Orientador: Emygdio Leite de Araujo Monteiro-Filho / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-07T08:06:38Z (GMT). No. of bitstreams: 1 Nakano-Oliveira_Eduardo_D.pdf: 2929828 bytes, checksum: ec08e52b7a82274d549faf563c6bd37f (MD5) Previous issue date: 2006 / Resumo: Na Floresta Atlântica, existe uma grande deficiência de informações sobre os mamíferos da ordem Carnívora, principalmente em ambientes estuarinos e insulares, assim esse estudo teve o objetivo geral de fornecer as primeiras informações sobre a comunidade de mamíferos carnívoros em três ilhas da região do Complexo Estuarino Lagunar Iguape/Cananéia, litoral sul de São Paulo e tentar identificar as principais ameaças ambientais locais utilizando essas espécies como indicadores ecológicos. Para isso, foi utilizada uma combinação de métodos acreditando que essa seria a forma mais eficiente de reunir dados variados. A riqueza foi estimada através de identificação de pegadas e fezes, além de avistamentos, capturas e armadilhas fotográficas. A dieta foi estudada através da análise de conteúdo fecal. A impressão dos moradores locais em relação aos carnívoros da região foi possível através da aplicação de questionários fechados. A influência do contato antrópico sobre carnívoros onívoros foi analisada através do monitoramento de sete cachorros-do-mato por rádio telemetria, sendo que três pertenciam a um grupo que freqüentava constantemente áreas habitadas e quatro indivíduos pertenciam a um grupo sem contato com humanos. Além desses métodos, durante todo o trabalho foram registrados todos os tipos de distúrbios ambientais encontrados. A Ilha do Cardoso foi a que apresentou maior riqueza de carnívoros silvestres (n=9), seguido pela Ilha Comprida (n=6) e Ilha de Cananéia (n=5). Em relação à dieta, as lontras c onsumiram peixes e caranguejos, os mão-peladas se alimentaram principalmente de crustáceos e frutos e os cachorros-do mato apresentaram uma dieta bastante variada, incluindo caranguejos, insetos, frutos e pequenos vertebrados. Os felídeos consumiram vertebrados sendo que os de maior porte foram predados apenas por onça-parda. De maneira geral, os moradores entrevistados tem afinidade com a natureza, mas ainda demonstram um certo receio em relação aos carnívoros silvestres, principalmente devido a problemas de predação sobre animais de criação como galinhas e patos, e sobre peixes em ¿viveiros¿ naturais. Os cachorros-do-mato monitorados indicaram alguns problemas devido ao contato antrópico. O grupo selvagem ocupava áreas bem maiores, forrageava por mais tempo e consumia apenas presas e frutos nativos. Os indivíduos do grupo antrópico visitavam constantemente áreas com lixo orgânico, ocupavam áreas bastante reduzidas e apresentavam menos atividade. De maneira geral os problemas ambientais detectados estavam direta ou indiretamente relacionado à espécie humana. Entre eles foram destacados a presença de animais domésticos e lixo em áreas naturais, o conflito entre animais silvestres e donos de criações, destruição de margens de rios, entre outros. A última parte da tese expõe os problemas, recomenda algumas soluções possíveis e cita os projetos desenvolvidos ou em desenvolvimento que estão tentando resolver esses problemas ou levantar informações mais específicas para esse fim / Abstract: Considering that in the Atlantic Forest, there is a lack of information on the mammals of the Carnivora order, mainly in the estuaries and islands, this study had the general objectives of providing primary information on the community of carnivore mammals of three islands in the area of Iguape/Cananéia region, south coast of São Paulo and trying to identify the main local environmental threats using these species as ecological indicators. For that, a combination of methods was used because it was believed that this would be the most efficient way of gathering varied data. The richness was estimated using the identification of footprints and feces and also direct observation, captures and photographic traps. The diet was studied through the analysis of the fecal content and a preliminary analysis of the local residents' impression regarding the carnivores of the area was possible due to the use of questionnaires. The influence of the antropic contact on carnivorous omnivores was analyzed by monitoring seven crab-eating- foxes by radio telemetry. Three of them belonged to a group that was constantly in inhabited areas and four individuals belonged to a group without any humans contact. Besides these methods, during the whole study all types of environmental disturbances found were registered. The Cardoso Island presented the greatest richness of wild carnivorous (n=9) followed by the Comprida Island (n=6) and the Cananéia Island (n=5). About the diet, the otters consumed fish and crabs, the crab-eating-raccoons fed mainly on crustaceans and fruits and the crabeating-foxes had a quite varied diet, including crabs, insects, fruits and small vertebrates. The felids consumed vertebrates and the largest ones were predated only by the puma. In general, the residents interviewed have some affinity with nature, but they still demonstrate a certain fear of the wild carnivores, mainly due to predation problems with animal breeds such as chickens, ducks, and fish. The crab-eating- foxes monitored indicated some problems due to the antropic contact. The wild group was in much larger areas, foraged for more time and consumed just prays and native fruits. The individuals of the antropic group were constantly in areas with organic garbage; they occupied quite reduced areas and were less active. In general, the environmental problems detected were direct or indirectly related to the human species. Among other problems, the presence of domestic animals and garbage in natural areas, the conflict between wild animals and breeders and the destruction of river banks were emphasized. The last part of the thesis presents the problems, recommends some possible solutions and mentions the projects developed or being developed that are trying / Doutorado / Doutor em Ecologia

With the ever-increasing human population, more people reside in urban areas than ever before; this is having marked effects on the landscape and in turn, wildlife. This study uses automatically triggered wildlife cameras to assess the distribution of three carnivore species (coyotes, Canis latrans; red foxes, Vulpes vulpes; and gray foxes, Urocyon cinereoargenteus) around the Pioneer Valley of Massachusetts in relation to a gradient of human development. Cameras were placed at 141 locations within the 320-km2 study area over the course of three field seasons (3,052 trap nights). Relative abundances for fourteen other species and site characteristics (e.g., elevation, forest cover type, distance to urban edge) for each camera location were determined to develop a generalized linear model for the distribution of each species across the study area. Coyote distribution was most affected by the relative abundances of their prey species and not by landscape characteristics or sympatric carnivore species. Coyotes are the top predator in the area and therefore their distribution is correlated with the relative abundances of their prey species, unlike other parts of their range where they are controlled by larger carnivores. Red and gray foxes both had negative relationships with the relative abundance of coyotes as coyotes have been shown to adversely impact fox distributions and access to resources. Both red and gray foxes were also negatively or uncorrelated with increased levels of urbanization, which is both supported and refuted by published literature and is likely system specific.

No description available.

MSc (Zoology) / Department of Zoology / The adverse ecological effects of landscape modification by humans are well known and continue to be studied. Habitat disturbances arising from such modifications result in various levels of biodiversity loss. Amongst mammals, large carnivores are usually the first to disappear, leaving a gap in the trophic pyramid. However, ecologically adaptive small carnivores, free from the effects of intraguild predation can readily fill this gap (i.e. mesopredator release). In highly productive disturbed habitats, small mammals may thrive, reaching densities that can support an abundant and diverse suite of small carnivores. After frequent sightings of serval (Leptailurus serval) on the highly disturbed Sasol Synfuels Operations property, three camera trap surveys were conducted between 2014 and 2015 to study its ecology. The resulting data was subsequently used to study the site’s small carnivores. Multispecies occupancy modelling was used to determine detection (p) and occupancy (ψ) probabilities and estimate species richness across the study area. Site-specific covariates were then modelled against abundance values to identify any correlations. Out of 23 small carnivore species predicted to occur on the site, 11 were detected. Spatially, estimated species richness was highest in disturbed habitats, while it was slightly lower in Grassland possibly due to undersampling. Detection and occupancy probabilities were low (except for serval), with interspecies variations. It is suspected that this is the result of survey bias towards serval. The only covariate showing any significant effect was livestock presence, negatively affecting serval occupancy. Estimated species richness was used as a proxy to identify high- or low-predation areas. Within these areas, three vegetation treatments were selected (low, medium and high cover). Small mammal foraging behaviour under varying predation pressures within these treatments was then studied using the giving-up density (GUD) framework. Differences in GUDs were examined using generalised linear mixed models (GLMM). Small mammal trapping in the study area showed that four-striped grass mouse (Rhabdomys sp.; diurnal) and multimammate mouse (Mastomys sp.; nocturnal) were dominant. Nocturnal GUDs were lower than diurnal, which is interesting as four-striped grass mice are more abundant than multimammate mice. This indicates that density alone does not influence GUDs. Additionally, no significant difference in GUDs was observed between predation and vegetation treatments. I suggest that observed GUDs are linked to individual or combined impacts of interspecific differences in foraging behaviour, metabolic requirements or temporal variations in perceived predation pressure. GUDs also varied between surveys, being lower in mid- compared to early winter. This might be attributable to decreased availability of food and greater metabolic requirements in mid-winter. The results show that modified landscapes (such as the study site) can contribute to biodiversity conservation, especially of small carnivores, the adaptability of which allows them to flourish in disturbed habitats. Under favourable conditions, ecologically flexible small mammal species seem to be unaffected by the risks associated with an abundance of small carnivores. While the processes governing the dynamics of predator and prey communities in disturbed systems are not entirely clear, the conservation potential of such areas cannot be ignored and deserves more attention from researchers. / NRF

No description available.

Ecological communities are most commonly structured by a mixture of bottom-up processes such as habitat or prey, competition within the same trophic level, and top-down forces from higher trophic levels. Carnivore guilds play a vital role in the broader ecological community by stabilizing or destabilizing food webs. Consequently, factors influencing the structure of carnivore guilds can be critical to patterns in ecosystems. Coyotes (Canis latrans), bobcats (Lynx rufus), gray foxes (Urocyon cinereoargenteus), raccoons (Procyon lotor), red foxes (Vulpes vulpes), and striped skunks (Mephitis mephitis) occur sympatrically throughout much of their geographic ranges in North America and overlap in resource use, indicating potential for interspecific interactions. Although much is known about space use, habitat relationships, and activity patterns of the individual species separately, little is known about factors that facilitate coexistence and how interactions within this guild influence distribution, activity, and survival of the smaller carnivores. For example, gray fox populations appear to have declined in Illinois since the early 1990s and it is unknown if the increase in bobcat and coyote populations during the same time period is the cause. I conducted a large-scale non-invasive carnivore survey using an occupancy modeling framework to quantify factors affecting the structure of this widely-occurring carnivore guild. I used baited remote cameras during 3-week surveys to detect carnivores at 1,118 camera-points in 357 2.6-km2 sections (clusters of 3-4 cameras/section) in the 16 southernmost counties of Illinois (16,058 km2) during January-April, 2008-2010. I collected microhabitat data at each camera-point and landscape-level habitat data for each camera-cluster. In a multi-stage approach, I used information-theoretic methods to develop and evaluate models for detection, species-specific habitat occupancy, multi-species co-occupancy, and multi-season (colonization and extinction) occupancy dynamics. I developed hypotheses for each species regarding the occupancy of areas based on anthropogenic features, prey availability, landscape complexity, and vegetative landcover. I used photographic data, Poisson regression, and mixed-model logistic regression to quantify temporal activity of carnivores in the study area and how interspecific factors influence temporal patterns of activity. Of the 102,711 photographs of endothermic animals I recorded photographs of bobcats (n = 412 photographs), coyotes (n = 1,397), gray foxes (n = 546), raccoons (n = 40,029), red foxes (n = 149) and striped skunks (n = 2,467). Bobcats were active primarily during crepuscular periods, and their activity was reduced with precipitation and higher temperatures. The probability of detecting bobcats at a camera point decreased after a bobcat photograph was recorded, suggesting avoidance of remote cameras. Across southern Illinois, bobcat occupancy at the camera-point and camera-cluster scale (point = 0.24 ± 0.04, cluster = 0.75 ± 0.06) was negatively influenced by anthropogenic features and infrastructure. Bobcats had high rates of colonization (0.86) and low rates of extinction (0.07) during the study, suggesting an expanding population, but agricultural land was less likely to be colonized. The number of coyote photographs decreased with increased temperature, but increased with previous coyote photographs, suggesting an attraction to bait in cold weather. Nearly all camera clusters were occupied by coyotes (cluster = 0.95 ± 0.03) during the entire study. At the camera-point scale, coyote occupancy (overall point = 0.58 ± 0.03) was higher in hardwood forest stands with open understories than in other habitats. Similar to coyotes, gray foxes were more likely to be photographed in cold weather and after a previous detection had occurred. However, gray fox occupancy was much lower (point = 0.13 ± 0.01, cluster = 0.29 ± 0.03) at all scales. At the camera-cluster scale, with a buffer-area size that represented 20% of the estimated home-range size of gray foxes, the species selected spatially-complex areas with high proportions of forest, and low proportions of grassland and agriculture land cover. Gray fox occupancy of camera clusters was positively related to anthropogenic features within 100% estimated home-range buffers. Collectively, the results suggest gray fox occupancy was greatest near, but not in, anthropogenic developments. Red foxes occupied a similar proportion of the study area as gray foxes (point = 0.12 ± 0.02, cluster = 0.26 ± 0.04), but were more closely associated with anthropogenic features. Indeed, at all three scales of red fox occupancy analysis, anthropogenic feature models received more support than other hypotheses. Camera-cluster extinction probabilities were higher for both gray foxes (0.57) and red foxes (0.35) than their colonization rates (gray fox = 0.16, red fox = 0.06), suggesting both species may be declining in southern Illinois. I recorded more striped skunk photographs in January and February (i.e., during the breeding period) than in March and April. Striped skunks occupied a large portion of the study area (point = 0.47 ± 0.01, cluster = 0.79 ± 0.03) and were associated primarily with anthropogenic features, especially if the features were surrounded by agricultural land and not forest. Raccoons were essentially ubiquitous within the study area, being photographed in 99% of camera clusters. In some instances, the presence of other carnivores appeared to be an important factor in the occupancy of the 4 smaller species, but in general, habitat models were more supported than co-occurrence models. Habitat had a stronger influence on the occupancy of gray foxes and red foxes than did the presence of bobcats. However, the level of red fox activity, represented by the number of photographs recorded in a camera cluster, was negatively correlated with bobcat activity. Gray fox occupancy and level of activity were reduced in camera-clusters occupied by coyotes, but were not related to bobcat occupancy. When not considering the presence of coyotes, gray foxes appeared to use camera points with fewer hardwood and more conifer trees, which was counter to previous findings. However, when adding the effect of coyote presence, gray fox point models indicated a positive relationship with hardwood stands. Therefore, gray foxes were more likely to occupy camera points in hardwood stands than conifer stands if coyotes were also present; suggesting that hardwood stands may enhance gray fox-coyote coexistence. The 2 fox species appeared to co-occur with each other at the camera-point scale more frequently than expected on the basis of their individual selection of habitat. Similarly, camera-point occupancy of red foxes was higher when coyotes were present. These apparent canid associations may be a response to locally-high prey abundance or an unmeasured habitat variable. Activity levels of raccoons, bobcats, and coyotes were all positively correlated. Collectively, my results suggest that although gray foxes and red foxes currently coexist with bobcats and coyotes, the foxes have reduced activity in the areas occupied by larger carnivores, especially when bobcats and coyotes are highly active. Further, hardwood stands may contain trees with structure that enhances tree-climbing by gray foxes, a behavior that probably facilitates coexistence with coyotes. Therefore, efforts to manage gray foxes should focus on maintaining and increasing the amount of mature oak-hickory forest, which presumably provides a suitable prey base and refugia from intraguild predation. Additionally, the varying results from different scales of analyses underscore the importance of considering multiple spatial scales in carnivore community studies.

Understanding species’ distribution, density, and sources of bias in population estimates is critical for reliable conservation strategies. I assessed American black bear distribution, density, and abundance in southern Missouri. Using anecdotal occurrence data, I demonstrated support for a northward trend in extent of occurrences over time and a positive correlation between bear distribution and human–bear incidents. I also used GPS telemetry and camera traps to investigate detection biases in DNA hair snare methods and tested efficacy of two sampling designs for estimating density using spatial capture-recapture models. Results demonstrated that detection probability decreased following a negative asymptotic relationship with decreasing bear proximity to snares and that hair deposition rates decreased over time. Precision of estimates for low density populations with non-uniform distribution increased when using multiple arrays with intensive snare spacing. Optimizing the tradeoff among snare spacing, coverage, and sample size is important for estimating parameters with high precision.

Movement of organisms is a fundamental component of many ecological processes, and should be subject to strong selective pressures. Spatial selection is the process by which individuals choose the locations to acquire necessary resources or avoid risk, and the relative importance of different factors on spatial selection may change depending on the scale being analyzed. Under the framework of optimality, an individual should attempt to structure their spatial selection economically to maximize fitness. I studied black bear (Ursus americanus) space use, habitat selection, and movement under the optimality paradigm in three populations (Michigan, Missouri, and Mississippi) at four different scales: regional, annual home range, seasonal home range, and denning sites. At the regional scale, I found that black bears displayed scale-dependent land cover selection for movement, selecting forested areas at coarser scales and avoiding anthropogenic disturbance at finer scales, and that large contiguous forests and riparian corridors most facilitate connectivity among protected areas. At the annual and seasonal home range scales, I found black bears display scale-dependent optimizing strategies. Individuals locating their annual ranges to maximize access to areas of high vegetation productivity, together with the high productivity of ranges of all sizes, suggests an energy maximizing strategy, while the negative relationship between range size and both fragmentation and forest proportion suggests area minimizing. More limiting factors act at larger scales, which suggests productivity is the strongest limiting factor and energy maximizing is the dominant strategy while plasticity allows for seasonal area minimizing. At the den site scale, I found that both female and male black bears appeared to minimize anthropogenic risk during denning; however female black bears have a flexible response to anthropogenic disturbance, attempting to minimize it when alone or with older offspring, yet having increased tolerance when infanticide is greater after cubs are born and following den emergence. By quantifying black bear space use and selection across multiple scales, diverse areas, over time, and among and within individuals, I revealed consistent scale-dependent responses to environmental and biological factors while highlighting the intrinsic plasticity of this flexible omnivore.

During 2000-2004 I studied the population status of the Formosan clouded leopard (Neofelis nebulosa brachyurus) and the ecology of its prey and other sympatric carnivores in the largest remaining lowland primary forest in southern Taiwan. My research team and I set up 232 hair snare stations and 377 camera trap sites at altitudes of 150-3,092m in the study area. No clouded leopards were photographed in total 13,354 camera trap days. Hair snares did not trap clouded leopard hairs, either. Assessment of the prey base and available habitat indicated that prey depletion and habitat loss, plus historical pelt trade, were likely the major causes of extinction of clouded leopards in Taiwan. Using zero-inflated count models to analyze distribution and occurrence patterns of Formosan macaques (Macaca cyclopis) and 4 ungulates, we found habitat segregation among these 5 herbivore species. Formosan macaques, Reeve's muntjacs (Muntiacus reevesi micrurus), and Formosan serows (Nemorhaedus swinhoei) likely were the most important prey species of Formosan clouded leopards given their body size and high occurrence rates in lower altitudes. In contrast, sambar deer (Cervus unicolor swinhoii) tended to occur more frequently as altitude increased. Formosan macaques exhibited seasonal differences in occurrence rates and were absent at altitudes > 2,500m in winter. Only Formosan serows showed preference for cliffs and rugged terrain, while the other 4 species, except wild boars (Sus scrofa taivanus), avoided these areas. Habitat segregation in forest understory and structure were more pronounced among the 4 ungulates. Forest structure rarely affected occurrence rates of Formosan macaques on the ground. Niche relationships of the other sympatric carnivores were studied through habitat, diet, and temporal dimensions. Resource partitioning by carnivores was observed. Altitude was the strongest factor explaining the composition of the carnivore community in the local study-area scale and in the landscape scale across Taiwan. Carnivores could be divided into 2 groups: low-mid altitude consisting of Formosan ferret badgers (Melogale moschata subaurantiaca), gem-faced palm civets (Paguma larvata taivana), lesser oriental civets (Viverricula indica taivana), crab-eating mongooses (Herpestes urva formosanus), leopard cats (Prionailurus bengalensis chinensis), and feral cats (Felis catus), and the mid-high altitude group consisting of yellow-throated martens (Martes flavigula chrysospila), Siberian weasels (Mustela sibirica taivana), and Asiatic black bears (Ursus thibetanus formosanus). Carnivore richness was higher at mid altitudes where these 2 groups overlapped (i.e. mid-domain effect). The low-mid altitude carnivores were more nocturnal and tolerant of human activity and forest alteration except crab-eating mongooses, which were diurnal and avoided human encroachment. Similar to crab-eating mongooses, the mid-high altitude carnivores also avoided human encroachment and were diurnal except for Siberian weasels, which were more nocturnal. Diet summary based on their major food items for all sympatric carnivores revealed 3 groups of foragers which foraged on: invertebrates, small mammals, and plant fruits. Felidae, yellow-throated martens, and Siberian weasels preyed on small mammals. Asiatic black bears and gem-faced palm civets ate mostly plant fruits. The other 3 carnivores were mainly invertebrate foragers. These 9 carnivores partitioned resource uses in the 3 niche dimensions except for some overlap in resource use by leopard cats and feral cats. Prey base for Formosan clouded leopards and the carnivore richness in Taiwan were found to be lower in areas with higher levels of human activity. On the other hand, Formosan macaques and ungulates could become over-abundant without human hunting and top carnivore predation. Mesopredator release may occur because of vanishing top carnivores, causing reduction of the lower trophic level prey species. It is important to assess the cascading impacts of the loss of the Formosan clouded leopards and Eurasian otters (Lutra lutra chinensis) and the declining Asiatic black bears and to consider reintroduction of Formosan clouded leopards, as well as active management of the other larger mammals. These results provided baseline information for reintroduction of clouded leopards and management of their prey and generated new hypotheses regarding the ecology of these large mammals for future investigation. / Ph. D.

Tanzania’s Ruaha landscape is an international priority area for large carnivore conservation, harbouring roughly 10% of the world’s lions, and important populations of leopards and spotted hyaenas. However, these large carnivore populations are threatened by intense retaliatory killing due to human-carnivore conflict on village land around Ruaha National Park (RNP), mostly as a result of livestock predation by lions, leopards and spotted hyaenas. Moreover, a current lack of ecological data on the distribution of these carnivores hinders the development of effective strategies for conservation and targeted conflict mitigation in this landscape. This study aimed to identify the most significant ecogeographical variables (EGVs) influencing the distribution of lions, leopards and spotted hyaenas across the Ruaha landscape, and to map areas of conservation importance for these species. In addition, the study assessed the influence of EGVs on livestock predation risk by these carnivores in the village land around RNP, and generated a predictive map of predation risk. The relative importance of livestock husbandry practices and EGVs in terms of influencing predation risk within enclosures was also investigated. Proximity to rivers was the most important variable influencing the distribution of large carnivores in Ruaha, and contributed to predation risk of grazing livestock. The traditional livestock husbandry adopted in bomas appeared insufficient to alleviate the inherent risk of predation by large carnivores. The study produced the first detailed maps of lion, leopard and spotted hyaena distribution in the critically important Ruaha landscape, and identified likely livestock depredation hotspots. These results will target conflict mitigation approaches around Ruaha, by identifying particularly high-risk areas for livestock enclosures and grazing stock. Improving husbandry in these areas could help reduce livestock depredation and retaliatory carnivore killing, therefore reducing one of the most significant conservation threats in this critically important landscape.