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The role of biotic resistance through predation on the invasion success of the green porcelain crab (Petrolisthes armatus) into nearshore oyster reef communities.Kinney, Kaitlin Alyse January 2017 (has links)
No description available.
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Risk-Sensitive Foraging Facilitates Species-Level Trophic Cascades Among Terrestrial Mammals: A Meta-AnalysisMurray, Bryan David 30 September 2009 (has links)
No description available.
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Honey bee landscape ecology: foraging, toxic exposure, and apicultural outcomesSponsler, Douglas B. January 2016 (has links)
No description available.
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Design and Analysis of Optimal Task-Processing AgentsPavlic, Theodore Paul 22 October 2010 (has links)
No description available.
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Foraging In Times of Crises : A Feminist Exploration of Narratives of Nature, Identity, and Environmental Engagement in the Practice of Foraging in the Swedish ContextIsabella, Guabello January 2024 (has links)
Using a mixed methods approach informed by feminist and gender studies methodologies, this thesis explores foraging in Sweden as a socio-cultural practice, examining its relevance in narratives of identity, belonging, space, and environmental engagement amid contemporary ecocrises. The material used is nearly two hundred responses from a questionnaire, distributed to members of Swedish Facebook foraging groups, and five qualitative semi-structured interviews. The analysis shows that foraging appears to be part of national representations of nature, connecting to discourses of Swedish/Nordic exceptionalism. Foraging narratives shape understandings of nature, particularly in relation to Swedish landscapes, and inform current conflicts in the forests. Clear-cut forestry practices erase cherished foraging spots, lead wider reflections on capitalist-driven ecological crises and trigger feeling of loss and grief in foragers. These experiences foster a deeper awareness of environmental challenges and lead to subtle, routine practices of ‘soft activism’ as a form of gentle response. Analysing foraging from a feminist environmental perspective opens up opportunities to look at how discourses on nature influence identity formation, but also create cracks in dominant narratives. Although foraging has been coopted in processes of national identity reproduction, it also functions as a catalyst to trigger ecological awareness and sustains individual practices, framed as soft resistance to neoliberal forces, nurturing forms of hope in the face of current multiple environmental crises.
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Spatial ecology and demography of eastern coyotes (Canis latrans) in western VirginiaMorin, Dana Janine 29 July 2015 (has links)
Coyote (Canis latrans) range expansion in the Central Appalachian Mountains has stimulated interest in ecology of this predator and potential impacts to prey populations. This is particularly true in the Ridge and Valley Region in western Virginia where white-tailed deer (Odocoileus virginianus) populations are restricted by low nutritional carrying capacity and are subject to two other predators, bobcats (Lynx rufus) and American black bears (Ursus americanus), in addition to an active hunter community. I address two primary objectives of the Virginia Appalachian Coyote Study: to investigate 1) spatial ecology and 2) population dynamics of coyote populations in Bath and Rockingham counties. I deployed 21 GPS satellite collars on 19 coyotes over 32 months. I estimated home range size (mean = 13.46 km², range = 1.23 km² - 38.24 km²) across months using biased-random bridges and second-order habitat selection at four scales using eigenanalysis of selection ratios. I developed a metric to classify social status of individuals as either resident or transient based on stability of home range centers over time. I found evidence for class substructure for selection of territories where adult residents had a higher probability of mortality in high productivity/high risk habitats, compared to subadults and transients that were restricted to less productive habitats. I collected scat samples over five scat surveys across 2.5 years and extracted fecal DNA to identify individual coyotes in a mark-recapture framework. I estimated coyote densities in Bath (5.53 – 9.04 coyotes/100 km²) and Rockingham Counties (2.41 – 8.53 coyotes/100 km²) using a spatial capture-recapture model. Six-month apparent survival was lower in Bath County (Φ<sub>Bath</sub> = 0.442, 0.259 – 0.643; Φ<sub>Rockingham</sub> = 0.863, 0.269 – 0.991). The Bath County population demonstrated persistence despite high mortality and the Rockingham population demonstrated boundedness with recruitment inverse of changes in density. Findings at both sites suggest density-dependence, and tests of territoriality, presence of transients, and territory turnover demonstrate a capacity for immediate local immigration in response to high mortality in Bath County. I suggest that landscape-level habitat management may be a viable strategy to reduce potential conflicts with coyotes in the region. / Ph. D.
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Factors affecting Wilson's Plover (Charadrius wilsonia) demography and habitat use at Onslow Beach, Marine Corps Base Camp Lejeune, North CarolinaRay, Kacy Lyn 22 March 2011 (has links)
The Wilson’s Plover (Charadrius wilsonia) is a species of concern in most southeastern U.S. coastal states, where it breeds and winters. The U.S. Shorebird Conservation Plan listed this species as a Species of High Concern (Prioritization Category 4), and the U.S. Fish and Wildlife Service has designated it as a Bird of Conservation Concern (BCC). Despite its conservation status, Wilson’s Plover population trends are poorly understood and little research has been conducted examining habitat factors affecting this species’ breeding and foraging ecology. I collected Wilson’s Plover demographic data and explored which habitat characteristics influenced breeding success and foraging site selection among three coastal habitat types (i.e. fiddler crab (Uca spp.) mud flats, beach front, and interdune sand flats) at Onslow Beach, Marine Corps Base Camp Lejeune, North Carolina, 2008-2009. I observed little difference between years in nest success (≥ 1 egg hatched), failure, and overall nest survival. The majority of nest failures were caused by mammalian predators. For those nests that hatched successfully, greater proportions were located in clumped vegetation than on bare ground or sparsely vegetated areas. In-season chick survival for both years was higher for nests that hatched earlier in the season, and for nests farthest from the broods’ final foraging territory. Productivity estimates (chicks fledged per breeding pair) were not significantly different between years (0.88 ± 0.26 fledged/pair in 2008, 1.00 ± 0.25 fledged/pair in 2009) despite a shift in foraging behavior, possibly related to habitat alterations and availability in 2009. My findings indicate that Wilson’s Plover adults and broods were flexible in establishing final foraging territories; in 2008 all final brood foraging territories were on fiddler flats while in 2009, final foraging territories were sometimes split between fiddler flats, beach front, and interdune sand flats. For those Wilson’s Plovers establishing territories on fiddler flats, area of the flat was the most important feature explaining use versus non-use of a particular flat; area ≥ 1250 m² was preferred. Close proximity to water and vegetative cover were also important habitat features in foraging site selection on fiddler crab mud flats, and in all habitat types combined. My findings will directly contribute to population and habitat research goals outlined in the U.S. Shorebird Plan and will supplement limited data about foraging and habitat use related to Wilson’s Plover breeding ecology. / Master of Science
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Foraging and menstruation in the Hadza of TanzaniaFitzpatrick, Katherine January 2018 (has links)
The Hadza, residing near Lake Eyasi in northern Tanzania, represent one of the last remaining hunter-gatherer populations. Inhabiting the same area as our hominin ancestors and exploiting very similar resources, the Hadza maintain a foraging lifestyle characterised by a sexual division of labour. Studies of their foraging and food sharing habits serve as the foundation to numerous hypotheses of human behaviour and evolution. Data from the Hadza have featured heavily in debates on the sexual division of labour. These debates focus predominantly on men’s foraging, including how and why men provision. Women’s provisioning, on the other hand, is seldom explicitly examined and is often presumed to be constrained by reproduction. This thesis contributes to debates on the sexual division of labour by investigating how a woman’s reproductive status affects her foraging behaviours. Observational data on women’s foraging are investigated from 263 person/day follows (1,307 hours total) across 10 camps between 2004 and 2006. These data present the first quantitative documentation of forager women’s eating and sharing outside of camp. Interview data on women’s reproductive timeline are also analysed from in-depth interviews with 58 women from 9 camps in 2015. Spanning from menarche to menopause, these data offer the first quantitative and qualitative documentation of forager women’s menstruation. The results demonstrate that Hadza women eat and share over 800 kilocalories outside of camp per person/day. They regularly give and receive food, including gifts of honey from men. Breastfeeding women are more likely to give gifts and give more gifts than non-breastfeeding women. When they bring nurslings with them outside of camp, they forage less kilocalories per hour. Post-menopausal women eat less relative to what they forage, are less likely to receive gifts, rest less and forage more than pre-menopausal women. Although Hadza women describe their foraging workload as most difficult during late pregnancy, no significant differences in eating, sharing, resting or foraging are observed for pregnant women. Menstrual data from the Hadza reveal that menstruation is not only culturally relevant to the sexual division of labour, but it is also biologically relevant to current understandings of fertility. The majority (60%) of Hadza women report not doing their normal work during menstruation. They also report menstruation-related taboos for berry picking. The thesis presents an in-depth review of women’s menstruation, from the duration of menses to the menstrual cleaning process.
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Dynamique spatio-temporelle des ressources et écologie de l'abeille domestique en paysage agricole intensif / Spatio-temporal dynamic of resources and honey-bee ecology in intensive agricultural landscapesRequier, Fabrice 18 December 2013 (has links)
L'effondrement des populations d'abeilles domestiques, observé à l'échelle mondiale depuis une vingtaine d'années, est particulièrement alarmant, provoquant le déclin de la filière apicole mais également celui d'un pollinisateur essentiel en milieu agricole. La conservation de l'abeille domestique et de l'apiculture en paysage agricole est donc actuellement un enjeu majeur pour de nombreux acteurs. L'intensification de l'agriculture, insufflée par la politique agricole européenne, est désignée comme une cause majeure dans le déclin de la biodiversité, dont les abeilles sauvages. De nombreuses études ont révélé que le manque de ressources florales est une cause majeure de ce déclin généralisé, mais de façon surprenante, cette cause n'est que très peu investiguée à l'heure actuelle pour l'abeille domestique. Plus généralement, l'écologie de l'abeille domestique en paysage agricole est mal connue. A l'interface entre écologie comportementale, évolutive et paysagère, l'objectif général de cette thèse est d'étudier l'influence conjuguée de l'intensification de l'agriculture et de la dynamique spatio-temporelle des ressources florales en paysage agricole sur (i) leur utilisation et (ii) l'histoire de vie des abeilles. L'originalité de cette étude provient de l'envergure spatiale et temporelle des données empiriques collectées à l'aide de vastes dispositifs de suivis tant au niveau individuel qu'au niveau des colonies. Les résultats obtenus confirment l'influence négative de l'intensification de l'agriculture sur l'écologie de l'abeille domestique. En effet, la dynamique des ressources dominées par trois cultures majeures que sont le colza, le tournesol et le maïs, provoque l'apparition d'une déplétion d'approvisionnement en pollen et nectar. Des ressources aujourd'hui marginalement présentes en paysage agricole intensif telles que les zones boisées et les adventices jouent un rôle prépondérant dans le régime alimentaire des abeilles, pouvant contrer l'intensité de cette déplétion d'approvisionnement. Par des mécanismes a priori adaptatifs, les colonies et les individus adaptent leurs comportements et histoire de vie en réponse à la déplétion d'approvisionnement. Cependant, ces mécanismes de compromis d'allocation des ressources ont un coût important et aboutissent à un affaiblissement des colonies, qui se traduit par la mortalité hivernale des colonies d'abeilles domestiques. Cette étude révèle empiriquement l'importance de la dynamique des ressources dans les causes du déclin de l'abeille domestique, et évoque la présence d'une disette alimentaire en céréaliculture intensive. Ces résultats sont discutés dans l'optique de concevoir des mesures de conservation de l'abeille domestique, de l'apiculture et du service de pollinisation en paysage agricole intensif, afin de limiter les stress environnementaux pour les abeilles tels que le manque de ressources florales et l'exposition aux pesticides. / The collapse of honey bee populations, described around the world for twenty years, is particularly alarming because it causes the decline of beekeeping and of an essential pollinator in agricultural habitats. The conservation of honey bees and beekeeping in agricultural landscape is currently a major challenge for many operators. The agricultural intensification, instilled by the (European) Common Agricultural Policy, is considered as a major cause in the decline of biodiversity, including wild bees. Many studies have shown that lack of floral resources is a major cause of this widespread, but surprisingly, this cause of decline is very few investigated actually to honey bees. More generally, the honey bee ecology in agricultural landscapes is poorly understood. At the interface between behavioral, evolutionary and landscape ecology, the overall objective of this PhD thesis was to study the combined influences of agricultural intensification and the spatio-temporal dynamics of floral resources on (i) the use of this resource and (ii) the life history of honey bees. The originality of this study comes from its large spatial and temporal scale as well as its joint approach at individual and colony levels. The results confirm a negative impact of agricultural intensification on the honey bee. Indeed, three major crops i.e. rapeseed, sunflower and maize have created a temporal resource dynamic which causes a strong food supply depletion in pollen and nectar. Some resources more marginally represented in intensive agricultural landscapes such as wood and weeds play an important role in the honey bee diet, being able to restrict the intensity of food supply depletion. By adaptive mechanisms, colonies and individuals adapt their behavior and life history in response to the food supply depletion. However, these trade-off mechanisms in resource allocation have a significant cost and generate a weakening of colonies that increases overwintering mortality of honey bee colonies. This study shows empirically the importance of the resource dynamic in the causes of honey bee decline, and highlights the presence of a food-shortage period in cereal farming systems. These results are discussed so as to build conservation measures on the honey bee, beekeeping and pollination service in intensive agricultural landscapes, in order to limit environmental stress for honey bees such as lack of floral resources and pesticide exposure.
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Spatial and temporal patterns in resource dispersion and the structure of range use and co-existence in a social omnivore Chlorocebus AethiopsBarrett, Alan Sean 11 1900 (has links)
The movements of two vervet monkey troops were studied to determine whether they optimize their rate of food intake in relation to seasonal energy availability. The effect of variation in habitat structure on the troops’ foraging strategies while utilizing temporally and spatially distributed resources was determined. Troop home range boundaries were delineated, the various plant communities and species utilised by the troops identified and classified, and variations in home range and vegetation structure were reported. The diets of the troops were determined and compared. Effects of coexistence on competition were assessed. Vervet food trees were randomly selected, marked and seasonal phenological data collected. Samples of food items constituting the two troops diets were collected for energy analysis. Using geostatistical interpolation techniques, monthly energy values were extrapolated onto home range grids for the two vervet monkey troops. Grids were stored as database files that were interrogated through GIS simulation models. Using the stochastic processes inherent in Markov chain theory, a series of non-returning random walks were simulated for comparison to original routes taken by the two troops. Results from comparisons of home range energy, day range lengths and areas, shortest route energy to actual route energy, time spent in high energy areas, and energy utilisation from actual and randomly generated routes indicated that the two troops optimize resource energy available to them by adopting flexible foraging strategies. In environments where temporal and spatial variations in habitat structure affect the distribution of resources, it is essential that animals develop optimal foraging strategies to survive. For the two troops investigated, foraging strategies fluctuate between being time minimizers in more heterogeneous environments where resources are abundant, and energy maximisers in homogeneous environments where resources are constrained by low diversity and seasonality. / Environmental Sciences (Department) / D.Litt et Phil (Environmental Management)
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