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1

Tokushima, Hideyuki, e Peter J. Jarman. "Ecology of the rare but irruptive Pilliga mouse, Pseudomys pilligaensis. IV. Habitat ecology". Australian Journal of Zoology 63, n. 1 (2015): 28. http://dx.doi.org/10.1071/zo14057.

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Abstract (sommario):
We determined preferences of the Pilliga mouse, Pseudomys pilligaensis, for habitat attributes (ground and vegetation cover) through phases of a population irruption, and characterised refuge sites used when environmental conditions were unfavourable. In general, P. pilligaensis preferred areas with substrate dominated by sand and shrubs rather than rock or litter. However, its habitat selection changed with phases of the irruption. In the Increase phase, it showed no strong habitat preferences, perhaps because the abundance of food (seeds) overrode preferences for more stable habitat values. Its sensitivity to habitat variables increased in the Peak phase. In the Low phase, mice preferred ground cover with higher proportions of sand and shrubs, and lower proportions of rock and litter. Regression analyses suggested that sandy substrate is the most important factor for the refuge habitat of P. pilligaensis, perhaps because a sandy surface can support more understorey shrubs which provide seeds and protection from predators, and provides sites for burrows. Judging from areas where P. pilligaensis was caught during the Low phase, water run-on areas could also characterise refuge habitats. However, further studies are needed to define the species’ refuge habitats fully.
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2

Crain, Benjamin J., Ana María Sánchez-Cuervo, Jeffrey W. White e Steven J. Steinberg. "Conservation ecology of rare plants within complex local habitat networks". Oryx 49, n. 4 (24 febbraio 2014): 696–703. http://dx.doi.org/10.1017/s0030605313001245.

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AbstractEffective conservation of rare plant species requires a detailed understanding of their unique distributions and habitat requirements to identify conservation targets. Research suggests that local conservation efforts may be one of the best means for accomplishing this task. We conducted a geographical analysis of the local distributions of rare plants in Napa County, California, to identify spatial relationships with individual habitat types. We measured the potential contribution of individual habitats to rare plant conservation by integrating analyses on overall diversity, species per area, specificity-weighted richness, presence of hotspots, and the composition of the rare plant community in each habitat type. This combination of analyses allowed us to determine which habitats are most significant for rare plant conservation at a local scale. Our analyses indicated that several habitat types were consistently associated with rare plant species. In broad terms, grasslands, oak forests, coniferous forests, wetlands, serpentines, chaparral, and rock outcrops were most consistently highlighted. No single habitat stood out in every analysis however, and therefore we conclude that careful selection of an assemblage of habitats that best represents diverse, restricted and unique rare plant communities will be the most efficient approach to protecting rare plant habitat at local scales. Accordingly we present a means of identifying conservation targets and protecting global biodiversity through local efforts.
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3

Meynecke, J. O. "Coastal habitat connectivity ? implications for declared fish habitat networks in Queensland, Australia". Pacific Conservation Biology 15, n. 2 (2009): 96. http://dx.doi.org/10.1071/pc090096.

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Estuaries are widely recognized as key habitats supporting nearshore secondary production and catch of commercial fisheries. In Queensland, some of these coastal marine habitats are protected by the declared fish habitat programme run by the Department of Primary Industries and Fisheries. Expected environmental changes for Australian estuarine systems include reduced freshwater flow, increased sedimentation and with them, a loss of connectivity. At present, the relationship between the protected declared fish habitat and habitat connectivity remains unknown. By comparing long term coastal fish catch data with geomorphic characteristics of coastal habitats structural connectivity was previously identified as a potential driver of commercial fish catch in Queensland. An ecology landscape approach was used for this study to identify potential fish habitat hotspots along the coastline of Queensland thus allowing better defined networks of declared fish habitats. A comparison between this approach and the current declared fish habitats demonstrated potential deficits and provided important insights for fisheries management. Declared fish habitats should be placed in coastal habitats with high structural connectivity to ensure sustainability of fisheries in light of environmental changes.
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4

Kocik, John F., e C. Paola Ferreri. "Juvenile production variation in salmonids: population dynamics, habitat, and the role of spatial relationships". Canadian Journal of Fisheries and Aquatic Sciences 55, S1 (1 gennaio 1998): 191–200. http://dx.doi.org/10.1139/d98-015.

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Anadromous Atlantic salmon (Salmo salar) exhibit a complex life history that requires the use of habitats that span several different temporal and spatial scales. While fisheries scientists have investigated the various elements of habitat and how they affect Atlantic salmon growth and survival, these studies typically focus on requisite requirements for a single life history stage. Current advances in our understanding of salmonid populations in lotic systems indicates that ignoring the spatial positioning of different habitats and dispersal capabilities of fish between them may affect estimates of habitat quality and production of juvenile Atlantic salmon. Using the concepts of juxtaposition and interspersion, we hypothesize that discrete functional habitat units (FHU) occur within river systems and that the spatial structure of FHU affects fish production. We present a method to delineate FHU using habitat maps, fish ecology, and spatial habitat characteristics. Utilizing a simulation model, we illustrate how modeling FHU structure of spawning and rearing habitat in a river system can improve our understanding of juvenile Atlantic salmon production dynamics. The FHU concept allows a flexible approach to more comprehensive analyses of the impacts of habitat alterations, seasonal habitat shifts, and spatial ecology of salmonids at various scales.
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5

Grzędzicka, Emilia. "Assessment of Habitat Selection by Invasive Plants and Conditions with the Best Performance of Invasiveness Traits". Diversity 15, n. 3 (25 febbraio 2023): 333. http://dx.doi.org/10.3390/d15030333.

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Abstract (sommario):
Habitat selection is one of the fundamental concepts in ecology and means that each organism should choose the habitat that will maximize its success. Invaders may be an underestimated object in research on habitat selection. Invasive plants experience enormous propagule pressure and bear the costs of spreading in disturbed anthropogenic habitats. It means that they do not necessarily achieve maximum invasiveness traits in such habitats, which they selected to colonize. This study aimed to assess habitats where invaders are likely to occur from the set of all available ones in the landscape and the habitats with the best performed traits of invaders. The research was conducted on 52 and 112 plots in 2019 and 2021, respectively, in South-Eastern Poland, and the invasive plants were Caucasian hogweeds Heracleum sp. In the first year, the circle plots had a 50 m radius and were to measure habitat areas and traits of hogweeds (height, number of individuals in the plot, cover, and number of flowering specimens). Detrimental correspondence analysis and linear mixed model investigated that hogweeds achieved the best performance reflected by traits in continuous habitats—meadows and forests. In the second year, the plots to measure habitats had a 100 m radius. The reference plots were far from the invasion exposure, and the paired control vs. Heracleum ones had the same habitats with the potential to be invaded. The generalized linear mixed model showed that the probability of the hogweeds occurrence was higher when the habitat was overgrowing with a simultaneous decrease in open areas and in the increasing ruderal area with a decrease in bushes. The impact of the invader’s habitat on the invasion performance depended on the purpose of habitat selection. When invaders spread and increased invasive extent or appeared in habitat edges, they did not reach the highest traits, the best performing in continuous habitats. The specificity of habitat selection of invaders is another aspect that distinguishes invasion science from classic ecology.
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6

Moore, Kelly M. S., e Stanley V. Gregory. "Summer Habitat Utilization and Ecology of Cutthroat Trout Fry (Salmo clarki) in Cascade Mountain Streams". Canadian Journal of Fisheries and Aquatic Sciences 45, n. 11 (1 novembre 1988): 1921–30. http://dx.doi.org/10.1139/f88-224.

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Abstract (sommario):
Emergent cutthroat trout fry (Salmo clarki) were observed in the margins, backwaters, and side channels, collectively called "lateral habitats," of three study streams with different riparian vegetation. Most fry remained in these lateral habitats until the end of their first summer. The abundance of cutthroat fry was proportional to the area of lateral habitat in each of the study streams. Average size and growth rate of fry were related to the effect of site elevation on stream temperature and the influence of riparian vegetation on the availability of invertebrate food. Lateral habitats are characterized by slow, shallow-water, abundant detritus and benthic invertebrate assemblages of high density. Stream margins and backwaters provide gradients of depth and velocity, cover, and access to food that are appropriate to the habitat requirements of fry. Because fry populations are closely related to the abundance and quality of lateral habitats in small streams, these habitats should be included in the assessment of habitat requirements of cutthroat trout.
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7

Knierim, Tyler. "Spatial ecology study reveals nest attendance and habitat preference of banded kraits (Bungarus fasciatus)". Herpetological Bulletin, n. 150, Winter 2019 (31 dicembre 2019): 6–13. http://dx.doi.org/10.33256/hb150.613.

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An understanding of the spatial ecology of species living in and around human-dominated habitats is needed to develop conflict mitigation strategies and predict how organisms cope with ongoing anthropogenic habitat alteration. Here we present the results of a six-month telemetry study in Thailand of the banded krait (Bungarus fasciatus), a venomous elapid snake. We quantified home range size and habitat use of three adult kraits (1 male, 2 females) in an agricultural habitat. The kraits travelled an average of 47.20 m ± 23.54 m between shelter sites and occupied home ranges of on average 21.45 ha ± 19.56 ha (95 % dynamic Brownian Bridge Movement Models). They preferred to seek day time refuge amongst less disturbed habitat features, including waterways and rice paddy dykes, while avoiding routinely disturbed monoculture fields. The two female kraits also exhibited reduced movement while simultaneously attending their nests in a shared burrow complex. Fifteen neonates were observed emerging from the nest site. We recommend further investigation of banded krait reproductive ecology and ability to persist in heavily disturbed habitats.
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8

Martín, José, Jesús Ortega, Roberto García-Roa, Gonzalo Rodríguez-Ruiz, Ana Pérez-Cembranos e Valentín Pérez-Mellado. "Effects of Anthropogenic Disturbance of Natural Habitats on the Feeding Ecology of Moorish Geckos". Animals 13, n. 8 (20 aprile 2023): 1413. http://dx.doi.org/10.3390/ani13081413.

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Abstract (sommario):
Urbanization and anthropic influences can drastically modify a natural habitat and transform it into an easily recognizable “urban habitat”. Human activities can also induce less severe modifications of what apparently might still look like natural habitats. Therefore, these subtle alterations may be hidden but can still cause important negative effects on plant and animals. In contrast, some species seem able to take advantage of these anthropic alterations. Here, we examined the possible effects of the anthropogenic disturbance of an apparent natural habitat on the feeding ecology and body condition of Moorish geckos, Tarentola mauritanica. For this, we compared microhabitat structure, invertebrate availability, the diet composition (estimated from fecal contents), diet selection patterns and body condition of the two populations of geckos inhabiting two contiguous small islands. These islands have similar environmental characteristics, but highly contrasting differences in urbanization and anthropogenic influence. We found that, although the abundance of potential invertebrate prey was similar on both habitats, the diversity of invertebrate prey was lower in the altered habitat. As a consequence, although composition of the diet of geckos was similar on both islands, the diversity of prey and food niche breadth were lower in the altered habitat, and patterns of diet selection changed. However, these inter-habitat differences did not seem to affect the body size and body condition of geckos. We discuss how flexibility in feeding ecology may allow some species to cope with small anthropic disturbances of the habitat.
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9

Gaillard, Jean-Michel, Mark Hebblewhite, Anne Loison, Mark Fuller, Roger Powell, Mathieu Basille e Bram Van Moorter. "Habitat–performance relationships: finding the right metric at a given spatial scale". Philosophical Transactions of the Royal Society B: Biological Sciences 365, n. 1550 (27 luglio 2010): 2255–65. http://dx.doi.org/10.1098/rstb.2010.0085.

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Abstract (sommario):
The field of habitat ecology has been muddled by imprecise terminology regarding what constitutes habitat, and how importance is measured through use, selection, avoidance and other bio-statistical terminology. Added to the confusion is the idea that habitat is scale-specific. Despite these conceptual difficulties, ecologists have made advances in understanding ‘how habitats are important to animals’, and data from animal-borne global positioning system (GPS) units have the potential to help this clarification. Here, we propose a new conceptual framework to connect habitats with measures of animal performance itself—towards assessing habitat–performance relationship (HPR). Long-term studies will be needed to estimate consequences of habitat selection for animal performance. GPS data from wildlife can provide new approaches for studying useful correlates of performance that we review. Recent examples include merging traditional resource selection studies with information about resources used at different critical life-history events (e.g. nesting, calving, migration), uncovering habitats that facilitate movement or foraging and, ultimately, comparing resources used through different life-history strategies with those resulting in death. By integrating data from GPS receivers with other animal-borne technologies and combining those data with additional life-history information, we believe understanding the drivers of HPRs will inform animal ecology and improve conservation.
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10

Mumford, Eric P. "Habitat: ecology thinking in architecture". Journal of Architecture 26, n. 7 (3 ottobre 2021): 1112–15. http://dx.doi.org/10.1080/13602365.2021.1984025.

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11

Memmott, Jane. "Food webs: a ladder for picking strawberries or a practical tool for practical problems?" Philosophical Transactions of the Royal Society B: Biological Sciences 364, n. 1524 (27 giugno 2009): 1693–99. http://dx.doi.org/10.1098/rstb.2008.0255.

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While food webs have provided a rich vein of research material over the last 50 years, they have largely been the subject matter of the pure ecologist working in natural habitats. While there are some notable exceptions to this trend, there are, as I explain in this paper, many applied questions that could be answered using a food web approach. The paper is divided into two halves. The first half provides a brief review of six areas where food webs have begun to be used as an applied tool: restoration ecology, alien species, biological control, conservation ecology, habitat management and global warming. The second half outlines five areas in which a food web approach could prove very rewarding: urban ecology, agroecology, habitat fragmentation, cross-habitat food webs and ecosystem services.
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12

Lélias, Marie-Loup, Alban Lemasson e Thierry Lodé. "Social organization of otters in relation to their ecology". Biological Journal of the Linnean Society 133, n. 1 (24 marzo 2021): 1–27. http://dx.doi.org/10.1093/biolinnean/blab016.

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Abstract Otter species are known to fluctuate intraspecifically from a solitary lifestyle to group-living arrangements. By examining what is known about habitat use and foraging style in otters of 13 different species, based on 93 studied sites, we assessed (1) the relationship between social habits and preferred habitats, (2) the relationship between species and prey preferences, and (3) the effect of predator avoidance on their social organization in order to assess the socio-ecological factors influencing otters. Females remain the core of their social stability. We show the major influence of habitats and feeding strategies (i.e. socio-ecology) of otters. The different species of solitary otters most often inhabit linear environments, such as freshwater ecosystems or wave-exposed marine coasts, and their habitat is often subject to disturbances that fragment their functional continuity. Social otters are more often found in extensive habitats with high plant cover, regular food resources and in areas with large predators compared to solitary species. The maintenance of regular resources and the fact that the main trophic resources are replenished rapidly might be determining factors driving sociality. Group-living and bachelor congregations among otters can also respond to pressure from large predators. This suggests that foraging, habitat use and the presence of large predators may be the drivers of sociality in otters. We conclude that most otters have a greater social potential than previously assumed, which is confirmed by their various vocalizations recently described.
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13

Longmire, KS, RD Seitz, A. Smith e RN Lipcius. "Saved by the shell: Oyster reefs can shield juvenile blue crabs Callinectes sapidus". Marine Ecology Progress Series 672 (19 agosto 2021): 163–73. http://dx.doi.org/10.3354/meps13781.

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Juvenile blue crabs Callinectes sapidus use seagrass and other structured habitats as refuges from predation. Oyster reef habitats provide structural complexity that may offer refuge, but the value of these habitats for juvenile blue crabs has not been examined. We quantified survival of juvenile C. sapidus in structured oyster reef habitat versus unstructured soft-bottom habitat. In a field tethering experiment in the York River, lower Chesapeake Bay (USA), juvenile C. sapidus (10-50 mm carapace width [CW]) were tethered in sand (n = 40) or oyster reef (n = 39) habitats at subtidal sites 1-2 m deep. An underwater camera system was used to record predation activity during 24 h trials. Juvenile crab survival was significantly higher on the oyster reef habitat (53.8%) than on bare sand (15.0%), and tended to increase with crab CW in both habitats. The main successful predators on juvenile blue crabs were northern pufferfish Sphoeroides maculatus in the oyster reef habitat and adult blue crabs in the sand habitat. The high survival rate of juvenile C. sapidus in oyster reef habitats suggests that oyster reefs include physical habitat complexity that may offer refuge from predators. Restored and natural oyster reefs could provide an alternative nursery habitat for juvenile blue crabs, expanding the ecosystem services provided by restored oyster reefs.
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14

Manzur, Tatiana, Mario Barahona e Sergio A. Navarrete. "Ontogenetic changes in habitat use and diet of the sea-star Heliaster helianthus on the coast of central Chile". Journal of the Marine Biological Association of the United Kingdom 90, n. 3 (19 ottobre 2009): 537–46. http://dx.doi.org/10.1017/s0025315409990786.

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Ontogenetic shifts in habitat use and diet are ubiquitous in nature and usually have profound consequences for the ecology and evolution of the species. In the case of species with strong interactions within their communities, such as keystone predators, understanding this kind of size-related change is critical to understand variation and connectivity among spatially distinct habitats of coastal communities. Yet the ecology of early life stages of marine benthic invertebrates, particularly asteroids, is poorly understood. Here we describe the results of surveys to characterize the habitat and quantify the abundance and diet of recruits of the sun star Heliaster helianthus, a keystone predator at rocky intertidal sites in central Chile. Our results support the existence of size-related, ontogenetic changes in habitat use and diet of this species. Recruits occupy boulders and crevices in the high or mid-high intertidal zones of wave-protected habitats and as they grow they move down towards lower tidal levels. Adults are characteristically found in the low intertidal zone of wave exposed and semi-exposed habitats. These changes in habitat use are accompanied by changes in diet composition and particularly by a broadening of the prey species incorporated in the diet. Since early stages of Heliaster appear to be most sensitive to predation and abiotic stress and since adults are such important predators in wave exposed rocky shores, knowledge of the basic ecology of early stages of this species is critical to fully understand the dynamics of intertidal communities.
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15

Lakhani, Leena, Dilip Soni e Brahmadeep Alune. "DANGERS OF PESTICIDES ON WILDLIFE ECOLOGY". International Journal of Research -GRANTHAALAYAH 3, n. 9SE (30 settembre 2015): 1–3. http://dx.doi.org/10.29121/granthaalayah.v3.i9se.2015.3205.

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Wildlife includes plants, insects, fish, amphibians, reptiles, birds and mammals and many other animals. Each species has certain niche for its specific food, shelter and breeding site. The place where specie has all of its living requirements becomes that species habitat. The wild life habitats include native and man-made, exist in urban settings, in agricultural fields and in the wilderness. Pesticides applied in many forms to forests, rangeland, aquatic habitats, farmland, urban turf and gardens. Pesticides poisoning to wildlife may result from acute or chronic exposure, via secondary exposure or through indirect effects to the animal.
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Peterson, Mark S., e Michael J. Andres. "Progress on Research Regarding Ecology and Biodiversity of Coastal Fisheries and Nektonic Species and Their Habitats within Coastal Landscapes". Diversity 13, n. 4 (15 aprile 2021): 168. http://dx.doi.org/10.3390/d13040168.

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This paper aims to highlight the new research and significant advances in our understanding of links between coastal habitat quality/quantity/diversity and the diversity of fisheries species and other mobile aquatic species (hereafter nekton) that use them within coastal landscapes. This topic is quite diverse owing to the myriad of habitat types found in coastal marine waters and the variety of life history strategies fisheries species and nekton use in these environments. Thus, we focus our review on five selective but relevant topics, habitat templates, essential fish habitat, habitat mosaics/habitat connectivity, transitory/ephemeral habitat, and the emerging/maturing approaches to the study of fish-habitat systems as a roadmap to its development. We have highlighted selected important contributions in the progress made on each topic to better identify and quantify landscape scale interactions between living biota and structured habitats set within a dynamic landscape.
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17

Fairbairn, D. J. "Comparative ecology of Gerris remigis (Hemiptera: Gerridae) in two habitats: a paradox of habitat choice". Canadian Journal of Zoology 63, n. 11 (1 novembre 1985): 2594–603. http://dx.doi.org/10.1139/z85-388.

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This study compares the population ecology of Gerris remigis (Hemiptera: Gerridae) in two habitats: a cool mountain stream, representing the characteristic habitat of this species, and the atypical habitat of a small, warm pond. Neither habitat supported breeding populations of any other gerrid species. The populations on the two sites were found to differ significantly with respect to population dynamics, dispersal, phenology, and wing dimorphism. Overall, the population on the pond was more productive than that on the stream, indicating that G. remigis can be highly successful in a warm, lentic habitat, in the absence of competing species. However, in spite of this success, adult G. remigis actively avoided the lentic site. Thus habitat choice in this species cannot be mediated solely by interspecific competition. Comparisons of the two sites suggest that current, temperature, and (or) shelter from direct sunlight and wind may act as proximate cues for habitat choice in this species. The striking differences between the two study populations are also evidence of a very high degree of phenotypic plasticity, which allows G. remigis to respond to differences in habitat characteristics on a very fine scale.
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18

Lyons, Melinda D., e Daniel L. Kelly. "Plant community ecology of petrifying springs (Cratoneurion) – a priority habitat". Phytocoenologia 47, n. 1 (1 gennaio 2017): 13–32. http://dx.doi.org/10.1127/phyto/2016/0101.

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19

Lodé, Thierry. "Habitat Selection and Mating Success in a Mustelid". International Journal of Zoology 2011 (2011): 1–6. http://dx.doi.org/10.1155/2011/159462.

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Habitat selection remains a poorly understood ecological process, but relating mating behaviour to pattern of habitat selection constitutes a fundamental issue both in evolutionary ecology and in biological conservation. From radiotelemetry protocol, habitat-induced variations in mating success were investigated in a solitary mustelid carnivore, the European polecatMustela putorius. Selection for marshy habitat was regarded as adaptive in that mating success was found greater using marches than other habitats. Males consorted with 1.3 females, revealing a low polygyny rate. Pregnant or lactating females selectively shifted to deciduous woods. That some habitat types may favour a good reproduction forms a key factor for species conservation and environmental management. Nevertheless, such as in various vertebrates, habitat requirements seem to be based on simple broad features of habitat, suggesting that habitat avoidance rather than habitat preference can explain polecat habitat predilection.
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20

Tyser, Robin. "Ecology of Fescue Grasslands in Glacier National Park". UW National Parks Service Research Station Annual Reports 13 (1 gennaio 1989): 61–64. http://dx.doi.org/10.13001/uwnpsrc.1989.2783.

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Fescue grasslands are small, but ecologically significant, habitat types in several drainages within Glacier Park. An up-to-date, systematic study of the plant and animal communities of these grasslands is needed to assess factors which may potentially impact these habitats, including invasion of exotic vegetation, fire suppression, and human development (e.g. sewage line and road construction).
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21

Noguchi, Hideyuki, Akira Itoh, Takashi Mizuno, Kriangsak Sri-ngernyuang, Mamoru Kanzaki, Sakhan Teejuntuk, Witchaphart Sungpalee et al. "Habitat divergence in sympatric Fagaceae tree species of a tropical montane forest in northern Thailand". Journal of Tropical Ecology 23, n. 5 (16 agosto 2007): 549–58. http://dx.doi.org/10.1017/s0266467407004403.

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Abstract (sommario):
Spatial distributions of many tropical trees are skewed to specific habitats, i.e. habitat specialization. However, habitats of specialist species must be divergent, i.e. habitat divergence, to coexist in a local community. When a pair of species specialize in the same habitat, i.e. habitat convergence, they could not coexist by way of habitat specialization. Thus, analyses of habitat divergence, in addition to habitat specialization, are necessary to discuss coexistence mechanisms of sympatric species. In this study, the habitat specialization and habitat divergence along topographic gradients of eight sympatric tree species of the Fagaceae were studied in a 15-ha study plot in a tropical lower montane forest in northern Thailand. A statistical test with torus shift randomizations for 9673 trees of Fagaceae revealed significantly biased distributions for all of the species, for at least one of the four topographic variables used: elevation, slope inclination, aspect and convexity. Slope convexity was the most critical topographic variable, along which all but one species had significantly skewed distributions. Out of 112 possible combinations of species pairs and topographic variables, 18 (16%) and two pairs (1.8%) showed significant habitat divergence and habitat convergence, respectively. The observed habitat divergence alone could not completely explain the coexistence of the eight species. There was a gradation in the habitat position of each species, with relatively large overlaps between species distributed in similar habitats, and small overlaps between species associated with contrasting habitats, respectively. The gradual changes in the habitats of the species suggested that dividing the species into a small number of distinct habitat groups, such as ridge and valley specialists, would not be straightforward.
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Peck, Lloyd S. "Ecology of Articulated Brachiopods". Paleontological Society Papers 7 (novembre 2001): 171–84. http://dx.doi.org/10.1017/s1089332600000954.

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Ecology is the study of the relationships between organisms and their environments. For brachiopods living in marine habitats the main external factors of interest are temperature, water chemistry, light characteristics, and oxygen availability. However, organisms also modify their environments and in many cases the biotic environment may dictate changes or organism responses. Factors of importance here for animals are resources consumed (usually food items), predators that consume the species under study, organisms that compete for resources, organisms that provide benefits such as symbiotic arrangements or new habitat for colonisation, and those organisms which reduce the quality of the environment such as pathogens or parasites.
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Vasconcelos, Rita P., David B. Eggleston, Olivier Le Pape e Ingrid Tulp. "Patterns and processes of habitat-specific demographic variability in exploited marine species". ICES Journal of Marine Science 71, n. 3 (7 settembre 2013): 638–47. http://dx.doi.org/10.1093/icesjms/fst136.

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Abstract Population dynamics are governed by four demographic rates: births, deaths, immigration, and emigration. Variation in these rates and processes underlying such variation can be used to prioritize habitat conservation and restoration as well as to parameterize models that predict habitat-specific effects on population dynamics. The current understanding of patterns of habitat-specific demographic variability in exploited marine species, as well as processes underlying these patterns, was reviewed. We describe patterns of (i) habitat-specific density, followed by ontogenetic changes in habitat use, such as (ii) immigration (i.e. use as a settlement habitat) and (iii) emigration (i.e. use as a habitat for secondary dispersal to and from), and demographic rates such as (iv) growth, and (v) mortality. Despite the importance of coastal habitats for fish and invertebrate species and the vulnerability of these habitats to human impacts, there was ambiguous evidence on their role in driving of population dynamics. Roughly 63% of the studies were descriptive, 21% experimental, and 11% used a combination of descriptive and experimental approaches, whereas 5% used meta-analyses. Habitat-specific density was the most common pattern quantified, followed by growth and mortality, with relatively few examples of studies of habitat-specific larval settlement. There were many examples of the influence of coastal habitats on survival, growth, and movement, especially at young stages, and there was an emerging focus on the effects of habitat degradation on demographic rates. There needs to be an increased effort on quantifying habitat-specific demographic rates and integrating these to better predict the effects of coastal habitats on the dynamics of exploited marine populations.
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M. Date, E., H. F. Recher, H. A. Ford e D. A. Stewart. "The conservation and ecology of rainforest pigeons in northeastern New South Wales". Pacific Conservation Biology 2, n. 3 (1995): 299. http://dx.doi.org/10.1071/pc960299.

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Abstract (sommario):
A survey of conservation reserves, rainforest remnants and agricultural districts in northeastern New South Wales was conducted to determine the abundance, movements and habitat requirements of rainforest pigeons, to evaluate the extent and use of suitable habitat in conservation reserves, and to provide guidelines for the conservation and management of rainforest pigeons. Eight species of rainforest pigeon occur in northeastern New South Wales. Commencing with the clearing of rainforest in the 1860s for agriculture, rainforest pigeons declined in abundance throughout New South Wales and by the 1970s five species were thought to be threatened in the state. Since then, rainforest pigeons have apparently increased in abundance and distribution, but the Wompoo, Rose-crowned and Superb Pigeons continue to be listed by the New South Wales National Parks and Wildlife Service as vulnerable and rare. However, populations of all species of rainforest pigeons in New South Wales are relatively small and vulnerable to further loss of habitat. Most rainforest pigeons show a preference for subtropical rainforest habitat, but moist eucalypt forests, gardens and weedy exotic vegetation along roads and on abandoned farmland are also frequented to varying degrees by different species. To investigate recent trends in pigeon abundance we used data collected for up to 12 years from eight sites and during 1988, 1989 and 1990 from 17 rainforest remnants in northeastern New South Wales. The data suggest that rainforest pigeons now occur more frequently in lowland agricultural areas than in the recent past and tend to confirm an increase in abundance since the 1970s. Nesting and foraging habitats for rainforest pigeons are extensive in the conservation reserve system of northeastern New South Wales, but these habitats, which are largely at high elevations, lack winter food resources. Instead, pigeons congregate in remnant rainforest and exotic berry-bearing trees and shrubs in agricultural areas at lower elevations and near the coast. They rely on these habitats for food during winter and it is the restricted extent of this habitat that probably limits their abundance, not the area or quality of habitat at higher elevations. The conservation and management of rainforest pigeons requires the protection of low elevation and coastal rainforest remnants. As development of northeastern New South Wales proceeds, to avoid a decline in the abundances of rainforest pigeons it will be necessary to protect sclerophyll forest with native or exotic fruit bearing trees and shrubs and to extend the area of suitable habitat by the regeneration of rainforest and by the planting of native species used by pigeons as a food source. This will become increasingly important as the control and removal of exotic plants, such as Lantana Lantana camara and Camphor Laurel Cinnamonum camphora, on which some pigeons depend as a winter food source, becomes more successful.
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25

Seitz, Rochelle D. "Value of coastal habitats for exploited species: introduction to a theme set of articles". ICES Journal of Marine Science 71, n. 3 (marzo 2014): 636–37. http://dx.doi.org/10.1093/icesjms/fst180.

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Abstract (sommario):
Abstract Many exploited fish and invertebrate species use coastal habitats during one or more life-history stages as spawning, feeding, and nursery areas; yet, the value of these habitats has not been adequately characterized. As habitat availability can be a bottleneck for many populations, concerns about habitat effects on exploited species have been increasing. We have compiled nine articles presenting the state of knowledge and future research priorities regarding the importance of habitat for exploited species. Reviews from European habitats and several geographical locations throughout the United States demonstrate the influence of coastal habitats on survival, growth, and movement, especially during the early life-history stages, in a wide variety of species, spatial scales, and habitats. Moreover, many of these species contribute substantially to commercial landings, highlighting the importance of coastal habitats to population persistence and fishery yields. Management of fishery species can also be enhanced through modelling efforts incorporating habitat. Finally, there is a need for more effort in quantifying population demographics rates, creating comprehensive habitat maps, and developing better census techniques for complex hard bottom habitats; thus, future work is needed on the value of coastal habitats for exploited species.
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26

Sundblad, Göran, Ulf Bergström, Alfred Sandström e Peter Eklöv. "Nursery habitat availability limits adult stock sizes of predatory coastal fish". ICES Journal of Marine Science 71, n. 3 (18 aprile 2013): 672–80. http://dx.doi.org/10.1093/icesjms/fst056.

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Abstract (sommario):
Abstract Habitat protection is a strategy often proposed in fisheries management to help maintain viable populations of exploited species. Yet, quantifying the importance of habitat availability for population sizes is difficult, as the precise distribution of essential habitats is poorly known. To quantify the contribution from coastal nursery habitats to exploited fish population sizes, we related adult density to the amount of nursery habitat available for 12 populations of the two dominant predatory fish species in a 40 000-km2 archipelago area of the Baltic Sea. Habitat distribution was mapped using three conceptually different techniques, Maxent, generalized additive models, and random forest, using spawning and 0-group point samples. Adult densities were estimated from gillnet surveys. Regressions demonstrated no evident effect from fishing, whereas habitat availability had a positive effect, explaining almost half of the variation in population sizes of both species. This result shows that a substantial proportion of the potential production of adult fish can be estimated by mapping essential nursery habitats distribution. Responses were non-linear, indicating that habitat protection has largest effects where there is little available habitat. By demonstrating the importance of habitat limitation of two exploited fish species, we provide quantitative support to the benefits of habitat protection for fisheries.
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27

Belovsky, Gary E. "Insights for caribou/reindeer management using optimal foraging theory". Rangifer 11, n. 4 (1 ottobre 1991): 7. http://dx.doi.org/10.7557/2.11.4.987.

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Abstract (sommario):
Optimal foraging theory is useful to wildlife managers, because it helps explain the nutritional value of different habitats for wildlife species. Based upon nutritional value, the use of different habitats can be predicted, including how factors such as insect harassment, predation and migration might modify habitat selection. If habitat value and use can be understood, then changes in habitat availability which are of concern to wildlife managers can be assessed. The theory is used to address diet choice and habitat use of caribou/reindeer. Diet choice is examined in terms of lichen composition of the diet and is demonstrated to be a function of daily feeding time, food abundance and digestive capacity. The diet choice model is then used to assess the nutritional profitability of different habitats and which habitat should be preferred based upon nutritional profitability. Caribou/reindeer use of habitats is demonstrated to be easily modified by insect harassment and predation which change the nutritional profitability of habitats differentially. The same type of approach could be used to explain migratory behaviour; however, the needed parameter values are unavailable. The results of this analysis lead one to question some common conceptions about caribou/reindeer ecology.
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28

BÎRSAN, Cipran, Ana COJOCARIU e Elena CENUŞĂ. "Distribution and Ecology of Clathrus archeri in Romania". Notulae Scientia Biologicae 6, n. 3 (22 settembre 2014): 288–91. http://dx.doi.org/10.15835/nsb639389.

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Abstract (sommario):
Although Clathrus archeri is a widely spread species in the Western Europe, in Romania it is considered a rare species, identified from only eight sites. In July 2013, it was found in two new sites from Gurghiu and Bârgău Mountains, in the Romanian Eastern Carpathians. This paper presents a detailed description of the new recorded specimens and of the habitat where this fungus was found. Plant communities where Clathrus archeri was recorded belong to the “mountain hay meadows” habitat type (Festuco rubrae - Agrostietum capillaris community). Taking into consideration the previous published data, the comparison with other habitats types in which this species occurs suggests that Clathrus archeri has no special preferences for certain environmental conditions.
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29

Hartung, Sarah C., e Jeffrey D. Brawn. "Effects of Savanna Restoration on the Foraging Ecology of Insectivorous Songbirds". Condor 107, n. 4 (1 novembre 2005): 879–88. http://dx.doi.org/10.1093/condor/107.4.879.

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Abstract (sommario):
Abstract We studied the foraging behavior of insectivorous songbirds during the breeding season at four sites in Illinois, each with restored open-canopy savanna habitat (65% mean canopy closure) and closed-canopy forests (89% mean canopy closure). We sampled and compared apparent tree species preference, foliage layer preference, and proportional use of different prey-attack maneuvers in the two habitats. In closed-canopy forests, three of nine songbird species foraged in black oak (Quercus velutina) and white oak (Q. alba) more than expected based on availability, and foraged less than expected in shade-tolerant trees such as sugar maple (Acer saccharum) and red elm (Ulmus rubra). Four species also displayed apparent preferences for black locust (Robinia pseudoacacia) and hackberry (Celtis occidentalis). In contrast, songbirds used tree species according to availability in open-canopy habitat. We observed apparent preferences for the shrub and subcanopy vegetation layers (0–5 m and 6–10 m) in open-canopy habitat and apparent preferences for the subcanopy and lower canopy vegetation layers (6–10 m and 11–15 m) in closed-canopy forests. Relative use of prey-attack maneuvers in open versus closed-canopy habitat was significantly different for the Eastern Wood-Pewee (Contopus virens) and the Great Crested Flycatcher (Myiarchus crinitus), but not for foliage-gleaning species. These results suggest that restoration of oak savannas has important effects on the habitat use and foraging ecology of selected insectivorous birds.
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30

Hanrahan, Alexander T., Andrew U. Rutter, Clayton K. Nielsen e Eric M. Schauber. "Spatial ecology of river otters in a human-modified landscape". Journal of Mammalogy 100, n. 4 (20 giugno 2019): 1327–39. http://dx.doi.org/10.1093/jmammal/gyz095.

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Abstract (sommario):
AbstractRiver otter populations have expanded across much of their historical range, including in Illinois where they were reintroduced from 1994 to 1997. These expanding populations are recolonizing a wide range of landscapes with different levels of human modification, which could influence how river otters use space in relation to habitat characteristics and each other. Our objectives were to quantify 1) home ranges and core areas, 2) sociality, and 3) habitat selection across all available habitats and within home ranges (second- and third-order selection, respectively) of 22 radiomarked river otters (Lontra canadensis) in southern Illinois during 2014–2016. Our study area contained a diverse mix of forest, agriculture, aquatic and wetland habitats, and a range of urban development intensity. We examined sociality using the frequency at which individuals were located < 25 m from a conspecific and compared home-range overlap among individuals based on sex. Habitat selection at the second and third order was analyzed using an eigen-analysis of selection ratios based on landcover categories. Similar to other studies, male river otters had > 2-fold larger home ranges and core areas than females in southern Illinois. Several lines of evidence indicated males were more social than females. Males were located close to a conspecific more frequently than were females, and overlap of home ranges and core areas among males was greater than it was among females or between sexes. As observed in other landscapes, river otters strongly selected herbaceous and wooded wetlands at both second- and third-order scales. River otters selected terrestrial cover types with vegetative cover potentially due to shelter or prey availability. Forests were selected over crop fields at the third-order scale, which was consistent with studies using sign surveys. River otters in our study had home ranges containing 0–40% developed land cover, but we found no evidence that otters living in more developed areas used their home ranges more selectively. River otters in this landscape were plastic in regard to social behavior and habitat selection, highlighting their generalist nature and providing insight into their ability to successfully recolonize areas of the Midwest with sufficient vegetative cover and aquatic habitat, among other factors.
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31

Krebs, Charles J. "Whither mammalian ecology?" Journal of Mammalogy 101, n. 5 (23 luglio 2020): 1224–30. http://dx.doi.org/10.1093/jmammal/gyaa072.

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Abstract (sommario):
Abstract The critical agenda for mammalian ecologists over this century is to obtain a synthetic and predictive understanding of the factors that limit the distribution and abundance of mammals on Earth. During the last 100 years, a start has been made on this agenda, but only a start. Most mammal species have been described, but there still are tropical areas of undisclosed species richness. We have been measuring changes in distribution and abundance of many common mammals during the last century, and this monitoring agenda has become more critical as climate change has accelerated and habitat destruction has increased with human population growth. There are a small number of factors that can limit the distribution and abundance of mammals: weather, predation, food supplies, disease, and social behavior. Weather limits distribution and abundance mostly in an indirect manner by affecting food supplies, disease, and predation in the short term and habitat composition and structure in the longer term. A good starting point for all studies of mammals is to define them within a well-structured trophic web, and then quantify the major linkages within that web. We still are far from having data on enough model systems to develop a complete theory and understanding of how food webs are structured and constrained as climate shifts and humans disturb habitats. We have many of the bits and pieces for some of our major ecosystems but a poor understanding of the links and the resilience of our mammalian communities to changes in trophic webs driven by climate change and human disturbances.
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32

Jayawardana, J. M. C. K., Martin Westbrooke, Michael Wilson e Cameron Hurst. "Macroinvertebrate communities in willow (Salix spp.) and reed beds (Phragmites australis) in central Victorian streams in Australia". Marine and Freshwater Research 57, n. 4 (2006): 429. http://dx.doi.org/10.1071/mf05139.

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Abstract (sommario):
Exotic willows (Salix spp.) are widespread riparian tree species of rivers in temperate Australia and New Zealand. Despite being considered as a weed of national significance, little is known about the habitat value of willows and the impact on aquatic biota of vegetation change following willow management programmes. Macroinvertebrate fauna in root habitats of willows and Phragmites australis habitats were examined in three central Victorian rivers to understand the effect of such littoral habitat changes on macroinvertebrates. Data were analysed using Partially Nested Factorial ANOVA with season, river and habitat as main effects. Habitat structure had a significant effect (P < 0.05) on macroinvertebrate community assemblage. However, effect of habitat was not consistent among seasons. The greatest community differences among habitats were observed during winter and least separation during autumn. Taxa responsible for community differences among habitats were also identified. Species richness and abundance did not show consistent variation among habitats over different rivers or seasons. This study provided some indication of the macroinvertebrate community changes that would take place in situations where riparian vegetation changes takes place from willows to P. australis.
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33

Guisan, Antoine, e Niklaus E. Zimmermann. "Predictive habitat distribution models in ecology". Ecological Modelling 135, n. 2-3 (dicembre 2000): 147–86. http://dx.doi.org/10.1016/s0304-3800(00)00354-9.

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34

O'CONNOR, R. J. "Avian Ecology: Habitat Selection in Birds." Science 230, n. 4728 (22 novembre 1985): 933. http://dx.doi.org/10.1126/science.230.4728.933.

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35

MILNER, ALEXANDER M., e GEOFFREY E. PETTS. "Glacial rivers: physical habitat and ecology". Freshwater Biology 32, n. 2 (ottobre 1994): 295–307. http://dx.doi.org/10.1111/j.1365-2427.1994.tb01127.x.

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36

Araújo, Luzia Márcia, e Geraldo Wilson Fernandes. "Altitudinal patterns in a tropical ant assemblage and variation in species richness between habitats". Lundiana: International Journal of Biodiversity 4, n. 2 (30 dicembre 2003): 103–9. http://dx.doi.org/10.35699/2675-5327.2003.21860.

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Abstract (sommario):
The distribution of ants along an altitudinal gradient from 800 m to 1500 m was studied in southeastern Brazil. Two hypotheses were tested: a) “the altitudinal gradient hypothesis”, which predicts that ant species richness decreases with increasing altitude; and b) “the habitat favourability hypothesis”, which predicts that ant species richness is higher in mesic habitats than in xeric habitats, independent of altitude. Pairs of mesic and xeric habitats were randomly established and replicated three times at each 100 m of elevation. Mesic habitats were those along washes, creeks and rivers while xeric habitats were those away from water resources. Ants were collected utilizing sardine baits distributed along transects on both vegetation and on soil. The species richness of ants collected on vegetation and soil increased with decreasing elevation. This pattern was found for ants collected on the ground in both mesic and xeric habitats. Also, we found more ant species in mesic habitats (0.64 ± 0.05 ants/sample set) than in xeric habitats (0.45 ± 0.05 ants/sample set)(t = 3.51, p < 0.001). The decreased number of ant species at higher elevations as well as in xeric habitats may be caused by a decrease in habitat complexity that limits the success of ants. Furthermore, at high altitudes harsher habitat conditions and lower temperatures prevail, further limiting the success and establishment of ants. Keywords: Altitudinal Gradients, Ants, Cerrado, Diversity, Habitat Complexity
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37

Crear, DP, RJ Latour, MAM Friedrichs, P. St-Laurent e KC Weng. "Sensitivity of a shark nursery habitat to a changing climate". Marine Ecology Progress Series 652 (15 ottobre 2020): 123–36. http://dx.doi.org/10.3354/meps13483.

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Abstract (sommario):
Nursery area habitats such as estuaries are vital for the success of many fish populations. Climate change is altering conditions in these areas, which can thus impact the availability of suitable nursery habitat. The sandbar shark Carcharhinus plumbeus uses Chesapeake Bay (USA) as a nursery habitat during the summer months from birth up to 10 yr of age. To assess the impacts of climate change on juvenile sandbar sharks, we developed a habitat model using longline data collected from a fishery-independent survey within Chesapeake Bay. With this model, we projected contemporary and future distributions of suitable habitat for juvenile sandbar sharks in Chesapeake Bay under varying environmental regimes. Predicted suitable juvenile sandbar shark habitat was negatively impacted by future increases in temperature, but positively influenced by future decreases in dissolved oxygen. The latter trend was likely related to the habitat partitioning that occurs between different life stages. Changes in salinity had relatively small impacts. By end-of-century the projected amount of suitable bottom habitat decreased; however, when incorporating the entire water column, projected suitable habitat increased. This suggests that juvenile sandbar sharks may need to make a behavioral shift to avoid non-preferred conditions, which could alter their foraging ecology or refuge strategies. As nursery habitats change with climate change, it is crucial to understand how a species may be impacted during this vital life stage when trying to predict overall species success in the future.
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38

Rosenfeld, Jordan S., e Todd Hatfield. "Information needs for assessing critical habitat of freshwater fish". Canadian Journal of Fisheries and Aquatic Sciences 63, n. 3 (1 marzo 2006): 683–98. http://dx.doi.org/10.1139/f05-242.

Testo completo
Abstract (sommario):
The core assumptions of critical habitat designation are a positive relationship between habitat and population size and that a minimum habitat area is required to meet a recovery target. Effects of habitat on population limitation scale from (i) effects on performance of individuals (growth, survival, fecundity) within a life history stage, to (ii) limitation of populations by habitats associated with specific life history stages, and (iii) larger-scale habitat structure required for metapopulation persistence. The minimum subset of habitats required to achieve a recovery target will depend on the extent, quality, and spatial configuration of habitats available to sequential life history stages. Although populations may be limited by available habitat for a single life history stage, altering habitat quality for subsequent stages will also affect individual survival and population size, providing multiple leverage points within a life history for habitat management to achieve recovery targets. When habitat-explicit demographic data are lacking, consequences of uncertainty in critical habitat assessment need to be explicit, and research should focus on identifying habitats most likely to be limiting based on species biology.
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39

Pratt, Thomas C., e Karen E. Smokorowski. "Fish habitat management implications of the summer habitat use by littoral fishes in a north temperate, mesotrophic lake". Canadian Journal of Fisheries and Aquatic Sciences 60, n. 3 (1 marzo 2003): 286–300. http://dx.doi.org/10.1139/f03-022.

Testo completo
Abstract (sommario):
Compensation measures in response to Fisheries and Oceans Canada (DFO) Policy for the Management of Fish Habitat includes provisions for habitat creation and enhancement. Thus, an assessment of nearshore habitat utilization patterns by fishes is needed to put DFO compensation measures in the context of the "no net loss of the productive capacity of fish habitat" directive. Measures of abundance, richness, and diversity of fishes were compared across nine habitat types in a lake using rapid visual underwater assessment. Multivariate analyses separated habitats into three groups and identified two distinct species assemblages. Most species were associated with macrophytes, but a few were primarily associated with rocky substrate. Shallow mud (open) habitats contained significantly fewer species and had lower mean scores and diversity than all other habitat types. Rocky habitats had lower mean scores and diversity than some vegetated habitat types containing similar fish assemblages. Surprisingly, within-site fish assemblage heterogeneity was similar to among-site heterogeneity, and among-habitat heterogeneity was lower than within-habitat heterogeneity, further supporting our inability to distinguish among vegetated habitat types. Our results suggest that habitat heterogeneity is critical in maintaining diverse communities and that compensation measures should account for differences in fish–habitat associations among varied habitats.
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40

Rosenzweig, Michael L. "Reconciliation ecology and the future of species diversity". Oryx 37, n. 2 (aprile 2003): 194–205. http://dx.doi.org/10.1017/s0030605303000371.

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Abstract (sommario):
Species-area relationships (SPARs) dictate a sea change in the strategies of biodiversity conservation. SPARs exist at three ecological scales: Sample-area SPARs (a larger area within a biogeographical province will tend to include more habitat types, and thus more species, than a smaller one), Archipelagic SPARs (the islands of an archipelago show SPARs that combine the habitat-sampling process with the problem of dispersal to an island), and Interprovincial SPARs (other things being equal, the speciation rates of larger biogeographical provinces are higher and their extinction rates are lower, leading to diversities in proportion to provincial area). SPARs are the products of steady-state dynamics in diversity, and such dynamics appears to have characterized the earth for most of the last 500 million years. As people reduce the area available to wild species, they impose a linear reduction of the earth's species diversity that will follow the largest of these scales, i.e. each 1% reduction of natural area will cost about 1% of steady-state diversity. Reserving small tracts of wild habitat can only delay these reductions. But we can stop most of them by redesigning anthropogenic habitats so that their use is compatible with use by a broad array of other species. That is reconciliation ecology. Many pilot projects, whether intentionally or inadvertently espousing reconciliation ecology, are demonstrating that it can be done.
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41

Hazell, Donna. "Frog ecology in modified Australian landscapes: a review". Wildlife Research 30, n. 3 (2003): 193. http://dx.doi.org/10.1071/wr02075.

Testo completo
Abstract (sommario):
Frog decline in Australia has often occurred where habitat is relatively intact. Habitat alteration and loss do, however, threaten many species. Widespread degradation of aquatic and terrestrial systems has occurred since European settlement, with only 6.4% of Australia's landmass reserved for conservation. But what do we know about how frogs use modified Australian landscapes? Do wildlife managers have the information required to ensure that frog habitat is considered in the management and revegetation of these areas? This review examines published Australian research on frogs to determine knowledge on processes of habitat loss and degradation. Literature that informs landscape restoration and revegetation is also examined to determine whether the habitat needs of frogs are considered. While many threats associated with frog habitat loss and change have been identified there is little quantitative information on frog–habitat relationships in modified landscapes, habitat fragmentation or knowledge of the connectivity required between terrestrial and aquatic frog habitat. Without this information frogs have largely been ignored in efforts to revegetate and manage for the conservation of Australian biota outside reserves. Ecological frog research in modified landscapes is required to avoid land-management decisions and conservation strategies based on inappropriate assumptions of how biota respond to landscape change.
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42

Sá, Amanda Aciely Serafim de, Ramon Pereira da Silva, Francisca Xavier Quintino Neta, Valeska Cristina Souza Silva de Assis, Jaiara Almeida de Oliveira, Gustavo Henrique de Oliveira, Cíntia da Silva de Oliveira e Ednaldo Candido Rocha. "Análise bibliométrica da produção científica sobre a hipótese da quantidade de habitat". OBSERVATÓRIO DE LA ECONOMÍA LATINOAMERICANA 22, n. 7 (25 luglio 2024): e5995. http://dx.doi.org/10.55905/oelv22n7-270.

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Abstract (sommario):
A Hipótese da Quantidade de Habitat (Habitat Amount Hypothesis) é um tema recente na ecologia de paisagens, e pressupõe que a quantidade de habitat em uma paisagem local é o principal determinante da riqueza de espécies. A análise das publicações científicas sobre esse tema pode orientar futuros trabalhos. O objetivo desse trabalho foi fazer uso dessa ferramenta de análise bibliométrica para compreender a evolução bibliométrica do tema Hipotese da Quantidade de Habitat. Este estudo utilizou a análise bibliométrica, uma metodologia quantitativa, para identificar o volume e o padrão de crescimento da literatura nesta área emergente. Os dados bibliométricos foram obtidos nas bases de dados Scopus e Web of Science, utilizando as expressões: “Habitat amount (hypothesis habitat amount) and Landscape ecology (habitat fragmentation) or Biodiversity of fragmented areas”. Foram encontrados 90 artigos sobre o tema entre 2002 e 2022. Lenore Fahrig destaca-se como a pesquisadora mais influente sobre a Hipótese da Quantidade de Habitat. Embora as pesquisas tenham aumentado ao longo do tempo, o tema ainda é tratado de forma incipiente, considerando a importância do estudo da ecologia de paisagens.
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43

Bjørge, Arne. "The harbour porpoise (Phocoena phocoena) in the North Atlantic: Variability in habitat use, trophic ecology and contaminant exposure". NAMMCO Scientific Publications 5 (1 luglio 2003): 223. http://dx.doi.org/10.7557/3.2749.

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Abstract (sommario):
Harbour porpoises inhabit coastal waters, in habitats that are characterized by high diversity and complexity in terms of their bathymetry, substrate, fish communities and point sources of contaminants. The complexity in these habitats influences both the habitat use and feeding ecology of porpoises. Congregations of porpoises feeding primarily on one species are observed in some areas and seasons, while wide movements and diets composed of several species are observed in other areas. Due to these observations, this paper suggests that caution is needed when extrapolatingknowledge from one area to another with regard to porpoise habitat use, exposure to contaminants, and interactions with fisheries. Management plans should be site specific and based on local knowledge incorporating porpoise population structure, habitat use, and multiple environmental factors in order to ensure appropriate conservation of this abundant but still vulnerable small cetacean species.
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44

McLeod, S. R., e A. R. Pople. "Modelling the distribution and relative abundance of feral camels in the Northern Territory using count data". Rangeland Journal 32, n. 1 (2010): 21. http://dx.doi.org/10.1071/rj09057.

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Abstract (sommario):
The objectives of this study were to predict the potential distribution, relative abundance and probability of habitat use by feral camels in southern Northern Territory. Aerial survey data were used to model habitat association. The characteristics of ‘used’ (where camels were observed) v. ‘unused’ (pseudo-absence) sites were compared. Habitat association and abundance were modelled using generalised additive model (GAM) methods. The models predicted habitat suitability and the relative abundance of camels in southern Northern Territory. The habitat suitability maps derived in the present study indicate that camels have suitable habitat in most areas of southern Northern Territory. The index of abundance model identified areas of relatively high camel abundance. Identifying preferred habitats and areas of high abundance can help focus control efforts.
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45

Caddy, John F. "Why do assessments of demersal stocks largely ignore habitat?" ICES Journal of Marine Science 71, n. 8 (19 aprile 2013): 2114–26. http://dx.doi.org/10.1093/icesjms/fss199.

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Abstract (sommario):
AbstractThe divergence between most stock assessments and studies in marine ecology is characterized by the low priority usually given to assessing the holding capacity of marine habitats. Habitats of high structural complexity are relatively uncommon in shelf waters, are contagiously distributed, and are damaged incidentally by bottom-towed gear. Structurally complex habitats are used by many demersal fish and crustaceans for predation abatement and as a site for feeding forays. Successive life-history stages typically migrate through several structurally complex habitats which recent studies show often to have fractal properties. One consequence of fractal structures as cover is a rapid reduction of protection from predators with growth in size: migration is the only response possible when further growth of the recruiting age class renders individuals in that habitat vulnerable to predation. A common feature of structurally complex habitats with high vulnerability at size is the occurrence of population bottlenecks. It is suggested that identifying and rectifying shortages of structured habitat, and eliminating habitat bottlenecks, will be effective in stock enhancement. This will require placing strict spatial constraints on the operation of bottom gear. This paper reviews new methods of estimating juvenile predation mortality, including mortality-at-age and mortality-at-life-history stage, which depend on the fractal characteristics of structurally complex habitats.
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46

Johnston, Gerald R., Eric Suarez, Joseph C. Mitchell, Georgia A. Shemitz, Peter L. Butt e Matthew Kaunert. "Population ecology of the snapping turtle (Chelydra serpentina osceola) in a northern Florida river". Bulletin of the Florida Museum of Natural History 51, n. 4 (10 agosto 2012): 243–56. http://dx.doi.org/10.58782/flmnh.enxa4516.

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Abstract (sommario):
Snapping turtles (Chelydra serpentina) occur in nearly every type of freshwater habitat in North America east of the Rocky Mountains, but little is known about the ecology of populations in the southern part of their range, as well as those in lotic habitats. We conducted a mark-recapture study of the Florida snapping turtle (C. s. osceola) in the Santa Fe River in northern Florida between August 2005 and November 2010. Ninety-six percent of all captures occurred within a 9 km section of the river that receives direct input from 21 artesian springs. Within this “high density spring area,” population density and biomass of adults were 2.7 turtles/ha and 24.9 kg/ha, respectively. The total sample (n = 113 turtles) consisted of 14.2% immature individuals, 45.1% adult females, and 40.7% adult males. Adult sex ratio was 1:1. Juveniles occupied spring and spring run habitats disproportionally to the river habitat. Adult males (straight midline carapace length [CL] 243–439 mm, mean = 360 mm) are the largest known in Florida, and adult females (CL 257–380 mm, mean = 325 mm) are similar in size to the largest known conspecifics in Nebraska and South Dakota. The large body sizes in our population are inconsistent with previous studies that indicate a positive relationship between body size and latitude in this species, emphasizing the importance of habitat type in influencing demography. Large body sizes in the Santa Fe River may be related to the thermal/food resources provided by artesian springs, the physical environment of the riverine habitat, or coexistence with alligator snapping turtles (Macrochelys temminckii).
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47

Virgl, John A., e François Messier. "Assessment of source-sink theory for predicting demographic rates among habitats that exhibit temporal changes in quality". Canadian Journal of Zoology 78, n. 8 (1 agosto 2000): 1483–93. http://dx.doi.org/10.1139/z00-066.

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Abstract (sommario):
Within the framework of Pulliam's source-sink model we tested predictions of habitat-specific demography on a "closed" population of muskrats (Ondatra zibethicus L.) occupying three contiguous habitats that exhibited temporal changes in quality and quantity. We were able to distinguish between dispersal among habitats and mortality within each habitat, and induce temporal variation in operational-habitat availability and suitability by manipulating water level. Temporal variation in population size and density among habitats supported the source-sink model and was primarily associated with habitat-specific survival rates. For example, the mean annual over-winter mortality rate of individuals in the principal source habitat (0.87) was less than in the sink habitat (0.94), and subsequently the mean annual finite rate of increase (λ) was positive in the source habitat (λ = 1.41) and negative in the sink habitat (λ = 0.90). The high recruitment rate of juveniles in the prime habitat during autumn was also associated with significant emigration of juveniles from this habitat. Emigration of adults among habitats provided support for the role of spacing behaviour in regulating the breeding density of muskrats in prime habitat. However, in contrast to the assumption of source-sink theory, year-to-year variation in survival rate in the more marginal habitats appeared to be explained more by temporal changes in habitat suitability than by density. Significant emigration of juveniles from the sink habitat was not predicted and was largely dependent on current habitat conditions. In addition, the mean annual emigration rate was lowest in the principal source habitat (0.30) and highest in the more marginal habitats (0.62). Failure to detect directional emigration from prime to marginal habitats in the spring, as predicted by the source-sink model, was likely due to declining local population size. In environments where spatial differences in habitat quality are not static, and annual change in local population size is largely independent of density, current source-sink models must be modified to better predict individual dispersal strategies.
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48

Ross, P. M., S. F. Thrush, J. C. Montgomery, J. W. Walker e D. M. Parsons. "Habitat complexity and predation risk determine juvenile snapper (Pagrus auratus) and goatfish (Upeneichthys lineatus) behaviour and distribution". Marine and Freshwater Research 58, n. 12 (2007): 1144. http://dx.doi.org/10.1071/mf07017.

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Abstract (sommario):
Early research into the distribution of juvenile snapper (Pagrus auratus) indicated that complex habitats were not important during early life stages. Recent studies in soft-sediment environments, however, have shown juvenile snapper to be more abundant in areas of complex habitat. No previous studies have investigated how and why this species uses both reef and soft-sediment habitats. Therefore, we examined the role of topographic complexity in influencing juvenile snapper distribution and habitat use, providing both field and laboratory evidence for the importance of complex benthic habitats for juvenile snapper and goatfish (Upeneichthys lineatus). Underwater visual censuses showed both species to be most abundant over sand flats adjacent to rocky reef habitats, a distribution that may balance the requirements of food acquisition and predator avoidance. In aquaria experiments, where juvenile snapper were given a choice between habitat with and without shelter, the use of shelter habitat increased significantly in the presence of a predatory threat. This demonstration of the use of complex habitat as shelter highlights the importance of benthic complexity for juvenile snapper and suggests that the management of essential habitats could enhance juvenile survivorship and should have an important role to play in sustainable management of exploited species.
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49

Stephenson, Fabrice, Nicholas V. C. Polunin, Aileen C. Mill, Catherine Scott, Paula Lightfoot e Clare Fitzsimmons. "Spatial and temporal changes in pot-fishing effort and habitat use". ICES Journal of Marine Science 74, n. 8 (28 aprile 2017): 2201–12. http://dx.doi.org/10.1093/icesjms/fsx051.

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Abstract (sommario):
Abstract Habitat and fisheries usage data are key components for ecosystem-based approach to fisheries management (EBFM). Significant gaps in knowledge remain for fisheries–habitat interactions, particularly in inshore fisheries where vessels are &lt;12 m in length. Here, we show changes in inshore fishing effort distribution (&lt;12 m) and habitat use over the decade 2004–2013. Sightings data of fishing vessel activity recorded by the Northumberland Inshore Fishery and Conservation Authority (NIFCA) were combined with landings data to estimate and map pot-fishing activity between 2004 and 2013. Spatial temporal changes were investigated using Monte Carlo simulation of randomly sampled fishing effort maps. High resolution (1 m) broadscale (EUNIS level 3) predictive habitat maps of the Coquet to St Marys’ Marine Conservation Zone (CQSM MCZ) were used to investigate spatial temporal changes in fishers’ habitat selection using compositional analysis. Fishing effort in Northumberland increased between 2004 and 2013 (233 642–354 193 pots year−1). Fishing effort distribution differed between individual years, decreasing over large areas between 2004 and 2007, followed by increases, especially inshore, between 2008 and 2013. Fishers in the CQSM MCZ showed a preference for rocky habitats over sediment habitats. Habitat preference did not vary between years although all habitats experienced increasing fishing pressure. Spatial temporal changes in fishing effort and habitat use were discussed in relation to EBFM.
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50

Gulati, Harsh, e Sarita Rana. "Habitat Preference and Current Threats to The Sarus Cranes Grus Antigone (Aves: Gruiformes: Gruidae) In Important Bird Areas of Haryana, India: Implications for Determining Effective Conservation Actions". Journal of Advanced Zoology 43, n. 1 (17 ottobre 2022): 07–16. http://dx.doi.org/10.17762/jaz.v43i1.110.

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Abstract (sommario):
Understanding the habitat preferences of Sarus Crane can assist ecologists in identifying high-priority habitats and improving conservation strategies. The habitat utilization and preference of Sarus Crane were studied in and around Important Bird areas of the Gurugram district from November 2019 to October 2020. In total, 171 flocks were observed in agricultural land followed by marshland (147) and grassland (11). Our analysis showed that the Sarus Crane strongly preferred agricultural areas (s = +0.18) and avoided grassland habitats (s = -0.22 and -0.53 respectively). There was a significant difference in the utilization of agriculture and marshland (P<0.05) habitats in different seasons. However, the Sarus Crane utilized the grassland habitat randomly (P>0.05). The Sarus Cranes experienced several serious threats, including predation, habitat destruction, and the agricultural use of pesticides. This study on habitat preference and current threats will provide a scientific baseline for future research to better understand the ecology of the Sarus Cranes and will be helpful in their conservation. These IBA’s are the only suitable sites in Haryana because it is surrounded by a large area of agricultural land and exposed to the pressure of human activities. It is, therefore, necessary to protect such habitats, to provide a healthy ecosystem for Sarus Cranes.
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