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Parallels between playbacks and Pleistocene tar seeps suggest sociality in an extinct sabretooth cat, SmilodonCarbone, C, Maddox, T, Funston, PJ, Mills, MGL, Grether, GF, Van Valkenburgh, B 23 February 2009 (has links)
Inferences concerning the lives of extinct animals
are difficult to obtain from the fossil record. Here
we present a novel approach to the study of extinct
carnivores, using a comparison between fossil
records (nZ3324) found in Late Pleistocene tar
seeps at Rancho La Brea in North America and
counts (nZ4491) from playback experiments used
to estimate carnivore abundance in Africa. Playbacks
and tar seep deposits represent competitive,
potentially dangerous encounters where multiple
predators are lured by dying herbivores. Consequently,
in both records predatory mammals and
birds far outnumber herbivores. In playbacks, two
large social species, lions, Panthera leo, and
spotted hyenas, Crocuta crocuta, actively moved
towards the sounds of distressed prey and made
up 84 per cent of individuals attending. Small
social species (jackals) were next most common
and solitary species of all sizes were rare. In the La
Brea record, two species dominated, the presumably
social dire wolf Canis dirus (51%), and the
sabretooth cat Smilodon fatalis (33%). As in the
playbacks, a smaller social canid, the coyote Canis
latrans, was third most common (8%), and known
solitary species were rare (!4%). The predominance
of Smilodon and other striking similarities
between playbacks and the fossil record support
the conclusion that Smilodon was social.
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Comparing density analyses and carnivore ecology in Madagascar's southeastern rainforestGerber, Brian Daniel 15 December 2010 (has links)
Madagascar is renowned for its biodiversity, but also for forest loss, fragmentation, and degradation, making it a global conservation priority. With few studies dedicated to Madagascar's carnivores, little is known about their ecology. My objectives were to 1) compare density estimation techniques applicable to enumerating rare and/or elusive carnivores, 2) investigate Malagasy carnivore distributions, abundance and density, and occupancy/use across four sites that vary in forest disturbance, and 3) explore temporal activity patterns of rainforest carnivores. I found the spatially-explicit-capture-recapture models were empirically superior, as they are flexible and account for spatial variation in detection probability and area estimation. I found both endemic and exotic carnivore composition varied among four rainforest sites: Primary, Selectively-logged, Fragments <2.5 km and Fragments >15 km from contiguous-primary rainforest. All endemic carnivores were present in the Primary and Selectively-logged rainforest, while endemic carnivore species richness decreased and exotic carnivore species richness increased in the fragmented forests. Malagasy civet (Fossa fossana) density ± SE was significantly less in the Selectively-logged compared to the Primary rainforest (1.38 ± 0.22, 3.19 ± 0.55 civets/km2, respectively); they were absent from both fragmented forests. Fossa (Cryptoprocta ferox) density ± SE was not different between the Primary and Selectively-logged rainforests (0.12 ± 0.05, 0.09 ± 0.04 adults/km2, respectively); a single animal was detected in the Fragments <2.5 km, while none were detected in the Fragments >15 km. Malagasy carnivores had varied temporal activity overlap (5.8-88.8%). C. ferox preferred crepuscular activity, but overall exhibited a cathemeral activity pattern. / Master of Science
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Diet and Feeding Ecology of the Coyotes, Black Bears, and Bobcats in Western Virginia and Preliminary Assessment of Coyote ParasitesMontague, David Miles 22 October 2014 (has links)
Although deer abundance is high throughout most areas of Virginia, parts of western Virginia, especially on public lands, have comparatively low density deer populations. Concerns voiced by sportsmen regarding declining deer numbers in this region prompted interest in research to investigate the role of predation on deer populations. The coyote (Canis latrans) is a relative newcomer to Virginia, and relatively little is known about the role coyotes play in Virginia ecosystem dynamics, including their interactions with other sympatric predators. Research studies in other areas suggest that predation from coyotes, bobcats (Lynx rufus), and black bears (Ursus americanus) may be a significant source of deer (Odocoileus virginianus) mortality, especially for fawns, and the cumulative effects of predation from these sources may also increase the potential for additive mortality in deer populations. An important consideration when comparing feeding strategies of carnivores is the relative availability of food items across the landscape. I estimated the relative seasonal availability of several potential food items in a mosaic landscape that included some areas of prescribed burning and variable timber harvest in the mountains of western Virginia between June 2011 and May 2013. I focused on 4 broad categories of food items: white-tailed deer, mid-sized mammals (raccoons, Procyon lotor, opossums, Didelphis virginiana, cottontails, Sylvilagus spp., and squirrels, Sciurus spp.), small mammals, and soft mast. I used distance sampling to estimate deer density, camera trapping techniques to estimate mid-sized mammal trapping rates and occupancy, mark-recapture techniques to estimate small mammal abundance, and vegetation sampling to estimate % cover, which I used as measures of food availability for predation. To estimate carnivore diet, I analyzed scats of coyotes (n = 334), bobcats (n = 258), and black bears (n = 107) collected monthly from June 2011 and May 2013. Additionally, I compared estimates of % occurrence to estimates of seasonal availability of deer, mid-sized mammals, small mammals, and soft mast by ranking availability of food items from 0 (unavailable) to 4 (highly available) from my monthly and seasonal food item abundance and density estimates. I then ranked % occurrence in scat on a 0 - 4 scale and compared diet rankings to food item availability where changes in rank indicate differences from the generalist diet.
Deer densities were substantially higher in Bath County (4.75 - 16.06 deer/km²) than in Rockingham County (0.17 - 3.55 deer/km²). I estimated availability of other food items only in Bath County. For mid-sized mammals, I estimated low activity as shown by constant, but low, trapping rates (#photo events/trap nights*100) of opossums, and relatively higher, constant trapping rates of cottontails. Raccoon and squirrel trapping rates were highly variable across seasons and raccoon occupancy (proportion of sites occupied) was higher in summer and fall (0.51 - 0.59) whereas squirrel occupancy was highest in October-November (0.51 - 0.53). Cottontail and opossum occupancies were higher in burned areas (0.40 - 0.57, 0.24 - 0.46, respectively), whereas raccoon and gray squirrel occupancies were higher in unburned areas (0.23 - 0.78, 0.12 - 0.58, respectively). Using program MARK I estimated high abundance and density of Peromyscus spp. in all seasons relative to other small mammal species. Densities of meadow voles and jumping mice were high seasonally in open field habitat. Densities of eastern chipmunks, red-backed voles, and Peromyscus spp. were significantly higher in burned areas relative to unburned sites. Among soft mast species, blueberries comprised the largest % occurrence. I expect a generalist predator to consume deer at a constant rate and have lower % deer occurrence in Rockingham County where deer densities are much lower. I expect seasonally constant, but low, occurrence of opossum and relatively higher, but similarly constant, occurrence of cottontail. I expect raccoon occurrence to be relatively high in summer and fall, and lower in winter. Squirrel occurrence should peak in October and November, followed by a steady decline until June. Based on availability, Peromyscus spp. should be the most commonly occurring small mammal in the diet of a generalist predator, rivaled by meadow voles (Clethrionomys gapperi) in fall and perhaps summer. I expect chipmunks (Tamias striatus) and red-backed voles to occur at constant but low rates in predator diets. I predict that various species of soft mast may occur during their respective fruiting seasons.
Deer were the most frequently occurring food item of coyotes in all months in both counties, with % biomass consumed highest in June (Bath: 60.0 - 90.9 %; Rockingham: 55.6 - 92.3%). Deer occurrence in bobcat scat peaked in June (77.54 %). In black bear scat, deer occurrence was highest in February and March (100 %), however sample sizes in these months were extremely low (n = 2, 3 respectively). All 3 predators consumed deer more than expected in June and July. In most months, coyotes consumed deer and soft mast more often than expected (1 rank higher) and they consumed deer much higher (2-3 ranks higher) than expected in January and February. While deer was a major food item in the diets of all 3 predators, it is unclear whether this observed result was caused by predation or scavenging. It is unlikely that coyotes, bears, or bobcats are preying on adult deer with high frequency. I did not estimate the availability of deer carcasses for scavenging in this study. If deer carcasses are highly available in the study area, this may explain the high occurrence of deer in carnivore scat and the lack of seasonality in coyote samples.
Mice (Peromyscus spp.) were consumed by predators less than expected based on availability, whereas squirrels and chipmunks were consumed by bobcats more than expected. Meadow and red-backed voles were consumed more than expected by both bobcats and coyotes. Mid-sized mammals occurred with expected frequency or lower in predator scats. Coyotes had the lowest diversity and variation in diet, whereas bobcat and bear diets were more diverse including seasonal use of many species. Coyotes exhibited more selectivity (based on changes, and magnitude of changes, in rankings for food item occurrence versus availability) and appear more specialized on deer in all months than bobcats.
I analyzed 203 randomly-selected coyote fecal samples using a modified Wisconsin fecal flotation technique. I identified 13 parasite taxa, 9 of which occurred with adequate frequency to permit statistical analysis. No landscape patterns or statistically significant seasonal differences were found in prevalence of parasite taxa, and only A. caninum and Eimeria spp. were significantly higher, and Cystoisospora spp. was somewhat significantly higher, in Bath versus Rockingham Counties. By comparing my data on spatio-temporal patterns of food availability to patterns in the scats of predators, we have better understanding of predator foraging strategies and can identify opportunities for targeted management to balance predator-prey dynamics with human needs and values. More research is needed on the interactions of sympatric predators in specific areas to gain further inferences regarding population-level impacts of predation on deer in western Virginia. / Master of Science
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Occurrence of Invasive Mammals and Native Carnivores in Northern PatagoniaGantchoff, Mariela Gisele 15 August 2014 (has links)
The study of biological invasions is important to management and conservation. I assessed the occurrence of invasive mammals and native mesocarnivores in northern Patagonia. Invasive species had varying responses to anthropogenic disturbance, and were differentially influenced by environmental and anthropogenic factors. Invasive species were also a substantial part of native mesocarnivores diets and appeared to influence their temporal activity, but not occupancy. Overall, I observed high spatial and temporal overlap between native carnivores and coexistence seemed facilitated by diet. Humans had both a positive and negative influence in this community, being responsible for the introduction of invasive species and possibly further facilitating their expansion, while also limiting other invasive species and potentially benefiting native species directly and indirectly. Undoubtedly, biological invasions, anthropogenic disturbance, and native communities can present complex interactions which will require further study to provide effective tools for protected areas.
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Spatial Movements and Ecology of Mountain Lions in Southern ArizonaNicholson, Kerry Lynn January 2009 (has links)
Managing wildlife in urban areas is increasingly necessary for wildlife conservation. Large carnivores like mountain lions (Puma concolor) present a particular challenge to managers because of public safety and the polarizing emotional reactions to human-lion encounters. Intensive development and conversion of large open spaces to small properties and subdivisions has caused increased habitat loss, fragmentation and encroachment. Preserving movement corridors for access to habitat patches is important in maintaining landscape connectivity to ensure viable populations adjacent to urban areas. Because mountain lion habitat is often adjacent to urbanization in Arizona and lions traverse large landscapes, mountain lions are ideal models to examine how human alteration of habitats influences their life history characteristics and ability to adapt to a variety of environments. The objective of this study was to examine the ecology and spatial movements of mountain lions surrounding urban areas. We studied habitat selection, urban use by mountain lions, spatial movements and overlap, genetic relatedness, feline disease, and ectoparasites of mountain lions in southern Arizona.
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Mammalian carnivores as bioindicators to evaluate the exposure and bioaccumulation of organic contaminants in terrestrial ecosystemsBoyles, Esmarie 01 May 2017 (has links)
To address my first objective, I opportunistically collected road-killed bobcats (n=44) throughout Illinois during 2013-2014, and analyzed their liver tissue for the presence of PCBs, PBDEs, and various other alternative halogenated flame retardants. Concentrations of ∑PCBs ranged from 76.4 ng/g lw to 3782 ng/g lw (median 562.97 ng/g lw). Male bobcats had significantly higher concentrations of PCBs than females (p = 0.04). Concentrations of ∑PBDEs (including all detectable PBDE congeners) ranged from 8.3 to 1920 ng/g lipid weight (median: 50.3 ng/g lw). Among the alternative flame retardants screened, Dechloranes (including anti- and syn-Dechlorane Plus and Dechlorane-602, 603, and 604), tetrabromo-o-chlorotoluene (TBCT), and hexabromocyclododecane (HBCD) were also detected frequently, with median concentrations of 28.7, 5.2, and 11.8 ng/g lw, respectively. Dechlorane analogue compositions in bobcats were different from that reported in other studies, suggesting species- or analogue-dependent bioaccumulation, biomagnification, or metabolism of Dechlorane chemicals in different food webs. My findings, along with previously reported food web models, suggest Dechloranes may possess substantial bioaccumulation and biomagnification potencies in terrestrial mammalian food webs. Thus, attention should be given to these highly bioavailable flame retardants in future environmental biomonitoring and risk assessments in a post-PBDE era. To address my second objective I collected raccoons (n=32) from various sites across Illinois and Missouri during 2013-2015. Liver tissues were analyzed for the presence of PBDEs and Dechloranes. ∑PBDE concentrations ranged from 19.1 ng/g lw to 2124 ng/g lw (median = 98.0 ng/g lw) and did not differ between gender or age of raccoon. Although nonsignificant (p=0.06), adult raccoons appeared to have greater PBDE concentration loads compared to juveniles. These nonsignificant differences are likely due to large variation in contaminant concentrations, possibly reflecting differences in individual raccoon diet and behavior. This is the first study reporting bioaccumulation of halogenated flame retardants in a wild felid in North America, and also the first report of PBDE accumulation in North American raccoons. The wide detection of Dechloranes, HBCD and TBCT in bobcats suggests a broad exposure of these alternative flame retardants in terrestrial apex predators in terrestrial ecosystems. The comparatively high levels of PBDEs in raccoons also suggest that biota in terrestrial habitats are still widely exposed to and susceptible to the bioaccumulation of these flame retardants.
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Patterns of carnivore competition, time-to-kill, and predation risk on white-tailed deer fawns in a multi-predator landscapePetroelje, Tyler R. 06 August 2021 (has links)
Identifying factors influencing kill rates or predation risk is crucial to relate predator effects on prey populations. In multi-predator landscapes, some predators may also perceive predation risk which may not only influence their distributions but also their effects on prey populations across landscapes. In the Upper Peninsula of Michigan, USA white-tailed deer (Odocoileus virginianus) exist in a multi-predator landscape which includes black bears (Ursus americanus), bobcats (Lynx rufus), coyotes (Canis latrans), and gray wolves (C. lupus). The objectives of this research were to examine spatial relationships among predators and their prey by identifying: 1) competition between wolves and coyotes, 2) factors influencing kill rates of predators, and 3) predator-specific predation risk for white-tailed deer fawns. We quantified the degree of temporal, dietary, and spatial overlap of wolves and coyotes at the population level to estimate the potential for interference competition and identify the mechanisms for how these sympatric canids coexist. We observed significant overlap across resource attributes yet the mechanisms through which wolves and coyotes coexist appear to be driven largely by how coyotes exploit differences in resource availability in heterogenous landscapes. We examined how heterogeneity in landscapes, search rate, and prey availability influence the time between kills for black bears, bobcats, coyotes, and wolves. Spatial heterogeneity in prey availability appeared to be a unifying extrinsic factor mediating time-to-kill across predators, potentially a consequence of more frequent reassessments of patch quality, which can reduce kill rates. We used white-tailed deer fawn predation sites to identify predator-specific predation risk with consideration for active predator occurrence, adult female white-tailed deer occurrence, linear features which may influence prey vulnerability, and habitat characteristics including horizontal cover and deer forage availability. Predator occurrence alone was a poor metric for predation risk. We identified differing landscapes of risk among ambush and cursorial foraging strategies which were more important for defining spatial variation in predation risk than predator density. These findings suggest that in a multi-predator landscape some predators may benefit from greater landscape heterogeneity due to availability of niche space, even though resource heterogeneity reduced predator efficacy and habitat complexity reduced predation risk for prey.
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Predator-prey dynamics among large carnivores and their ungulate prey: from the Great Lakes to the Last FrontierSvoboda, Nathan James 13 August 2024 (has links) (PDF)
Identifying factors that influence spatial and temporal resource use is critical to understanding ecological relationships of sympatric species. Spatial and temporal shifts in resource availability, distribution, and vulnerability can influence animal space use, movements, foraging behavior, and prey selection. Identifying these factors is critical to understanding predator-prey dynamics. In Michigan’s Upper Peninsula, white-tailed deer (Odocoileus virginianus) exist in a multi-predator system that includes black bears (Ursus americanus), wolves (Canis lupus), coyotes (C. latrans), and bobcats (Lynx rufus). On Sitkalidak Island, Alaska, plains bison (Bison bison) were recently introduced into a single-predator island landscape that contains some of the largest brown bears (Ursus arctos middendorffi) in the world. The objectives of this research were to investigate how spatial and temporal shifts in resource availability, distribution, and vulnerability impact predator space use, movements, diel activity, and resource utilization, including how competition influences resource acquisition among sympatric carnivores. In Michigan, we investigated shifts in predator space use during three time periods based on white-tailed deer fawn availability and vulnerability including the pre-parturition (PPP, 1 May–24 May) limited mobility (LMP, 25 May–30 June) and social mobility (SMP, 1 July–31 August) periods and examined predator movements during LMP and SMP. In Alaska, we investigated resource use and diel activity patterns of Kodiak brown bears and plains bison during 2 time periods determined by temporal shifts in resource availability. Carnivore responses to fawn white-tailed deer distribution and vulnerability in Michigan varied among species but were congruent with life history strategies. Carnivores did not overall rely predominantly on fawns but shifted their space use and altered movements to maximize intake of seasonal resources. In Alaska, brown bears and bison did not exhibit high landscape attribute overlap during the early and late periods suggesting bears were not recognizing bison as a potential prey source. Although we observed some overlap in utilization of landscape attributes and diel activity between bears and bison, we suggest this overlap was a result of congruent resource requirements and overlapping spatial resource acquisition. This research provides additional insight into life history strategies among co-occurring species and dynamics of multi-species predator-prey systems.
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Conservation of Large-spotted Civet Viverra megaspila in Northern Cambodia / カンボジア北部におけるビルマジャコウネコの保全Suzuki, Ai 25 September 2017 (has links)
付記する学位プログラム名: グローバル生存学大学院連携プログラム / 京都大学 / 0048 / 新制・課程博士 / 博士(地域研究) / 甲第20732号 / 地博第223号 / 新制||地||82(附属図書館) / 京都大学大学院アジア・アフリカ地域研究研究科東南アジア地域研究専攻 / (主査)教授 岩田 明久, 准教授 山越 言, 准教授 古澤 拓郎, 教授 神﨑 護 / 学位規則第4条第1項該当 / Doctor of Area Studies / Kyoto University / DGAM
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Jaguars and people : a range-wide review of human-wildlife conflictZimmermann, Alexandra January 2014 (has links)
Conflict with livestock farmers is the most serious threat to the survival of the jaguar (Panthera onca) across its range of 19 countries of the Americas. In this thesis I examine the needs for mitigating human-jaguar conflict at a range-wide scale by: a) reviewing the state of knowledge on the topic, b) modelling the risk of conflict across the range, c) analysing a series of empirical field case studies, and d) proposing appropriate approaches for different levels of conflict. Findings from 43 published studies and 117 expert-described cases show that human-jaguar conflict occurs on large cattle ranches, mixed farms and smallholdings alike. Depletion of prey and poor livestock husbandry are reported as the key reasons for depredation, regardless of ecological, cultural or socio-economic context. Attitudes and tolerance towards jaguars are not necessarily linked to losses, so recent research has focussed on understanding the behaviours of farmers. With 65% of the remaining jaguar range outside of protected areas, effective strategies for coexistence with farmers are essential. By combining geospatial datasets with expert-based information, spatial patterns of human-jaguar conflicts were presented in a predictive model of conflict hotspots. Around 85% of the total jaguar range, 72% of the total Jaguar Conservation Units area and 90% of the Jaguar Corridor area overlap with livestock, and 15% of the jaguar range has risk of conflict. Regions in which jaguars are repeatedly persecuted may become ecological traps and decimate populations. An aggregate study of 17 case studies across seven countries exposed a very large variety of geographic, agronomic and socio-economic contexts. Both within and across case studies there are considerable differences in farmers’ experiences with livestock losses, concerns about depredation, levels of tolerance and attitudes, as well as social norms towards jaguars in each community. No situational factors could be used to predict how farmers perceive jaguars and deal with depredation. The only pattern consistent across case studies was that attitudes towards jaguars are most likely predicted by a factor of perceived loses combined with the social norms of the community. In most scenarios, correctly balanced strategies of improving husbandry combined with behaviour-influencing methods may be the best way forward. To this end, a conceptual model is proposed, which distinguishes three levels of conflict and explains the importance of addressing any underlying history of grievances or incompatibility of values as part of any human-wildlife conflict mitigation strategy.
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