperative for effective management and conservation of biodiversity. The altitudinal migration in Taiwan provides an excellent object for studying the adaptability of migratory birds because several foraging guilds exhibit migratory behavior and there is higher likelihood for opportunistic change in the types of habitat used during different seasons. This study used line transect surveys to investigate habitat use and preferences among six altitudinal migratory birds. Count surveys were conducted twice per month between 1000 and 2500 meters elevation in the mountains of Taroko National Park in northeastern Taiwan. Observations took place over three seasons before migration (December 2010 to February 2011), after migration (April to June 2011), and during the recruitment of young to the population (July to September 2011). Seasonal variation in the distribution and abundance of study species was likely influenced by migration, recruitment of young, and changes in flocking behavior. However, the habitat preferences of all six species stayed the same throughout the year. Taiwan Yuhinas (Yuhina brunneiceps) preferred forest habitats over orchard habitats. Grey-cheeked Fulvettas (Alcippe morrisonia) used forests around 1500m, particularly in winter. The Red-headed Tit (Aegithalos concinnus) and Collared Bush Robin (Erithacus (or Tarsiger) johnstoniae) used all habitat types observed through the year. Green-backed Tits (Parus monticolus) used edge habitats more often at high elevations than low elevations (p < 0.003), as did Taiwan Sibias (Heterophasia auricularis), but both species used forests more often than orchards.

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Leech, Heather. "Seasonal Habitat Selection by Resident and Translocated Caribou in Relation to Cougar Predation Risk." Thesis, 2015. http://hdl.handle.net/1828/5974.

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Mountain caribou, an arboreal lichen-feeding ecotype of woodland caribou (Rangifer tarandus caribou), have been extirpated from much of their historic range. Mountain caribou are federally listed as Endangered by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) and red-listed by the BC government. Habitat loss and fragmentation of old growth forest is the ultimate cause for population declines. Yet, predation, linked to apparent competition, is the proximate cause for high rates of mortality. One of the most imperiled populations resides in the Purcell Mountains of BC, which was experimentally augmented in 2012 with 19 northern caribou from northern BC. The caribou-predator literature predominantly focuses on the relationship between caribou and wolves (Canis lupus) in northern caribou populations. However, cougars (Puma concolor) have been identified as a major predator of Purcells-South (PS) caribou, yet caribou-cougar interactions remain largely unstudied. I evaluated cougar predation risk in space and time on resident and translocated caribou in the Purcell Mountains. To do so, I determined biologically relevant seasons for resident, donor (i.e. not translocated) and translocated caribou, and cougars. I then used these seasons to investigate seasonal patterns of movement and habitat use between the three groups of caribou and cougars. Next I used resource selection functions (RSFs) to estimate habitat based seasonal variation in predation risk. I used these RSFs to compare the seasonal habitat selection and risk to cougar predation between resident and translocated caribou. Five resident caribou seasons and two cougar seasons were defined. Translocated caribou displayed inconsistent movement behavior with no clear seasonal pattern. Resident caribou remained at high elevations year-round and selected for low risk cougar habitat during the calving season at the home range scale and year-round at the landscape scale. Translocated caribou displayed risky behaviour throughout the study period by traveling to mid to low elevations and habitats selected by cougars. Translocated caribou displayed the same general pattern of elevational movement as their northern conspecifics, spending the majority of their time at lower elevations than resident caribou. Of the 19 translocated caribou, 17 (89%) died during the study, six of which were preyed upon by cougars, two by wolves, and the remainder due to accidents or unknown causes. In summary, translocated caribou did not adopt the predator avoidance or habitat selection strategies of resident caribou. I recommend that future efforts to augment small caribou populations use donor caribou experienced with similar predators and that possess comparable seasonal habitat use to the recipient population. However, because most suitable donor populations are declining, a soft-release of captive-reared mountain caribou might be the best option for mountain caribou recovery efforts.
Graduate
0366
0329

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Morehouse, Andrea. "Venison to beef and deviance from truth: biotelemetry for detecting seasonal wolf prey selection in Alberta." Master's thesis, 2010. http://hdl.handle.net/10048/1243.

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An abrupt interface between mountains and prairies in southwestern Alberta means wilderness areas and carnivore populations overlap cattle grazing lands. Consequently, there is concern about the effects of large carnivores, especially wolves, on livestock. I used GPS clusters and scat samples to determine year-round wolf diets in this region. Both methods indicated a significant seasonal shift in wolf diets from wild prey during the non-grazing season to cattle in the grazing season. The GPS cluster method effectively identified wolf kills but this method relies on telemetry with high accuracy and precision. In southwestern Alberta, Argos satellite radicollars have been used extensively by wildlife managers. I compare how differences in precision between GPS and Argos technologies affect the estimation of habitat-selection models. Differences in accuracy and precision can lead to erroneous conclusions about animal selection of habitat.
Ecology

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38

Wu, Chi-Pin, and 吳啟斌. "Seasonal Patterns in Group, Population Composition, Daily Activity Cycle and Habitat Selection of Blue Sheep (Pseudois nayaur) in Helanshan." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/01408248287300410711.

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碩士
國立中山大學
生物科學系研究所
92
The blue sheep (Pseudious nayaur) is the major large-size herbivores in Helanshan. During studying, the blue sheep mean group size were 4.2∼7.1, with smaller group size than in other ranges. Mixed groups were usually bigger than male and female groups. Sex ratio the most close was 1:1.08 (♀:♂) in winter, and other samples still favored males except for fall. The highest ratio of adult female to young was 1:0.78 in summer. In daily activity cycle, blue sheep usually moved and fed in morning and evening, but rested during noon. In summer, animals started active earlier and ended latter than in winter, but had more short active time. From summer to fall, the blue sheep mostly used the edge of forest and used forest least in altitude 2200m. But in altitude 1700m, blue sheep used grassland more than frequently bush and fountain.

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39

"Seasonal variations in habitat availability, habitat selection, and movement patterns of Myocastor coypus on a subtropical freshwater floating marsh." Tulane University, 2006.

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I employed a combination of vegetative sampling, GIS mapping, and radiotelemetry to examine habitat availability, habitat selection, and movement patterns of the invasive nutria on a freshwater floating marsh at Jean Lafitte National Historical Park and Preserve (JLNHPP) in southeastern Louisiana. I found that the floating marsh is both spatially and temporally dynamic at the plant species level. Nutria at this study site had larger home ranges than reported for most other nutria studies. This finding could be attributed to a low to moderate population density, patchy resource distribution, and/or improved telemetry techniques. I evaluated habitat selection at three different scales, or orders of selection; the home range, the location point habitat type, and the individual plant species composition at location points. Nutria did not select habitat at the home range or habitat type level; i.e. they did not select based upon broad-scale habitat characteristics or by dominant plant species. Across all seasons, nutria selected habitats that were significantly different from those available to them at the plant species level. Male and female nutria did not differ significantly in their overall patterns of habitat use and movement. These findings suggest that nutria occupy a spatially and temporally dynamic habitat and that their utilization of this habitat depends heavily upon the individual plant species present at a specific locale
acase@tulane.edu

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40

Edde, Peter Ayodele. "Studies with the aggregation pheromones of Ryhzopertha dominica (Coleoptera: Bostrichidae) habitat affinities, seasonal flight activity, and pheromone-mediated host selection behavior /." 2005. http://digital.library.okstate.edu/etd/umi-okstate-1558.pdf.

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41

Ellis, David John. "Seasonal regulation of the circadian rhythms of behavioural temperature selection and locomotor activity in Australian sleepy lizards (Tiliqua rugosa, gray; reptilia: scincidae)." 2010. http://hdl.handle.net/2440/60035.

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This research project examined the role of environmental time cues and circadian rhythms in mediating seasonal adjustments in the body temperature and locomotoractivity patterns in the Australian sleepy lizard, Tiliqua rugosa (Gray 1827). The first component of this study investigated whether daily rhythms of behavioural thermoregulation and locomotor activity that T. rugosa displays in the field are endogenous circadian rhythms. In each season, there was significant variation in each of these rhythms in lizards released on laboratory thermal gradients under prevailing light-dark (LD) cycles. Both rhythms persisted when lizards were released in constant darkness (DD) and exhibited the same free-running period suggesting a single circadian pacemaker drives both rhythms. The first component of this study revealed that seasonal changes in the expression of daily behavioural thermoregulatory and locomotor activity rhythms are mediated by the circadian system in T. rugosa. The second component of this project comprised three experiments that determined the relative importance of 24 h LD and temperature cycles (TCs) in entraining the locomotor activity rhythm. In the first experiment, lizards were held under LD 12:12 and were subjected to either a TC of 33:15C in phase with the LD cycle or a reversed TC. Following LD 12:12, lizards were maintained under the same TCs but were subjected to DD. Activity was restricted to the thermophase in LD irrespective of the lighting regime and during the period of DD that followed, suggesting entrainment by the TC. In the second experiment, lizards were held under LD 12.5:11.5 and were subjected to one of three treatments; (1) constant 30C, (2) normal TC (30:20C), or (3) reversed TC. Following LD, all lizards were subjected to DD and constant 30C. Post-entrainment free-run records revealed that LD cycles and TCs both entrain locomotor activity rhythms of T. rugosa. Although there was large variation in the phasing of the rhythm in relation to the LD cycle in reversed TC lizards, TCs presented in phase with the LD cycle most accurately synchronised the rhythm to the photocycle. In the third experiment, lizards were held in DD at constant 30C before being subjected to a further period of DD and one of four treatments; (1) normal TC (06:00 h to 18:00 h thermophase), (2) delayed TC (12:00 h to 00:00 h thermophase), (3) advanced TC (00:00 h to 12:00 h thermophase) or (4) control (no TC, constant 30C). While control lizards continued to free-run in DD at constant temperature, locomotor rhythms of lizards subjected to TCs rapidly entrained to TCs irrespective of whether TCs were phase advanced or delayed by 6 h. The results of this experiment excluded the possibility that masking effects were responsible for locomotor responses of lizards to TCs. This study demonstrated that seasonal changes in the expression of this species‟ daily behavioural thermoregulatory and locomotor rhythms are mediated by a circadian system that is sensitive to both light and temperature. The sensitivity of the circadian system to temperature, in particular, may allow T. rugosa to restrict its activity to times of the year that are thermally favourable.
http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1521959
Thesis(Ph.D.)-- University of Adelaide, School of Medical Sciences, 2010

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42

Ellis, David John. "Seasonal regulation of the circadian rhythms of behavioural temperature selection and locomotor activity in Australian sleepy lizards (Tiliqua rugosa, gray; reptilia: scincidae)." Thesis, 2010. http://hdl.handle.net/2440/60035.

Full text

Abstract:

This research project examined the role of environmental time cues and circadian rhythms in mediating seasonal adjustments in the body temperature and locomotoractivity patterns in the Australian sleepy lizard, Tiliqua rugosa (Gray 1827). The first component of this study investigated whether daily rhythms of behavioural thermoregulation and locomotor activity that T. rugosa displays in the field are endogenous circadian rhythms. In each season, there was significant variation in each of these rhythms in lizards released on laboratory thermal gradients under prevailing light-dark (LD) cycles. Both rhythms persisted when lizards were released in constant darkness (DD) and exhibited the same free-running period suggesting a single circadian pacemaker drives both rhythms. The first component of this study revealed that seasonal changes in the expression of daily behavioural thermoregulatory and locomotor activity rhythms are mediated by the circadian system in T. rugosa. The second component of this project comprised three experiments that determined the relative importance of 24 h LD and temperature cycles (TCs) in entraining the locomotor activity rhythm. In the first experiment, lizards were held under LD 12:12 and were subjected to either a TC of 33:15C in phase with the LD cycle or a reversed TC. Following LD 12:12, lizards were maintained under the same TCs but were subjected to DD. Activity was restricted to the thermophase in LD irrespective of the lighting regime and during the period of DD that followed, suggesting entrainment by the TC. In the second experiment, lizards were held under LD 12.5:11.5 and were subjected to one of three treatments; (1) constant 30C, (2) normal TC (30:20C), or (3) reversed TC. Following LD, all lizards were subjected to DD and constant 30C. Post-entrainment free-run records revealed that LD cycles and TCs both entrain locomotor activity rhythms of T. rugosa. Although there was large variation in the phasing of the rhythm in relation to the LD cycle in reversed TC lizards, TCs presented in phase with the LD cycle most accurately synchronised the rhythm to the photocycle. In the third experiment, lizards were held in DD at constant 30C before being subjected to a further period of DD and one of four treatments; (1) normal TC (06:00 h to 18:00 h thermophase), (2) delayed TC (12:00 h to 00:00 h thermophase), (3) advanced TC (00:00 h to 12:00 h thermophase) or (4) control (no TC, constant 30C). While control lizards continued to free-run in DD at constant temperature, locomotor rhythms of lizards subjected to TCs rapidly entrained to TCs irrespective of whether TCs were phase advanced or delayed by 6 h. The results of this experiment excluded the possibility that masking effects were responsible for locomotor responses of lizards to TCs. This study demonstrated that seasonal changes in the expression of this species‟ daily behavioural thermoregulatory and locomotor rhythms are mediated by a circadian system that is sensitive to both light and temperature. The sensitivity of the circadian system to temperature, in particular, may allow T. rugosa to restrict its activity to times of the year that are thermally favourable.
Thesis(Ph.D.)-- University of Adelaide, School of Medical Sciences, 2010

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Penfold, Jessica. "Using approximate Bayesian computation and machine learning model selection techniques to understand the impact of climate on seasonal influenza-like illness in Australia." Thesis, 2019. http://hdl.handle.net/2440/121360.

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Influenza-like illness exhibits a strong seasonal cycle in temperate climates, with a peak of varying intensity appearing each winter. However, the driving force of this seasonal cycle remains poorly understood. We develop stochastic epidemic models and a model selection framework to understand influenza-like illness seasonality, with the basic reproduction number R0 being dependent on climate. We test four Functional Forms of transmissibility based on three different climate variables and select the best Functional Form for climate-dependent transmissibility via modern Bayesian machine learning model selection methods. By analysing a unique dataset comprising ten years of General Practitioner-reported influenza-like illness surveillance data from Adelaide, Brisbane, Perth and Sydney, Australia, we explore the relationship between influenza-like illness transmission and weather across Mediterranean and subtropical climate zones. We find that absolute humidity has the strongest impact on seasonal influenza-like illness, with two different Functional Forms both based on absolute humidity best describing influenza-like illness in Mediterranean and subtropical climates. Finally, we consider the problem of forecasting the timing of peak influenza-like illness using ensemble modelling techniques. We employ two score metrics and four techniques for calculating ensemble weights in a prototype ensemble forecasting framework. By implementing this method to predict the peak week of influenza-like illness in 2014 in each of the four different locations, we find that forecasting peak week from the start of the year is a challenging exercise providing mixed conclusions on the best training methods, with two approaches – traditional and prototype – producing comparable results. We find again that absolute humidity appears to be a strong factor in the seasonality of influenza-like illness, and find that random forests are a useful tool in informing ensemble forecast weights.
Thesis (MPhil) -- University of Adelaide, School of Mathematical Sciences, 2019

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Sanders, David M. "Survey of mosquitoes in high and low incidence areas for West Nile virus in Shelby County, Tennessee with assessment of parity rates, host selection, and seasonal abundance /." 2005. http://etd.utk.edu/2005/SandersDavid.pdf.

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Thesis (M.S.) -- University of Tennessee, Knoxville, 2005.
Title from title page screen (viewed on July 13, 2005). Thesis advisor: Reid R. Gerhardt. Document formatted into pages (xii, 77 p. : ill. (some col.), maps (some col.)). Vita. Includes bibliographical references (p. 67-76).

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Barua, Kamini Kusum. "Diversity and Habitat Selection of Papilionidae in a Protected Forest Reserve in Assam, Northeast India." Doctoral thesis, 2008. http://hdl.handle.net/11858/00-1735-0000-000D-F116-2.

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Lee, Cheng Dal, and 李政達. "Adverse Selection Risk、Stock Bid-Ask Spread and Seasoned Equity." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/88314371005042616538.

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楊彭琳. "Enterprise Resource Planning Selection Mechanism - A Case of Season Arts Preschool." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/18585964825810647552.

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碩士
逢甲大學
經營管理碩士在職專班
104
Through the globalization of the economic system and the intense competition in the market, corporates can only increase long term business benefit by improving hardwares and softwares to become more tech savvy. Nowadays, corporates are eagerly adapting ERP, hoping to reach its goal by integrating various kinds of resources and enhance its competitiveness through information technology. However, due to the constant change of the economic environment, scale of enterprises and business models, the original ERP system may not be capable to maintain corporate’s competitiveness or obtain profit through time. Therefore, enterprises may have to replace the old ERP system with a newer one. Currently, more and more suppliers are providing ERP systems, yet, the country is seriously lack of selection standards. Since building a ERP system costs a massive amount of resource and money, a good selection criteria before conducting or changing the ERP system is especially significant. To senior managers, it really is challenging to evaluate a suitable ERP system. This study aims to confirm and analyze the purpose, method, factors of selection criteria, steps of conducting before adapting or changing a ERP system by doing a questionnaire survey. Results of the study will serve as a future reference for corporates before conducting or changing a ERP system. According to the results, medium-sized and small sized enterprises often adopt the method of IT outsourcing, partly of it customized. The most critical selection factor a corporate first conducts or changes its ERP system is whether a system supplier can provide sustainable service and its ability in various areas. The main reason of failing when facing issues is using departments not clearly express its requirements. After changing the ERP system, the additional functions and information provides decision-makers a strategy reference. Moreover, the ease of operation simplifies the work flow, decreases operation costs, and improves work efficiency. In conclusion, it effectively controls the corporate’s operation. Keywords: Enterprise resource planning, Preschool

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Hoffmann, Leo. "Introduction and Selection of Photoperiod Sensitive Sorghum Genotypes for Agronomic Fitness and Biomass Composition." Thesis, 2012. http://hdl.handle.net/1969.1/ETD-TAMU-2012-08-11802.

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In 2007, U.S. Congress created the "Energy Independence and Security Act" with primary goals focused on increasing the knowledge in production of renewable fuels, increasing the percentages of renewable fuels in the transportation sector and decreasing the emissions of greenhouse gases from fossil fuel sources. To achieve these goals, many species have been pointed as sources of feedstock for the biofuel industry. Photoperiod sensitive (PS) biomass sorghum for the lignocellusosic based conversion is one. In this study, three main objectives were addressed regarding the relative performance for biomass yield and biomass composition of PS biomass sorghum. First, genetic and environmental variation effects on the biomass yield and biomass composition, and usefulness of pre-classification of genotypes by biomass lignin content were evaluated. On the set of genotypes and locations tested, the environmental effect had the largest influence on the biomass composition, yield and its components. Although smaller, the genetic variation effect was significant for most of the traits, some traits had significant genotype by environment GXE interaction. The pre-classification of genotypes according to lignin content proved to be an efficient system of separating genotypes as groups, but failed to be efficient in separating on the entries bases. Assessment of growth patterns for biomass yield and composition, characterized photoperiod sensitive sorghum as capable of producing a harvestable crop as soon as 4 months, but variations in the concentration of constituents and moisture percentage, pointed to a harvest window that can be extended up to the 7th month after planting. Genetic variation was observed in this trail for most agronomic and composition traits, but a strong environmental effect was also observed. Lastly, the influence of three diverse cytoplasm male sterility (CMS) systems in biomass sorghum hybrids was assessed. The presence of A1, A2 or A3 CMS in the hybrids tested in this study had no influence on the biomass yield performance or in the biomass composition. Therefore, any of the CMS systems can be used in the production of biomass sorghum hybrid seed. Also, in this trial the environmental effects were significant and strong for most traits evaluated.

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Jhala, Shesh. "Nocturnal Movements and Distributions of Bobcats, Coyotes and Raccoons during Quail Nesting Season." Thesis, 2013. http://hdl.handle.net/1969.1/149435.

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Northern bobwhites (Colinus virginianus) are a valued game species that have seen massive population declines in the last few decades. This decline has been attributed to many factors including predation, the topic of this study. I examined the habitat selection, nocturnal movement and potential rate of encounter with quail nesting locations by coyotes (Canis latrans), bobcats (Lynx rufus), and raccoons (Procyon lotor) at the Rolling Plains Quail Research Ranch, a private 19 km2 ranch in the Rolling Plains ecoregion of west Texas. My study had 2 objectives: (1) to compare the habitat use of mesopredators in the Rolling Plains to the nesting habitat of bobwhites, and (2) to characterize the nocturnal paths of these mesopredators and measure their overlap with quail nesting locations. I placed GPS collars on 4 bobcats, 7 coyotes and 11 raccoons during the quail nesting seasons of 2009-2011. I used the chi-square test as well as a modified version of the Ivlev’s Electivity Index (1961) to calculate habitat selectivity. I also measured the proximity of the mesopredators and quail nesting locations to roads, water and quail feeders on the ranch. I used fractal analysis to calculate length and tortuosity of nocturnal paths and assessed potential risk to quail nests by determining the intersection rates of mesopredator paths with quail nesting locations. I found that a large difference existed in selectivity of habitat between bobwhite nesting locations and the bobcats and raccoons. Bobwhites selected for the upland grasslands and shrubs and against rocky ridges. Bobcats selected for riparian zones, while raccoons selected for both riparian zones and rocky ridges, neither of which were selected for by nesting quail. Bobcats and male raccoons additionally showed a propensity for road travel, which quail often nested close to. Coyotes selected strongly for grasslands, utilized their home ranges comprehensively and showed a preference for road usage, and thus had the greatest potential encounter rate with quail nest sites. However, coyotes also showed the most linear and direct movement pattern, potentially reducing their efficiency in finding quail nests. This study indicates that coyotes potentially present the largest threat to the nests of quail and female raccoons the least. Management decisions such as the levels of management needed for the 3 species of mesopredators are discussed.

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(6620417), Jada S. Powlen. "Strategies for Reducing Supplemental Irrigation of Cool-Season Lawns through Species Selection, Mowing Practices, and Irrigation Scheduling." Thesis, 2019.

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Water resources for outdoor areas, such as lawns and landscapes, continues to become limited in many urban areas, especially in times of acute drought stress. Lawn species selection and cultural practices, such as mowing height, can strongly influence overall seasonal water needs. While previous research has reported various lawn species water use rates and differences in the ability of some cultivars to maintain green coverage during acute drought stress, little is known regarding the irrigation requirements of cool-season lawn species when using a deficit irrigation strategy based on a green coverage target threshold (e.g. 60-80% green) approach. Two greenhouse studies were conducted to screen various candidate species and seed mixtures in a sandy media. The highest water use and worst appearance/green coverage was associated with an inexpensive commercial lawn mixture; and the lowest water use and best appearance was generally associated with improved Kentucky bluegrass (Poa pratensis L.: KBG) cultivars. Field studies were conducted to quantify the irrigation requirements of drought susceptible (DS) and improved, drought tolerant (DT) KBG and tall fescue [Schedonorus arundinaceus (Schreb.): TF] cultivars, blends and mixtures at two mowing heights (5.1 or 8.9 cm). Results from a 74-day field study using a deficit irrigation replacement approach with a 70% green coverage threshold (GCT₇₀) irrigation trigger, demonstrated water savings of approximately 73 to 78% when using a DT TF (60.3 mm) as compared to 100% evapotranspiration (ET_o) replacement (223.4 mm) and a conventional lawn irrigation approach (268.5 mm), respectively. The time to reach the GCT₇₀ generally ranked: TF=TF:KBG mixture>KBG and ranged from 18.0 days for DS ‘Right’ KBG and 52.5 days for DT ‘RainDance’ TF. Among TF and KBG cultivars using the GCT₇₀irrigation approach, DT TF required 35 to 68% less supplemental irrigation compared to DT and DS KBG cultivars (92.1 vs. 187.3 mm), respectively. Within KBG cultivars, the DT ‘Desert Moon’ required one-half the irrigation of DS Right (92.1 vs. 187.3 mm), while there were no differences among TF cultivars for irrigation needs. Mowing height did not affect KBG irrigation needs, but TF at 5.1 cm showed increased visual quality and green coverage, and significantly reduced irrigation requirements. Field research also compared species mixtures and blends using DS and DT KBG and TF to determine the amount of a DT species/cultivar that would enhance drought performance with ratios ranging from 25-100% DT as well as 90:10 TF:KBG mixtures. The quantity of a DT KBG in a blend, and DT TF in a TF:KBG mixture reduced irrigation needs, whereas the drought rating of the KBG cultivar in a TF:KBG mixture had no significant effect. In summary, these studies continue to demonstrate that significant supplemental lawn irrigation savings can be achieved by the selection of superior DT species and cultivars combined with a deficit irrigation replacement approach compared to other cool-season species and conventional irrigation practices.

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Dissertations / Theses on the topic 'Seasonal Selection'

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