Dissertations / Theses: 'Sympatric'

1

McDonald, Patrick T. "Habitat affiliations of sympatric carnivores in southern Illinois /." Available to subscribers only, 2006. http://proquest.umi.com/pqdweb?did=1203552421&sid=1&Fmt=2&clientId=1509&RQT=309&VName=PQD.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Elmhirst, Toby. "Symmetry and emergence in polymorphism and sympatric speciation." Thesis, University of Warwick, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.275232.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Zablotski, Yury [Verfasser]. "Optimality and trait based approaches to sympatric speciation and sympatric co-evolution of predator and prey traits in marine plankton / Yury Zablotski." Kiel : Universitätsbibliothek Kiel, 2014. http://d-nb.info/105432820X/34.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Fortin, Jennifer Kay. "Niche separation amongst sympatric ursids relative to salmon use." Online access for everyone, 2006. http://www.dissertations.wsu.edu/Thesis/Summer2006/j%5Ffortin%5F053106.pdf.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

Bekker, Kent A. "Comparative Growth and Demographics of Two Sympatric Natricine Snakes." Bowling Green State University / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1187361243.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Didyk, A. S. "The helminth communities of five sympatric species of nearctic shorebirds." Thesis, University of New Brunswick, 1999. http://hdl.handle.net/1882/851.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Didyk, Andy Stephan. "The helminth communities of five sympatric species of nearctic shorebirds." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ54590.pdf.

Full text

APA, Harvard, Vancouver, ISO, and other styles

8

Loveridge, Andrew John. "Behavioural-ecology and rabies transmission in sympatric southern African jackals." Thesis, University of Oxford, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.325375.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Smith, Herbie. "New models of sympatric speciation through sexual selection in animals." Thesis, University of Southampton, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310754.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

Carrière, Suzanne. "Habitat selection by sympatric black ducks and mallards in Abitibi, Quebec." Thesis, McGill University, 1991. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=59984.

Full text

Abstract:

Habitat use by sympatric black ducks (Anas rubripes) and mallards (A platyrhynchos) was studied in Abitibi, Quebec during May-August 1988 and 1989.
Black duck broods preferred emergent and shrub-rich areas in both years. Mallard broods' habitat use differed from 1988 to 1989 (from emergent to shrub-emergent areas) when average water levels were higher. Diversity of habitats seems more important to rearing black ducks than to mallards. Rearing mallards seem to modify their use of habitats according to changing habitat availability. Daily survival rates differed only slightly between "species".
Telemetry was used to study wetland use by six mallard and three black duck non-breeding females. Swamps were preferred whereas ericaceous shrub wetlands were avoided by both "species". Beaver (Castor canadensis) ponds were extensively used during the moulting period. Home ranges averaged 302.7 ha for black ducks and 201.2 ha for mallards.

APA, Harvard, Vancouver, ISO, and other styles

11

Ojala, Jeffrey Veikko. "Invertebrate phenology and prey selection of three sympatric species of Salmonids." Connect to this title online, 2008. http://scholarworks.umass.edu/theses/97/.

Full text

APA, Harvard, Vancouver, ISO, and other styles

12

Mantilla-Beniers, Natalia Bárbara. "Spatio-temporal dynamics of sympatric childhood diseases in the 20th century." Thesis, University of Cambridge, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.614877.

Full text

APA, Harvard, Vancouver, ISO, and other styles

13

Young, Kevin V. "Comparative Ecology of Narrowly Sympatric Horned Lizards Under Variable Climatic Conditions." DigitalCommons@USU, 2010. https://digitalcommons.usu.edu/etd/647.

Full text

Abstract:

We studied the Flat-tailed Horned Lizard, Phrynosoma mcallii, and the Sonoran Horned Lizard, P. goodei, in an area of narrow sympatry near Yuma, Arizona, and found they overlapped broadly in use of available food resources, body size, and growth rates. We compared diet (Chapter 2), growth and reproduction (Chapter 3), and survivorship (Chapter 4) of P. mcallii and P. goodei during two years of drought followed by a year of higher-than-average rainfall. We predicted that P. mcallii would be more tolerant of drought conditions than its congener, since P. mcalliiis found only in an extremely arid region while P. goodei is part of a more northerly-clade and that P. goodei is excluded from the sandy habitat of P. mcallii due largely to the paucity of rainfall and the lack of moisture-holding ability of the sand. During the extended period of drought food became limited, horned lizards lost mass, and there was less growth and reproduction. While both species showed strong differences between dry and wet years, the within-year differences between species were generally small. When resources were abundant we witnessed rapid growth for both P. mcallii and P. goodei and a much higher rate of reproduction. While both species showed similar growth patterns, P. mcallii had a smaller adult body size, larger hatchling size, and seasonally-delayed reproduction compared to P. goodei; differences we propose are adaptations for frequent periods of drought, but which may be disadvantageous in years of abundant resources. We used mark-recapture analysis to derive estimates of detection probability and survival rates. Contrary to prediction, survival rate estimates were higher for P. goodei than for P. mcallii, and higher in dry years than in wet years. However, decreased probability of detection and increased emigration in the wet year confounded survival rate estimates. We also reviewed the conservation and management of P. mcallii, a species of conservation concern (Chapter 5). We proposed using fine-scale scat surveys rather than mark-recapture surveys for the long-term monitoring of P. mcallii.

APA, Harvard, Vancouver, ISO, and other styles

14

Thomas, Alicia Jessica. "Factors affecting the emergence times of seven sympatric insectivorous bat species." Master's thesis, University of Cape Town, 2011. http://hdl.handle.net/11427/12672.

Full text

Abstract:

Includes bibliographical references (leaves 68-84).
The onset of activity in animals restricted to being active for only part of the day, is one of the most fundamental aspects of their biology. Onset of activity is likely subject to several factors including presence/absence of predators and the vagaries of environmental conditions at the time of emergence. The aim of my study was to test several hypotheses accounting for differing emergence times amongst sympatric insectivorous bat species.

APA, Harvard, Vancouver, ISO, and other styles

15

Puddicombe, Robert D. "An investigation of sympatric speciation in diploid organisms by computer simulation." Thesis, University of Surrey, 2015. http://epubs.surrey.ac.uk/809540/.

Full text

Abstract:

This thesis proposes that sympatric speciation can arise, in certain circumstances, in diploid sexually-reproducing organisms by mechanisms other than autopolyploidy. This proposition is verified by a series of computer simulations of the natural, biological, genetic processes of reproduction. The research is essentially a series of logical experiments using a computer simulation of natural genetic mechanisms of reproduction. In this methodology there is no direct comparison with biological data but the simulation follows, as closely as possible, natural genetic mechanisms of reproduction. The selected modelling method uses a framework derived from Penna 1995 which represents individual genes as binary digits on digital chromosomes and incorporates randomised simulations of recombination, copying-errors, meiosis and zygote production. The literature search identified some difficulties with defining species but a choice was made to use the `Biological Species Concept', which relies on reproductive isolation as evidence of speciation. Sympatric speciation by recombinational processes is said by some to be rare or unknown in nature, but sympatric speciation by autopolyploidy is said to be common in plants. The simulations reported here exclude the possibility of autopolyploidy and rely only on recombination and mutation processes. The model described by Penna 1995 was shown to be inadequate for representing multiple species. It was therefore modified to allow more genetic variability but to restrict mating to compatible phenotypes and to allow assortative mating. Simulations demonstrated that sympatric speciation can occur in scenarios based on the Dobzhansky-Muller model and that these processes can be facilitated by the intervention of selective predators. Another form of sympatric speciation was also detected where paired, dominant and recessive alleles lead to incompatible phenotypes. No reference has been found in the literature to modelling the Dobzhansky-Muller mechanism, except for Gavrilets 1997 who describes a mathematical analysis rather than a simulation.

APA, Harvard, Vancouver, ISO, and other styles

16

Hatchett, William. "The road toward sympatric speciation in whitefish. : The effects of divergent selection on European whitefish (Coregonus lavaretus) size and behavior, and effects on zooplankton communities." Thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-110741.

Full text

Abstract:

For almost every organism there are large gaps in our knowledge about the processes that leads to speciation. The changes an organism undergoes before divergence has occurred have remained a mystery, as it is difficult to say whether or not a species is going to diverge and when. To investigate this unknown the European whitefish (Coregonus lavaretus) and the northern pike (Esox lucius) were studied, as they produce a repeatable and predictable pattern of speciation in sympatry. To investigate the changes in phenotypes and behaviour in whitefish that precedes divergence, two lake populations were examined, Gräsvattnet and Ringsjön. Gräsvattnet was used as a control, with a population of whitefish but an absence of pike, whereas Ringsjön has a population of whitefish that invaded from Gräsvattnet and a pike population. The presence of pike presumably exerts divergent selection on the whitefish population. Fish and zooplankton were surveyed in both lakes from 1970 to the present day, which allows us to compare how whitefish populations and their resources change in the presence and absence of pike. The results found in Ringsjön show; (1) a change in habitat use, (2) a change in diet from pelagic to benthic, (3) an increase in the relationship between individual body size and diet and (4) a decrease in average size over the course of the study. (1)The presence of pike is believed to have forced the whitefish into the pelagic which could be seen in the result, with an increase in individuals caught in the pelagic. (2) The change in diet is thought to be caused by a resource competition created by individuals being forced to use the pelagic. Although insignificant this led to an overall reduction in zooplankton abundance by almost 40% which could have intensified competition. The resource competition could then have been intensified further by the change in composition of zooplankton relative abundance. (3) The increase in relationship between individual body size and diet is thought to increase due to the resource competition between smaller and larger individuals in the pelagic. Smaller individuals are better competitors than larger individuals for pelagic resource which could have led to the larger individuals switching to a more benthic diet. (4) The decrease in average size is thought to be caused by negative selection for larger individuals. Larger individuals have switched to a more benthic diet, and although the individuals are larger they still face the risk of predation in the littoral zone as they have not outgrown the gape size of the pike. This could have led to the average size reduction that may be the first steps in speciation, and ultimately leading to the divergence of two morphs by sympatric speciation in Ringsjön. In Gräsvattnet over the course of the study there were few and small changes in whitefish size, zooplankton relative abundance in the diet and in the environment. The results in Gräsvattnet could however suggest resource competition for benthic resources. Although resource competition is thought to be an important factor in the speciation of whitefish, without predation pressure no speciation occurs. This result could suggest the importance of predation pressure in the speciation of whitefish.

APA, Harvard, Vancouver, ISO, and other styles

17

Moeser, Andrew A. "Genetic analyses of sympatric cryptic species in the Neotropical catfish, Pimelodella chagresi." Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=82294.

Full text

Abstract:

I used microsatellite markers to assess reproductive isolation between cryptic, sympatric lineages of a freshwater catfish (Pimelodella chagresi ). These are "cryptic" lineages because they cannot be distinguished visually on the basis of morphological characters, and currently they are recognized as a single species. Previous analyses utilizing mitochondrial DNA (mtDNA) indicated that two highly divergent lineages are present in lower Central America, and that these lineages are the result of independent colonization events from South American source populations. I isolated eight dinucleotide repeats from P. chagresi and designed primers to amplify these microsatellite loci. I sampled fishes from four Panamanian watersheds. The congruence of microsatellite data with mtDNA indicated that these taxa are reproductively isolated and should be considered as separate species despite the lack of morphological differentiation. Both lineages exhibit a high degree of divergence among populations inhabiting isolated freshwater drainages, but the lineages differ in their intra-watershed population structure.

APA, Harvard, Vancouver, ISO, and other styles

18

Bellamy, Stephen. "Resource partitioning between two sympatric Australian skinks, Egernia multiscutata and Egernia whitii." Connect to this title online, 2006. http://catalogue.flinders.edu.au/local/adt/public/adt-SFU20070124.145924/index.html.

Full text

APA, Harvard, Vancouver, ISO, and other styles

19

Ohlberger, Jan. "Eco-physiological and evolutionary divergence of a sympatric pair of coregonid fish." Doctoral thesis, Humboldt-Universität zu Berlin, Landwirtschaftlich-Gärtnerische Fakultät, 2009. http://dx.doi.org/10.18452/15865.

Full text

Abstract:

Die Bedeutung ökologischer Faktoren bei der Entstehung phänotypischer sowie genetischer Vielfalt durch natürliche Selektion, besonders bei sympatrischer Artbildung, ist derzeit ein Fokus der Evolutionsforschung. Gemeinsam vorkommende und nah verwandte Arten werden daher als Modellorganismen verwendet, um die Ursachen und Mechanismen ökologischer und evolutionärer Diversifizierung zu untersuchen. Ein sympatrisches Fisch-Artenpaar, für das eine sympatrische Artbildung auf Basis genetischer Analysen vermutet wird, existiert im norddeutschen Stechlinsee. Die zwei Maränenarten sind morphologisch kaum zu unterscheiden, zeigen eine ähnliche Nahrungszusammensetzung und kommen gemeinsam im Freiwasser, allerdings in leicht unterschiedlichen Wassertiefen, vor. Die Hypothese meiner Arbeit war, dass sich die Physiologie bzw. das Verhalten der Arten in Bezug auf die wichtigsten Umweltfaktoren ihres Lebensraumes, Futterdichte, Lichtintensität und Wassertemperatur unterscheiden. Daher haben wir Fraßeffizienz, Stoffwechselraten und Temperaturpräferenzen in Abhängigkeit dieser Faktoren bei beiden Arten untersucht, nachdem diese zuvor unter identischen Laborbedingungen herangezogen wurden. Wir fanden keinen Unterschied in der Fraßeffizienz, allerdings zeigten beide Arten je nach Temperatur unterschiedliche Stoffwechselraten sowie entsprechende Unterschiede in der Temperaturpräferenz. Die Ergebnisse legen nahe, dass temperaturbedingte physiologische Anpassungen sowie die Nutzung unterschiedlicher thermischer Mikrohabitate die zwischenartliche Konkurrenz verringern und eine gemeinsame Existenz ermöglichen. Um die mögliche Bedeutung einer solchen öko-physiologischen Spezialisierung für die Artbildung innerhalb des Sees einschätzen zu können, haben wir basierend auf den Freiland- und Labordaten ein mathematisches Evolutionsmodell entwickelt. Demnach ist ein Aufspalten einer Ausgangspopulation in zwei Populationen mit unterschiedlichen Temperaturoptima wahrscheinlich. Eine ökologische und evolutionäre Diversifizierung entlang des Temperaturgradienten ist somit ein empirisch und theoretisch plausibles Szenario für die sympatrische Artbildung der Stechlinsee-Maränen.
Abstract The role of ecological factors in generating phenotypic and genetic diversity through natural selection has received increasing attention in evolutionary biology during the last decade, especially with respect to diversification in sympatry. Sympatrically occurring and closely related species are used as model systems to study the causes and mechanisms of ecological and evolutionary diversification. A sympatric species pair of coregonid fish, for which a speciation in sympatry has been suggested based on genetic analyses, coexists in the German Lake Stechlin. The two species are morphologically similar planktivores with weak divergence in diet composition that co-occur within the pelagic area of the lake at slightly different water depths. Accordingly, it was hypothesized that the species would differ in physiology and behaviour with respect to the most important environmental factors of their natural habitat, food density, light intensity and water temperature. We studied the feeding efficiencies, metabolic rates, and temperature preferences of both species previously hatched and raised under identical laboratory conditions. We found no divergence in feeding efficiency, but significant differences in temperature-related metabolic costs as well as a corresponding difference in thermal preference. These results suggest that temperature-related physiological adaptations and the associated use of slightly different thermal microhabitats reduces exploitative competition between the species and facilitates their coexistence. To evaluate a potential role of this eco-physiological specialization for a speciation in sympatry, we developed a mathematical evolutionary model, based on our field observations and laboratory experiments. The model showed that an evolutionary splitting of an ancestral into two coexisting populations with different temperature optima is likely in this system. In conclusion, an eco-physiological and evolutionary diversification along the temperature-depth gradient of the lake is an empirically and theoretically plausible scenario for the sympatric speciation of the coregonids.

APA, Harvard, Vancouver, ISO, and other styles

20

Hippee, Alaine Constance. "Pre-mating reproductive isolation between three sympatric varieties of a specialist insect." Thesis, University of Iowa, 2016. https://ir.uiowa.edu/etd/3100.

Full text

Abstract:

Ecological interactions can play a major role in driving the process of speciation when they lead to a decrease in gene flow between diverging lineages. Various pre- and post-zygotic ecological barriers to gene flow are known to be important in speciation, but the specific barriers that cause the initiation of speciation are often unknown. Phytophagous (plant feeding) insects are powerful systems for evaluating ecologically based reproductive barriers because these organisms generally have a history of traits such as host shifting and host mediated sexual selection associated with speciation. Previous work on the sunflower maggot fly (Strauzia longipennis) indicates that three genetically distinct, diverging varieties co-occur on the host plant Helianthus tuberosus. In this work, I 1) confirm the existence of three diverging varieties by genotyping microsatellite loci, 2) evaluate the presence and strength of three pre-zygotic barriers to reproduction - habitat isolation, pre-mating sexual isolation, and allochronic isolation - between the varieties, and 3) measure the impacts of allochronic isolation on resource partitioning by evaluating host preference, oviposition location, and larval location between diverging Strauzia varieties sharing the same host plant species. I find evidence of pre-mating sexual isolation and allochronic isolation between the three varieties, indicating that these may be reproductive barriers that arise during early stages of divergence. These barriers may have occurred without (or before) the host-shift that is typical of many other diverging phytophagous insect systems. I also find evidence that allochronic isolation leads to resource partitioning of the single host plant resource, which may help the three varieties share the same host plant.

APA, Harvard, Vancouver, ISO, and other styles

21

Cobb, McCrea Andrew. "Home range characteristics of sympatric moose and white-tailed deer in Northern Minnesota." Thesis, Montana State University, 2004. http://etd.lib.montana.edu/etd/2004/cobb/CobbM04.pdf.

Full text

Abstract:

Moose (Alces alces) and white-tailed deer (Odocoileus virginianus) population numbers in northern Minnesota have fluctuated recently, possibly due to habitat changes, interspecific competition, and meningeal worm (Parelaphostrongylus tenuis). Little is known currently about the relative distribution and home range characteristics of sympatric moose and white-tailed deer in this area. Surveys were conducted during the winters of 1989 and 1991 to determine the relative distributions of moose and whitetailed deer pellet groups in Voyageurs National Park (VNP). Moose and white-tailed deer home ranges were determined using an adaptive kernel technique and applied to aerial radio telemetry relocations from 1989 to 1991. I examined the habitat selections of moose and white-tailed deer through compositional analysis at the home-range and corearea scales. Pellet transect data revealed a low abundance of moose and a high abundance of white-tailed deer and provided evidence of some spatial separation between moose and deer ranges in VNP. This evidence was supported by little interspecific home range overlap between radio collared moose and white-tailed deer. Moose home ranges in VNP were larger than any previously reported in the contiguous United States, and white-tailed deer home ranges were larger than any previously reported for the region. There was no apparent difference in home range sizes between the sexes for moose and white-tailed deer, although small sample sizes precluded precise statistical testing. Compositional analysis did not detect any habitat preference at the core-area scale for either moose or white-tailed deer. Both moose and white-tailed deer exhibited a significant preference for spruce/balsam fir habitats at the home-range scale. Canopy density and height preferences differed between moose and white-tailed deer at the homerange scale. Differential habitat preferences between moose and white-tailed deer in VNP might be related to the differences between these species' abilities to cope with northern mid-continent climates. The apparent spatial separation and different habitat preferences between moose and white-tailed deer might provide a refuge for moose from meningeal worm-infected white-tailed deer in VNP and could be a factor in the coexistence of the species.

APA, Harvard, Vancouver, ISO, and other styles

22

Nagel, Kathryn. "The effects of sympatric and allopatric hab species on calanoid copepod swimming behavior." Thesis, Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/50273.

Full text

Abstract:

Harmful algal blooms, commonly referred to as red tides, occur yearly with dramatic impacts on marine ecology, coastal economies, and human health. As a consequence, research into the zooplankton grazers that consume HABs is highly important. However, changes in ocean temperature may increase the range of many HABs, exposing historically naive copepods to new species and their associated chemicals. Little research into the impact of allopatric verses sympatric species, particularly on the immediate behavioral impact, has been performed, leaving the indirect fitness effects of HAB exposure and consumption relatively unknown. We measured alterations in the swimming behavior of the calanoid copepod Temora longicornis following exposure to sympatric Alexandrium fundyense and allopatric Karenia brevis treatments. After a 15-16 hours depuration period postA. fundyense exposure, T. longicornis exhibited increased average swimming speed and an elevated net to gross displacement ratio (NGDR). During exposure toK. brevis, copepods exhibited an immediate decrease in swimming speed and NGDR, as well as an increased frequency of jump behavior. However, these effects faded after an one-hour depuration period, and disappeared after a 15-16 hour depuration period. The alterations in swimming behavior demonstrated by the copepods treated A. fundyense may increase encounter rate with predators, while copepods treated with K. brevis remain in bloom conditions for longer periods of time, negatively affecting survivorship. Temora longicornis individuals also may be made more visible to predators due to the increase in jumps seen during treatment with K. brevis. These behavioral changes suggest how HABs escape from zooplankton grazer control by altering copepod swimming behavior, and the pattern of predator-prey evolution that occurs over time.

APA, Harvard, Vancouver, ISO, and other styles

23

Norris, Andrew J. "Sensory modalities, plasticity and prey choice in three sympatric species of whiting (Pisces:Sillaginidae) /." St. Lucia, Qld, 2004. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe17866.pdf.

Full text

APA, Harvard, Vancouver, ISO, and other styles

24

Wang, John Yu-Chao. "The classification of sympatric forms of bottlenose dolphins (genus Tursiops) in Chinese waters." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0020/NQ51021.pdf.

Full text

APA, Harvard, Vancouver, ISO, and other styles

25

Swan, Megan Cashman. "Soil Water Use and Root System Characteristics of C. maculosa and Sympatric Plants." Thesis, Montana State University, 2004. http://etd.lib.montana.edu/etd/2004/swan/SwanM0805.pdf.

Full text

Abstract:

Centaurea maculosa Lam. (spotted knapweed) is an introduced perennial forb that invades disturbed and undisturbed semiarid grasslands in the western United States. It forms dense monocultures and reduces native and desirable vegetation. We hypothesized that C. maculosa may succeed through a superior ability to access soil water. This study had two objectives, to compare soil water uptake patterns under C. maculosa, perennial grass, and R. hirta monocultures in the field on semiarid rangeland, and to compare root characteristics of C. maculosa and R. hirta plants grown under two soil water regimes in the greenhouse. For the first objective, we used two field sites in western Montana. We created four blocks of adjacent monoculture plots of three species (perennial grasses, C. maculosa and R. hirta) arranged in a randomized complete block design. Soil water dynamics were monitored throughout the growing season at six hour intervals in the upper 0.3 m of the soil profile using TDR, and weekly to biweekly at greater depths using a neutron moisture meter. Centaurea maculosa used more water than resident grasses when averaged over the soil profile and had greater water use than grass at greater depths later in the growing season. R. hirta displayed similar soil water uptake to C. maculosa in the second year of our study. There was no \"carry-over effect\" of low soil water contents at deep soil depths from the end of the first growing season to the beginning of the next. To address our second objective, we grew 10 individuals of C. maculosa and R. hirta under either \"dry\" or \"wet\" soil water conditions for 3 months in the greenhouse, then extracted, cleaned, stained and scanned their roots to quantify several root characteristics. Centaurea maculosa had lower root mass, root length, specific length, root length density and greater average root diameter than R. hirta under both soil water regimes. Centaurea maculosa had higher root mass ratios than R. hirta, but this may have been due to phenological differences at time of harvest or differences in nitrogen utilization. Our results suggest that C. maculosa may invade and persist in western rangelands due to its ability to take up soil water unavailable to native grasses which allows it to continue growth and photosynthesis late in the growing season. However, similar water uptake patterns and greater total root system size and efficiency of the non-invasive R. hirta indicate that C. maculosa does not have unique characteristics indicating superior belowground competitive ability, but may in fact share traits common to other late season tap-rooted forb species.

APA, Harvard, Vancouver, ISO, and other styles

26

Dijkstra, Peter Douwe. "Know thine enemy: intrasexual selection and sympatric speciation in Lake Victoria cichlid fish." [S.l. : [Groningen : s.n.] ; University Library Groningen] [Host], 2006. http://irs.ub.rug.nl/ppn/298119005.

Full text

APA, Harvard, Vancouver, ISO, and other styles

27

Robinson, James Alexander. "The comparative breeding ecology of sympatric common and Arctic terns in N.E. England." Thesis, Durham University, 1999. http://etheses.dur.ac.uk/4350/.

Full text

Abstract:

The life-history traits of two sympatric seabird species, the Common Sterna hirundo and Arctic Tern S. paradisaea, and the flexibility of these traits in relation to short and longer term changes in environmental conditions were measured at Coquet Island, N.E. England. The study focused primarily on inter and intraspecific differences in annual productivity and chick growth, adult time budgets and provisioning rates, and the relationships between these different aspects of reproductive performance. Of the two species, Common Terns delivered larger food items, delivered food at a higher rate to the nest and attended the nest more frequently, indicating that they made trips of shorter average duration. Daily metabolizable energy intake of chicks was about 30% higher in Common Terns than in Arctic Terns, yet the size-specific growth rates of the two species were almost identical, indicating a major difference between species in nestling energy budgets. Brooding appeared to play a less important role in the energy budgets of Common Terns, and the number of chicks that Arctic Terns could raise was probably limited not only by the rate at which parents could supply food to the nest but also by the requirements of chicks for brooding. Increased brood size, low annual food abundance and extreme weather conditions had a negative effect on chick mass development in both tern species. Flexibility of mass growth rates in Arctic and Common Terns may act as a fine-tuning mechanism to regulate provisioning in these species. By maintaining structural growth rates, final fledging mass and final fledging size of nestlings at the expense of retarded mass development rates, these species seem to be able to maximize annual reproductive output and possibly, for parents and nestlings, future survival. Predation of eggs and chicks was generally infrequent and affected mostly very young nestlings. However, Black-headed Gulls took many tern eggs in a year when inshore food supplies were particularly low.

APA, Harvard, Vancouver, ISO, and other styles

28

Noble, David Graham. "Coevolution and ecology of seven sympatric cuckoo species and their hosts in Namibia." Thesis, University of Cambridge, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.388489.

Full text

APA, Harvard, Vancouver, ISO, and other styles

29

Hrycyshyn, Gabrielle Elaine. "Survival probabilities and density of four sympatric species of freshwater turtles in Florida." [Gainesville, Fla.] : University of Florida, 2007. http://purl.fcla.edu/fcla/etd/UFE0021036.

Full text

APA, Harvard, Vancouver, ISO, and other styles

30

Kameyama, Saho. "Studies on the ecology of small cetaceans in the Istanbul Strait using acoustical information." 京都大学 (Kyoto University), 2016. http://hdl.handle.net/2433/215680.

Full text

APA, Harvard, Vancouver, ISO, and other styles

31

Miranda, Botello-Gut Beatrice Miranda Botello-Gut Beatrice Miranda Botello-Gut Beatrice. "Space use of sympatric woodpecker species: Implications for habitat use analysis and guild structure /." Zürich : ETH, 2006. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=16831.

Full text

APA, Harvard, Vancouver, ISO, and other styles

32

Blanchard, Mary Louise. "Locomotor behaviour and ecology of three sympatric lemur species in Mantadia National Park, Madagascar." Thesis, University of Liverpool, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.479032.

Full text

Abstract:

This study compares the locomotor behaviour of three sympatric species of folivorous (leaf-eating) lemur; Indri indri (indri), Propithecus diadema (diademed simpona) and HapaJemur griseus griseus (eastern lesser bamboo lemur). 1. indri and P. diadema are large bodied 'vertical clingers and leapers'. H. g. grise us is small bodied, combining 'vertical clinging and leaping' with quadrupedal walking. The three species were studied in Mantadia National Park, Madagascar. One social group each of 1. indri (n=4) and P. diadema (n=7) and two groups of H. g. griseus (n=6 and n=4) were followed during an eleven month period. Data was collected ad-hoc for locomotor mode and support use preferences, and by the method of 'focal animal sampling' for activity, diet, ranging and vertical spatial usage. In terms of activity, 1. indri and P. diadema were found to be diurnal, while H. g. griseus was crepuscular (activity at dawn and dusk). The active period for 1. indri and P. diadema mirrored sunrise and sunset, a pattern not observed in H. g. griseus. Length of feeding period did not seasonally alter in 1. indri, while rest and travel periods decreased in the austral (southern hemisphere) winter. Rest and travel periods of P. diadema decreased in winter while feeding time increased. Feeding time did not alter seasonally in H. g. griseus, while rest and travel increased slightly during the austral winter. There was considerable dietary overlap between 1. indri and P. diadema, up to 53%, but P. diadema maintained a more diverse diet. 1. indri had longer, but fewer, daily feeding bouts compared to P. diadema. All three study species displayed marked seasonality in diet. P. diadema had the largest home range (27ha), followed by 1. indri (13ha), while H. g .griseus had the smallest home ranges (3.5ha and 5.4ha). P. diadema had significantly longer daily path lengths (902m) compared to 1. indri (482m). The daily path length in 1. indri and P. diadema positively correlated with hours of daylight; decreasing daylight in the austral winter led to shorter path lengths. H. g. griseus were found at a mean height of 7.8m, lower than that of both 1. indri (12.6m) and P. diadema (lO.6m). The difference all three species is significant. 1. indri were observed to display a greater preference for non-vertical supports and P. diadema a greater preference for vertical supports. Contrary to expectation, although both species used supports with diameters sized 5.1 to IOcm most frequently, in comparison I. indri showed a preference for supports sized over 10.1cm and P. diadema for those smaller than IOcm. As expected, 1. indri and P. diadema utilised leaping more frequently during travel and all other modes less frequently, while during feeding leaping was used less frequently and all other modes more frequently. In summary a relationship was found to exist between support use, locomotion and stratum, and between stratum, dietary preference and predation risk for all three species. Contrary to prediction, seasonality was found to exert, at most, only a weak effect on the ecology of H. g. griseus. However, marked seasonality (yearly patterns of behaviour) was found in activity, diet and ranging for I. indri and P. diadema.

APA, Harvard, Vancouver, ISO, and other styles

33

Nicholls, Barry. "Habitat preferences and resource partitioning in sympatric pipistrelle bats Pipistrellus pipistrellus and Pipistrellus pygmaeus." Thesis, University of Aberdeen, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.424919.

Full text

APA, Harvard, Vancouver, ISO, and other styles

34

Montanari, Serena. "Microsatellite variation and reproductive interactions of common and Egyptian soles in Mediterranean sympatric demes." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2011. http://amslaurea.unibo.it/1802/.

Full text

APA, Harvard, Vancouver, ISO, and other styles

35

Harwood, Gyan. "Cooperation and colony size as drivers of differential resource use among sympatric social predators." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/45366.

Full text

Abstract:

Dietary differentiation is an integral component of species coexistence, and among solitary predators, body size differences allow each species to capture a different range of prey sizes. Social predators, however, are able to capture much larger prey than an individual, so prey size use is additionally influenced by group size and behavioural dynamics. To investigate this, we looked at cooperative hunting among three species of sympatric group-living spiders in Brazil that construct colonies of different sizes and are known to capture different sizes of prey. We performed feeding experiments to determine whether differential prey size use is produced by differences in group behaviour and group size. For each species we measured the level of cooperation and examined how colony size influenced group behaviour. We found that two of the species which live in equally large, multi-generational colonies displayed differences in their cooperation and prey size selectivity that are consistent with differences in prey size use previously observed: the species which captures larger prey in natural hunting scenarios showed higher levels of cooperation among hunters during the trials, and had more individuals participate when presented with large prey. The third species, which lives in smaller, temporary colonies, displayed the highest levels of cooperation and prey capture success, despite capturing the smallest prey on average in natural hunting scenarios. This disparity likely reflects the natural size distribution of colonies of this species, which is greatly dominated by solitary individuals that cannot capture the largest prey on their own. This study shows that behavioural differences among group-living predators, in addition to colony size differences, may be responsible for differential prey size use.

APA, Harvard, Vancouver, ISO, and other styles

36

Kabir, Md Mofizul. "Behavioural ecology of two sympatric langur species in the semi-evergreen forest of Bangladesh." Thesis, University of Cambridge, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.620521.

Full text

APA, Harvard, Vancouver, ISO, and other styles

37

Townsend, lan R. "The population biology of two sympatric alien gallwasps and their recruitment of natural enemies." Thesis, University of Reading, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.658877.

Full text

Abstract:

There remain a number of research gaps in the fields of Population and Community Ecology. These include gaps in our understanding of the population biology of species which exhibit complex life-cycles and life history strategies that might mitigate against environmental variability. There are also gaps in our knowledge of the interactions between newly resident species (e.g. alien species etc.) and communities in their new ranges. The establishment in Britain of two closely related and niche sharing species of alien phytophagous cynipid wasps, Andricus quercuscalicis (Burgsdorf, 1783) (Hymenoptera: Cynipidae) andA. grossulariae (Giraud, 1859) (Hymenoptera: Cynipidae) - both of which have complex life-cycles with nonoverlapping sexual and asexual generations - provide a rare opportunity to address such research gaps. While A. quercuscalicis was first recorded in the British Isles in the 1950s and has been studied extensively since, A. grossulariae established only over the last decade. In Chapter 2, The population biology of two niche sharing alien · I gal/wasps, I ask whether the arrival of A. grossulariae has caused changes in the temporal patterns of galling rates, patterns of diapause, and overwintering mortality to previous observations and fmd that there is some fluctuation in most cases. I also ask if there is now evidence of a competition effect between A. quercuscalicis and A. grossulariae in any stage of their life-cycle and find that there is suggestion of a small competition effect occurring in the sexual generation.

APA, Harvard, Vancouver, ISO, and other styles

38

Rova, Emma. "The role of Assortative Mating in the Initial Stages of Sympatric and Parapatric Speciation." Doctoral thesis, Uppsala universitet, Zooekologi, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-130764.

Full text

Abstract:

Divergence in the face of gene flow is perhaps the most wildly disputed subject among researchers through time. The debate is an old one and we find its origin as far back as the era of Darwin. The theories dealing with sympatric and parapatric speciation, its processes and ecological conditions, are numerous and the empirical data supporting the ideas is constantly growing. However, the reach of a consensus almost seem as distant as ever. Two fundamental prerequisites can be identified for the evolution of divergence with gene flow, the act of disruptive selection, and the development of assortative mating. A set of models in which speciation with gene flow seem particularly likely is when a shift occurs in host preference in phytophagous insects and mating takes place on the host. In the work behind this thesis, the role of assortative mating in the initial stages of sympatric and parapatric speciation has been studied, as has the interaction between assortative mating and inbreeding and how it effects speciation in small sympatric populations, an aspect not much attended to earlier in the literature. My results show that assortative mating based on resource preference, can evolve rapidly upon secondary contact, and even in parapatric populations with a migration rate of 8% (13-15 individuals) per generation. However for assortative mating to be maintained selection against hybrids is needed. My results also suggests that small inbred populations have a hard time coping with strong assortative mating an as a consequence tend to relax their mating preferences to avoid inbreeding depression. Based on these results, I advocate for the importance of considering not only assortative mating in itself, but also the joint effects of assortative mating and inbreeding when dealing with theories of speciation with gene flow.

APA, Harvard, Vancouver, ISO, and other styles

39

Eriksson, Olivia. "Sympatric Divergence in Whitefish Dwarfs : An investigation of phenotype-environment correlations in whitefish dwarfs." Thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-187175.

Full text

Abstract:

Recent studies have found populations of European Whitefish (Coregonus lavaretus) to be under the process of divergence induced by a predator (pike, Esox lucius). This has caused whitefish to diverge into similar ecotypes but in separate lakes. Even though there are established ecotypes, these do display a high degree of variation, especially among whitefish dwarfs. The underlying mechanisms has not been fully understood and other determining ecological factors than predation are yet to be explored. In this study, I examine whether there are phenotype-environment correlation between whitefish dwarfs that could help identifying the selection pressures shaping this variation between whitefish dwarfs in different lakes. The morphological features of interest were body size and number of gill rakers since these are determining features of divergence. The environmental variables of interest were features of the lake in questions and its surrounding area. No significant correlations were found between the environmental variables and the body size of whitefish dwarfs. I was however through this study able to conclude significant results regarding phenotype-environment correlations between the number of gill rakers in whitefish dwarfs and the combined effects of lake percentage, lake area, temperature and number of (other fish) species in the lake from which they were sampled. It is probable that this is due to these variables affecting the niche space in which the whitefish dwarfs can diverge. Lakes with more potential refuges from pike will result in more divergence in whitefish dwarfs and vice versa. I can hereby propose a model containing these four environmental variables for how they affect the number of gill rakers in whitefish dwarfs.

APA, Harvard, Vancouver, ISO, and other styles

40

Thorén, Sandra Ingrid Kristina [Verfasser]. "Comparative feeding ecology of two sympatric mouse lemurs (Microcebus spp.) in northwestern Madagascar / Sandra Thorén." Hannover : Bibliothek der Tierärztlichen Hochschule Hannover, 2011. http://d-nb.info/1013480368/34.

Full text

APA, Harvard, Vancouver, ISO, and other styles

41

Schmieder, Daniela Anna [Verfasser]. "Niche partitioning in similar, closely related sympatric bat species? : A mechanical approach. / Daniela Anna Schmieder." Konstanz : Bibliothek der Universität Konstanz, 2017. http://d-nb.info/1137161507/34.

Full text

APA, Harvard, Vancouver, ISO, and other styles

42

Medina, Raul Francisco. "The role of host-plant species in the differentiation of sympatric populations of hymenopteran parasitoids." College Park, Md. : University of Maryland, 2005. http://hdl.handle.net/1903/3084.

Full text

Abstract:

Thesis (Ph. D.) -- University of Maryland, College Park, 2005.
Thesis research directed by: Entomology. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.

APA, Harvard, Vancouver, ISO, and other styles

43

Bryce, Jennifer M. "Habitat use by sympatric populations of red and grey squirrels : the implications for conservation management." Thesis, University of Oxford, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.365722.

Full text

APA, Harvard, Vancouver, ISO, and other styles

44

Keen, Eric Michael. "Whales of the rainforest| Habitat use strategies of sympatric rorqual whales within a fjord system." Thesis, University of California, San Diego, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10256131.

Full text

Abstract:

The energy needs of rorqual whales (f. Balaenopteridae) govern their relationship to marine habitats during the foraging season. However, their cryptic foraging strategies and extreme feeding behaviors complicate our effort to identify and protect habitats “critical” for rorquals. What is the relationship between rorquals and their habitat, and how must that shape conservation strategies? I addressed this question in the case of sympatric humpback (Megaptera novaeangliae) and fin whales ( Balaenoptera physalus) in the marine territory of the Gitga’at First Nation in the Kitimat Fjord System of British Columbia. For three summers (2013-2015) I studied whales, their prey, and their environment aboard the RV Bangarang using oceanographic station sampling, systematic transect surveys, and opportunistic focal follows of whales (Chapter 1). Ocean sampling demonstrated the strong coupling of water features with offshore patterns in storm forcing and regional meteorology (Chapter 2). By combining these surveys with a long-term Gitga’at dataset, area humpback whales were found to practice a structured and persistent pattern in seasonal habitat use, which demonstrates how complex and habitat-specific a rorqual’s habitat use can be (Chapter 3). Both humpback and fin whales were found to respond to changes in krill supply in aggregative and behavioral thresholds that are set by a combination of intrinsic energetic needs and the context of local prey supply (Chapter 4). Associations with non-prey habitat features were markedly different in the two species (Chapter 5). Humpback distribution was more closely coupled to that of their prey and other habitat features, while fin whale distribution was driven broadly by site fidelity. Novel spatial analytics were used to identify the most probable environmental cues used by foraging whales (Chapter 6). Both species were found to be particularly sensitive to the depth of prey layers, which is governed largely by oceanographic features (Chapter 7). This coupling of habitat features and feeding performance influences the competitive dynamics of rorqual whales. The findings in this case study advance general theories on marine predator ecology and conservation, and have direct implications for the management of Gitga’at territory and the identification of fin whale critical habitat in Pacific Canada.

APA, Harvard, Vancouver, ISO, and other styles

45

Lin, Wuying. "Comparative Reproductive Biology of a Rare Endemic Orchid and its Sympatric Congeners in Southwestern China." FIU Digital Commons, 2012. http://digitalcommons.fiu.edu/etd/570.

Full text

Abstract:

Comparative studies on endangered species and their more common congeners can shed light on the mechanism of species rarity, and enable conservationists to formulate effective management strategies. I compared the breeding and pollination systems of the endangered Geodorum eulophioides and its two more common sympatric congeners in subtropical China. Geodorum eulophioides and G. recurvum were self-compatible, both depending on Ceratina cognata for fruit production, while G. densiflorum can autonomously self. Although the floral visitation frequency of G. eulophioides was the highest among the three, its natural fruit set was similar to that of G. recurvum, but both lower than that of G. densiflorum. These results partially explain the difference in species abundance. Coupled with severe habitat loss and degradation, the extremely low pollinator visitation and natural fruit set of G. eulophioides calls for rapid establishment of ex-situ collection, in conjunction with improving in-situ habitat. Natural hybridization tendencies were also studied among species.

APA, Harvard, Vancouver, ISO, and other styles

46

Bujila, Ioana. "Plasmodium falciparum-mediated modulation of innate immune cells: responses and regulation." Doctoral thesis, Stockholms universitet, Institutionen för molekylär biovetenskap, Wenner-Grens institut, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-126138.

Full text

Abstract:

Plasmodium falciparum (P. falciparum) infection modulates the response of innate immune cells. The aim of this work was to study the impact of P. falciparum infection and P. falciparum-derived molecules on the response of dendritic cells (DC) and monocytes. In paper I we investigated the effects of natural hemozoin (nHZ), a P. falciparum-derived molecule, on the phenotype and functionality of DC. We found that exposure to nHZ impaired the capacity of DC to mature. Paper II is a follow-up on paper I, where the underlying transcriptional events preceding the nHZ-induced impairment of DC maturation were investigated. More specifically, we examined the involvement of certain transcription factors, subunits of chromatin remodeling complexes and histone modifications in the regulation of DC maturation. Our findings suggest that nHZ-exposure of DC does not lead to recruitment or enrichment of molecules needed for transcriptional activation. In paper III we investigated P. falciparum effects in vivo in sympatric ethnic groups with differential susceptibility towards P. falciparum infection living in Burkina Faso. The aim of this study was to establish the transcriptional networks underlying the relatively better protection against P. falciparum infection observed in the Fulani ethnic group compared to other sympatric ethnic groups. Our findings reveal differential gene expression in monocytes of infected Fulani compared to uninfected Fulani and the difference concerned multiple classes of genes including signal transduction, immunological responses and chromatin remodelers. The results provide new aspects on molecules and regulatory mechanisms that are involved in the relatively more protective response against P. falciparum infection. Taken together, the work presented in this thesis leads to a deeper understanding of the P. falciparum-induced modulation of responses of innate immune cells and the underlying mechanisms possibly regulating those responses.

At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Manuscript. Paper 3: Manuscript.

APA, Harvard, Vancouver, ISO, and other styles

47

Conners, Melinda G. "Comparative behavior, diet, and post-breeding strategies of two sympatric North Pacific albatross species (Phoebastria sp.)." Thesis, University of California, Santa Cruz, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=3746719.

Full text

Abstract:

A fundamental condition of the struggle for existence is resource limitation. Optimal foraging theory describes how individuals refine behavior to most efficiently exploit available resources. For colonial breeding animals, such as seabirds, competition for limited resources is amplified by a high density of competitors at feeding grounds near the colony, which can lead to a diversification of foraging strategies that best exploit available resources. Laysan and black-footed albatrosses (Phoebatria immutabilis and P. nigripes, respectively) breed sympatrically and synchronously in dense colonies on small atolls throughout the northwestern Hawaiian Islands. While the distributions and habitat preferences of these congeners are well described, the variability in foraging strategies driven by niche partitioning is not. In chapter 1, I used fine-scale behavioral data from GPS data-loggers to tease apart subtle behavioral nice partitioning between and within Laysan and black-footed albatrosses constrained to poor-nutrient tropical waters during the most energetically-demanding reproductive stage in birds: the brood-guard. Albatrosses showed discrete behavioral partitioning both between and within species, which was driven by differences in nocturnal and diurnal foraging and by sex-specific strategies. Black-footed albatrosses exhibited greater variability in foraging patterns suggesting they may experience strong intraspecific competition at Tern Island. In chapter 2, I employed a novel adaptation of a biochemical diet analysis, quantitative fatty acid analyses, to investigate dietary niche partitioning across the breeding season. This analysis characterized diet of individual adult albatrosses across the breeding season, from incubation to the chick-brood, for the first time in these species. Additionally, this research extended beyond diet characterization to quantify dietary dependence on fisheries-associated resources for these two species. One of the primary threats to albatross is the incidental mortality of birds from fisheries bycatch, therefore, understanding the incidence of fisheries-associated food in the diet of a breeding colony of albatrosses could have important conservation implications. While older birds tended to consume more squid than younger birds, we did not identify an age bias in birds that exploited fisheries resources. Parallel with results from the behavioral analysis in chapter 1, I found that black-footed albatrosses had greater dietary flexibility than Laysan albatrosses at a population level, and a greater degree of dietary specialization at the individual level. In the final chapter, I looked at how the obligatory act of flight feather molt impacted activity levels and space use across the post-breed migrations, when albatrosses are freed from central place foraging constraints, but limited by demands of self-maintenance. I found that activity levels, but not habitat use, were impacted by molt extent. Habitat use appeared to be primarily driven by consistent individual preferences, with birds showing a high degree of site fidelity to their post-breeding molting grounds. A clear decrease in home range size with age indicated that birds spend less time searching for profitable feeding grounds when they are older, likely a product of accumulated memory and experience in these long-lived species.

APA, Harvard, Vancouver, ISO, and other styles

48

Weber, Manuel. "Ecology and conservation of sympatric tropical deer populations in the Greater Calakmul Region, south-eastern Mexico." Thesis, Durham University, 2005. http://etheses.dur.ac.uk/2777/.

Full text

Abstract:

The conservation and management of tropical deer populations need both knowledge of the ecology and natural history of deer and an understanding of the utilization of deer populations by humans. The south-eastern portion of the Yucatan Peninsula in Mexico is the region with the largest ungulate diversity in Mesoamerica, including three of the five species of deer found in Mexico. For centuries, human populations have been harvesting deer for subsistence in this region. Little is know on the ecology and conservation of ungulate populations undergoing subsistence harvesting in Mesamerica. This thesis is the result of a long-term study (1996-2001) on the population, community ecology and sustainable management of the Yucatan Peninsula brown brocket deer (Mazama pandora), red brocket deer (Mazama americana) and white-tailed deer (Odocoileus virginianus) in the Greater Calakmul Region՝ (GCR), south eastern Mexico. Chapter two addresses the estimation of deer abundance, densities, population structure and habitat use of sympatric populations of these three species of deer. Chapter three outlines the relationships of the deer diet with aspects of habitat ecology such as fruit phenology, availability and seasonality. Chapter four describes the spatial and temporal patterns of subsistence hunting of tropical deer populations with the use of a novel technique incorporating both GIS/GPS technologies and participatory research. The abundance of deer in the GCR remained stable during a continuous monitoring period of five years and no effects of hunting were detected in the populations of the two Mazama species. A steady decline was detected in the populations of white-tailed deer that might be attributed to over-harvesting by subsistence hunters. Densities of the three species of deer are similar or higher that those reported elsewhere in the Neotropics. Mazama americana presented strong preferences in habitat use for the Tall Perennial Forest, while M pandora and o. virginianus used habitats in relation with availability. The population structure of the three species of deer resembles a stable population with the majority of individuals found in younger age classes but older individuals still found in ages above 12 years old (the cementum annuli technique for age determination was used for the first time in a tropical deer population). Mazama americana is a frugivore deer with its diet composed of up to 80% fruits year-round, while M. pandora and o.virginianus are both frugivores and browsers. Fruit availability for deer was strongly linked with fruit phonological patterns of the major planit species composing the deer diet year-round. A critical period with low fruit availability and potential dietary stress for deer was found during the dry season (April-May). The Zapote tree {Manilkara zapota) might be a keystone plant resource in the region. Subsistence hunting of deer is widespread in the GCR region, but deer hunting seems to be sustainable in part due to the dynamic patterns in spatial and temporal location of hunters in the landscape. The spatial and temporal patterns of deer hunting might be responsible for the creation of natural refuges and source/sink areas for deer populations. The conservation and management of tropical deer populations in the GCR and Meso-America are discussed in the light of these findings.

APA, Harvard, Vancouver, ISO, and other styles

49

Neal, Orin J. "Responses to the audio broadcasts of predator vocalizations by eight sympatric primates in Suriname, South America." [Kent, Ohio] : Kent State University, 2009. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=kent1245291915.

Full text

Abstract:

Thesis (M.A.)--Kent State University, 2009.
Title from PDF t.p. (viewed Jan. 26, 2010). Advisor: Marilyn Norconk. Keywords: predation; anti-predator strategies; alarm calls. Includes bibliographical references (p. 111-120).

APA, Harvard, Vancouver, ISO, and other styles

50

Vitale, Jessica. "The olfactory behaviour of spotted hyaenas (Crocuta crocuta) and sympatric mammals in the Okavango Delta, Botswana." Thesis, University of Nottingham, 2018. http://eprints.nottingham.ac.uk/48855/.

Full text

Abstract:

Understanding the natural behaviour and coexistence of species is important for the conservation of intact ecosystems, and behavioural studies can enhance our knowledge of processes such as communication and competition. I investigated the social dynamics and scent-marking behaviour of spotted hyaenas (Crocuta crocuta), and the occurrence of interspecific olfactory eavesdropping among African mammals, within the Okavango Delta ecosystem of Botswana. First, social network analysis found that the hyaena population was comprised of five main clans that maintained territories but whose home ranges overlapped considerably. Scavenging at large carcasses involved associations between individuals from different clans and resulted in relative tolerance toward territorial intruders. Second, observations of communal latrine use found that latrines are likely involved in territorial advertisement by hyaena clans, and cyclical patterns of latrine growth and decline were linked to annual rainfall. Third, a translocation experiment showed that hyaena scats appear to be less important for hyaena communication than other cues associated with latrines, especially as hyaenas did not differ in their behaviour towards scat originating from latrines located in resident versus non-resident clan home ranges. Heterospecific mammals investigated, scent-marked, and were vigilant at hyaena latrines, suggesting a potential function for hyaena latrines in interspecific eavesdropping and/or communication. Fourth, a urine presentation experiment found that the investigation of sympatric predator urine by African mammals stimulated vigilance behaviour, suggesting that olfactory signals provide information about predation risk. Hyaenas exhibited context-specific differences in behaviour towards predator urine: they were more likely to investigate urine samples alongside indicators of predator activity (i.e. carrion odour, carcasses) and were most likely to exhibit vigilance at carcasses when exposed to urine from lions and wild dogs. This study greatly enhanced our understanding of spotted hyaena behaviour within the Okavango Delta, an important ecosystem for the conservation of African large predators. Furthermore, this study provided the first experimental evidence of the role of hyaena scats in intraspecific communication and interspecific olfactory eavesdropping at latrines. My research findings regarding the population’s clan structure and home ranges will form the foundation for subsequent investigation into human-wildlife conflict in the study area. Furthermore, the results from two scent experiments shed light on the potential importance of olfactory signals for mediating interspecific interactions among African mammals, particularly among large predators.

APA, Harvard, Vancouver, ISO, and other styles

Dissertations / Theses on the topic 'Sympatric'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles