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1.
Camera traps (CTs) are an increasingly popular tool for wildlife survey and monitoring. Estimating relative abundance in unmarked species is often done using detection rate as an index of relative abundance, which assumes that detection rate has a positive linear relationship with true abundance. This assumption may be violated if movement behavior varies with density, but the degree to which movement behavior is density‐dependent across taxa is unclear. The potential confounding of population‐level relative abundance indices by movement would depend on how regularly, and by what magnitude, movement rate and home‐range size vary with density. We conducted a systematic review and meta‐analysis to quantify relationships between movement rate, home‐range size, and density, across terrestrial mammalian taxa. We then simulated animal movements and CT sampling to test the effect of contrasting movement scenarios on CT detection rate indices. Overall, movement rate and home‐range size were negatively correlated with density and positively correlated with one another. The strength of the relationships varied significantly between taxa and populations. In simulations, detection rates were related to true abundance but underestimated change, particularly for slower moving species with small home ranges. In situations where animal space use changes markedly with density, we estimate that up to thirty percent of a true change in relative abundance may be missed due to the confounding effect of movement, making trend estimation more difficult. The common assumption that movement remains constant across densities is therefore violated across a wide range of mammal species. When studying unmarked species using CT detection rates, researchers and managers should explicitly consider that such indices of relative abundance reflect both density and movement. Practitioners interpreting changes in camera detection rates should be aware that observed differences may be biased low relative to true changes in abundance. Further information on animal movement, or methods that do not depend on assumptions of density‐independent movement, may be required to make robust inferences on population trends. 相似文献
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The Carpentarian Pseudantechinus (Pseudantechinus mimulus) is a poorly studied dasyurid marsupial that inhabits rocky outcrops in the Mount Isa Inlier bioregion in Queensland and the Gulf Coastal and Gulf Fall and Uplands bioregions in the Northern Territory. It is readily detected by passive infrared triggered camera traps (‘camera traps’). Camera trap data can be used to develop detection probability estimates from which activity patterns can be inferred, but no effort has previously been made to determine changes in the detectability of P. mimulus throughout the year. We undertook a 13-month baited camera trap survey across nine sampling periods at 60 locations of known historic presence or nearby suitable habitat to assess the change in detection rates and detection probabilities of P. mimulus across a year. Detection probabilities were calculated from camera trap data within a single-species, multi-season occupancy framework to determine optimal survey timing. Detection probability data were used to calculate the likelihood of false absences to determine optimal survey duration. We recorded 2493 detections of P. mimulus over 10 966 camera days. Detection probability ranged from 0.009 to 0.179 and was significantly higher from April to October than from November to March. The likelihood of false absences varied by sampling period and desired level of confidence. We find that camera trap surveys for P. mimulus are best conducted from April to October, but optimal survey duration is dependent upon the time of year and desired level of confidence that an observed absence from a given site reflects a true absence at that site. Attaining a minimum of 80% confidence of absence requires as few as 9 days of survey effort in May to 16 days of survey effort in October. 相似文献
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Few previous studies on the factors that affect Striped Hyaena (Hyaena hyaena Linnaeus, 1758) occurrence and densities were done on geographically unrelated populations using different methodologies. In Israel, hyaenas occur throughout the country's steep climatic and geographical gradients, presenting a unique opportunity to study densities and habitat use across adjacent ecosystems using a unified methodology and test previous conceptions regarding the species’ habitat selection. We collected hyaena abundance-absence data using 1440 camera traps placed at 80 sites (2012– 2016). Site location ranged from hyper-arid deserts to dense Mediterranean shrubland. We assessed the effect of climate, habitat structure, elevation, geomorphological attributes (proxy for den availability), and anthropogenic development (proximity to settlements and agriculture) on hyaena densities using N-mixture models. Hyaena densities were negatively affected by anthropogenic development, and were limited by den availability. Hyaena densities did not follow a climatic or geographic gradient. Densities were highest at hyper-arid deserts and Mediterranean coastal shrublands. Despite the former conception that hyaenas prefer semi-arid open habitats and avoid extreme deserts and dense vegetation, we show that hyaenas use and even thrive in these habitats when geomorphological conditions are suitable and resources are available. 相似文献
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Kenneth F. Kellner Natasha A. Urban Robert K. Swihart 《The Journal of wildlife management》2013,77(8):1650-1663
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Emanuele Repetto;Pietro Milanesi;Livia De Caria;Francesca Della Rocca; 《Ecology and evolution》2024,14(5):e11381
The expansion of forest cover and intensification of agriculture represent the main threats to the bush cricket Saga pedo, currently listed as Vulnerable globally by the IUCN and included in Annex IV of the European Union Habitats Directive. Gathering information on its ecology and population size is challenging due to its low abundance and localized distribution. Additionally, the elusive and cryptic behavior of this species reduces the likelihood of its detection, potentially resulting in population underestimations. Thus, in this study, we aimed to (1) estimate S. pedo population size in relation to environmental variables and prey availability and (2) predict abundance of S. pedo in our study area for future monitoring in nearby territories. We found that the population of S. pedo in our study area consists of 197 (±115) individuals with a detection probability of 21.01% (±11.09). Detection probability of S. pedo further decreases on windy days. Moreover, we found that the investigated population of S. pedo occupies suboptimal areas, as highlighted not only by the predicted abundances but also by the association between S. pedo and other subfamilies of orthoptera that are ecologically very distant from our target species and mostly linked to mesophilic biotopes. Most of the individuals we observed are concentrated in small clearings completely within wooded matrices and therefore isolated from each other. Based on our results, it is possible that forest expansion toward open meadows represents the main threat to this population, transforming the clearings and xeric meadows (to which S. pedo is linked) into small and fragmented patches that are suboptimal and insufficient to host viable populations. 相似文献
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Wildlife data gathered by different monitoring techniques are often combined to estimate animal density. However, methods to check whether different types of data provide consistent information (i.e., can information from one data type be used to predict responses in the other?) before combining them are lacking. We used generalized linear models and generalized linear mixed-effects models to relate camera trap probabilities for marked animals to independent space use from telemetry relocations using 2 years of data for fishers (Pekania pennanti) as a case study. We evaluated (1) camera trap efficacy by estimating how camera detection probabilities are related to nearby telemetry relocations and (2) whether home range utilization density estimated from telemetry data adequately predicts camera detection probabilities, which would indicate consistency of the two data types. The number of telemetry relocations within 250 and 500 m from camera traps predicted detection probability well. For the same number of relocations, females were more likely to be detected during the first year. During the second year, all fishers were more likely to be detected during the fall/winter season. Models predicting camera detection probability and photo counts solely from telemetry utilization density had the best or nearly best Akaike Information Criterion (AIC), suggesting that telemetry and camera traps provide consistent information on space use. Given the same utilization density, males were more likely to be photo-captured due to larger home ranges and higher movement rates. Although methods that combine data types (spatially explicit capture–recapture) make simple assumptions about home range shapes, it is reasonable to conclude that in our case, camera trap data do reflect space use in a manner consistent with telemetry data. However, differences between the 2 years of data suggest that camera efficacy is not fully consistent across ecological conditions and make the case for integrating other sources of space-use data. 相似文献
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Hannah L. Clipp;Sarah M. Pesi;Madison L. Miller;Laura C. Gigliotti;Brett P. Skelly;Christopher T. Rota; 《Ecology and evolution》2024,14(3):e11149
Predator species can indirectly affect prey species through the cost of anti-predator behavior responses, which may involve shifts in occupancy, space use, or movement. Quantifying the various strategies implemented by prey species to avoid adverse interactions with predators can lead to a better understanding of potential population-level repercussions. Therefore, the purpose of this study was to examine predator–prey interactions by quantifying the effect of predator species presence on detection rates of prey species, using coyotes (Canis latrans) and white-tailed deer (Odocoileus virginianus) in Central Appalachian forests of the eastern United States as a model predator–prey system. To test two competing hypotheses related to interspecific interactions, we modeled species detections from 319 camera traps with a two-species occupancy model that incorporated a continuous-time detection process. We found that white-tailed deer occupancy was independent of coyote occupancy, but white-tailed deer were more frequently detectable and had greater detection intensity at sites where coyotes were present, regardless of vegetation-related covariates. In addition, white-tailed deer detection rates at sites with coyotes were highest when presumed forage availability was relatively low. These findings suggest that white-tailed deer may be exhibiting an active avoidance behavioral response to predators by increasing movement rates when coyotes are present in an area, perhaps due to reactive evasive maneuvers and/or proactive attempts to reduce adverse encounters with them. Concurrently, coyotes could be occupying sites with higher white-tailed deer densities. Because white-tailed deer did not exhibit significant shifts in daily activity patterns based on coyote occupancy, we further suggest that white-tailed deer in our study system generally do not use temporal partitioning as their primary strategy for avoiding encounters with coyotes. Overall, our study implements a recently developed analytical approach for modeling multi-species occupancy from camera traps and provides novel ecological insight into the complex relationships between predator and prey species. 相似文献
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Herve Jactel Luis Bonifacio Inge van Halder Fabrice Vtillard Christelle Robinet Guillaume David 《Agricultural and Forest Entomology》2019,21(1):8-14
- Pheromone traps are widely used for monitoring or managing insect pest populations. However, it is important to know their range of attraction to optimize the setting of pheromone trap networks.
- We propose an easy method based on the use of pairs of adjacent traps located at decreasing distance from each other. The range of attraction is deduced from the observation of reduced trap capture when the attraction range of two adjacent traps starts overlapping. The relationship between the relative trap capture and the distance between paired traps is fitted with a logistic curve.
- To empirically test these predictions, we conducted trapping experiments with the beetle Monochamus galloprovincialis, the insect vector of the pine wood nematode. Fifteen pairs of traps separated by 25 to 300 m, in France, and 18 pairs of traps distant from 25 to 400 m, in Portugal, were installed in maritime pine plantation landscapes.
- In both countries, the relative percentage of capture per trap per week was best fitted by a logistic model with two parameters. The estimated attraction ranges were 92 m (confidence interval = 62–211 m) in France and 123 m (confidence interval = 64–491 m) in Portugal.
- The interference between paired traps thus provides a simple and robust method for estimating the attraction range of pheromone traps.
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Minoru Kasada Yoshihiro Nakashima Keita Fukasawa Gota Yajima Hiroyuki Yokomizo Tadashi Miyashita 《Population Ecology》2023,65(1):80-92
Recent increases in wildlife cause negative impacts on humans through both economic and ecological damage, as well as the spread of pathogens. Understanding the population dynamics of wildlife is crucial to develop effective management strategies. However, it is difficult to estimate accurate and precise population size over large spatial and temporal scales because of the limited data availability. We addressed these issues by first fitting a random encounter and staying time (REST) model based on camera trap data to construct an informative prior distribution for a capture rate parameter in a harvest-based Bayesian state-space model. We constructed a Bayesian state-space model that integrated administration data on the number of captured wild boar with the prior distribution of capture efficiency estimated by camera trap data. The model with informative prior distribution from the REST model successfully estimated population dynamics, whereas the model using only the administration data did not, owing to a lack of parameter convergence. We identified areas where (1) wild boars exhibit a high potential population growth rate and a high carrying capacity, (2) current trapping efforts are effectively suppressing local populations, and (3) trapping reinforcement is required to control populations in the whole region. The model could be used to predict future trends in populations under the assumptions of ongoing trapping pressure. This will help identify spatially explicit trapping efforts to achieve target population levels. 相似文献
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龚翠凤;韦伟;罗概;韩一敏;吴鹏程;何梦楠;闵清悦;付强;陈鹏 《生物多样性》2025,33(3):133-145
空间生态位分化是生物多样性维持的重要机制之一。为了解大熊猫国家公园崇州片区有蹄类的空间生态位分化情况, 本文于2021年10月至2022年3月在该区域布设了56台红外相机, 采用单季节单物种占域模型计算域内主要6种有蹄类动物的占域率, 包括毛冠鹿(Elaphodus cephalophus)、野猪(Sus scrofa)、水鹿(Rusa unicolor)、扭角羚(Budorcas taxicolor)、中华斑羚(Naemorhedus griseus)和小麂(Muntiacus reevesi), 分析其空间分布情况, 并进一步采用单季节双物种占域模型计算这些物种间的物种相互作用因子(species interaction factor, SIF)值, 探究它们的空间共存关系。结果显示: (1)毛冠鹿具有最高的空间占域率(0.61), 野猪次之(0.55), 水鹿、扭角羚和中华斑羚分别为0.44、0.41和0.11, 小麂占域率最低(0.05); (2)有蹄类动物的占域率受到环境变量的影响, 其中海拔是影响上述6种有蹄类动物分布的主要因素; (3)在空间共存关系上, 水鹿与除野猪外的其他有蹄类不存在明显回避, 毛冠鹿与野猪和扭角羚之间也不存在明显回避, 而其他物种相互之间空间分布更多呈回避关系。研究结果表明环境因素影响着崇州区域有蹄类物种的空间生态位, 同时, 物种间的空间分布格局显著影响了同域分布动物的共存机制及种间竞争关系。本研究为保护和管理大熊猫国家公园崇州片区有蹄类动物提供了重要的科学依据, 突出了在物种多样性保护中考虑空间生态位分化的重要性。 相似文献
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Lex Hiby Phil Lovell Narendra Patil N. Samba Kumar Arjun M. Gopalaswamy K. Ullas Karanth 《Biology letters》2009,5(3):383-386
The tiger is one of many species in which individuals can be identified by surface patterns. Camera traps can be used to record individual tigers moving over an array of locations and provide data for monitoring and studying populations and devising conservation strategies. We suggest using a combination of algorithms to calculate similarity scores between pattern samples scanned from the images to automate the search for a match to a new image. We show how using a three-dimensional surface model of a tiger to scan the pattern samples allows comparison of images that differ widely in camera angles and body posture. The software, which is free to download, considerably reduces the effort required to maintain an image catalogue and we suggest it could be used to trace the origin of a tiger skin by searching a central database of living tigers'' images for matches to an image of the skin. 相似文献
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Thomas R. Defler 《American journal of primatology》1996,38(4):289-302
A group of woolly monkeys (Lagothrix lagothricha), studied for 1,800 hr from June 1984 until September 1987 in the eastern Colombian Amazon, used a home range of about 760 ha, 90% of which overlapped the ranges of three other groups. Home range use varied throughout the year, correlating in part with variations in fruit production. The home range exhibited a nonexclusive “core area” in the floristically most diverse part of the home range, although the majority of the home range was entered at a much lower frequency. Within the study area woolly monkeys occurred at a density of 5.5 individuals/km2. The average day range was 2,880 m, and the average straight line distance between sleeping sites was 896 m. Day ranges differed significantly across months, but the only significant correlation tested was a positive relation with time spent “moving” in the activity budget. Comparisons with three other Amazonian sites where woolly monkeys have been studied reveal considerable variation. Soil fertility, plant community differences, and other factors seem to influence ranging patterns. © 1996 Wiley-Liss, Inc. 相似文献
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人类对于野生动物的影响复杂多样, 其中家养动物所产生的干扰往往被忽视, 例如保护区林缘社区饲养的家犬。半散放的家犬(Canis familiaris)进入野生动物栖息地, 对保护区内以大熊猫(Ailuropoda melanoleuca)为代表的野生动物可能产生重要影响。为明确家犬进入林区活动范围对大熊猫的影响, 本研究采用红外相机技术和GPS项圈无线追踪技术对甘肃白水江国家级自然保护区内家犬对大熊猫潜在栖息地范围和时间节律的影响进行研究, 利用MaxEnt模型对家犬活动范围及大熊猫潜在栖息地进行预测。结果表明: 甘肃白水江国家级自然保护区内大熊猫潜在栖息地面积为885.8 km2, 约占保护区总面积的48.2%; 家犬活动面积为861.2 km2, 约占保护区总面积的47.6%。家犬活动范围与大熊猫潜在栖息地重叠的面积约占保护区面积的28.2%, 且多集中在低海拔的常绿阔叶林。大熊猫在有家犬出现的位点和没有家犬出现的位点日活动节律具有显著差异。本研究揭示了家犬进入林区对大熊猫栖息地潜在影响的空间范围, 为保护区开展生物多样性管理提供了关键信息, 对于其他保护区具有借鉴意义。 相似文献
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Fear of predation alters prey behavior, which can indirectly alter entire landscapes. A parasite‐induced ecology of fear might also exist if animals avoid parasite‐contaminated resources when infection costs outweigh foraging benefits. To investigate whether animals avoid parasite contaminated sites, and if such avoidance balances disease costs and foraging gains, we monitored animal behavior at raccoon latrines – sites that concentrate both seeds and pathogenic parasite eggs. Using wildlife cameras, we documented over 40 potentially susceptible vertebrate species in latrines and adjacent habitat. Latrine contact rates reflected background activity, diet preferences and disease risk. Disease‐tolerant raccoons and rats displayed significant site attraction, while susceptible birds and small mammals avoided these high‐risk sites. This suggests that parasites, like predators, might create a landscape of fear for vulnerable hosts. Such non‐consumptive parasite effects could alter disease transmission, population dynamics, and even ecosystem structure. 相似文献
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Little is known about space use by Common Ravens (Corvus corax) in coastal old‐growth redwood (Sequoia sempervirens) forests in northern California despite their identification as nest predators of federally threatened Marbled Murrelets (Brachyramphus marmoratus). We used radio‐telemetry to examine home range sizes and space use of breeding Common Ravens in Redwood National and State Parks (RNSP), California, in 2009 (N = 3) and 2010 (N = 8). Mean home range size was 182.5 ha and no home ranges were >2 km from roads or human‐use areas. Ravens exhibited high site fidelity between years, and we found little overlap in the home ranges of adjacent ravens. Areas where ranges did overlap were centered on anthropogenic food sources near territory boundaries. Areas most frequently used by ravens were near roads, old‐growth edge, bare ground, and in mixed hardwood and prairie habitats; areas near human‐use areas and in old‐growth habitat were used less by ravens. Mean perch height of ravens (52 m, N = 38) in redwood trees was similar to the mean height of Marbled Murrelet nests in RNSP (48 m). In RNSP, Marbled Murrelet nests that have been located were in old‐growth forest within 2 km of roads. The attraction to anthropogenic resources with frequent use of roads and old‐growth edges and their tendency to perch high in the canopy may increase the likelihood of ravens locating and predating nests of murrelets in RNSP. 相似文献
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- Knowledge of the spatial ecology of mammalian carnivores is critical for understanding species’ biology and designing effective conservation and management interventions. We reviewed the available information about the spatial ecology of jaguars Panthera onca, pumas Puma concolor, and ocelots Leopardus pardalis, and we examined how sex and extrinsic variables affect their spatial behaviour.
- Sixty‐one articles addressing home range, home range overlap, daily net displacement (straight‐line distance between two locations on consecutive days), and/or distance of dispersal of the three species were included. Meta‐analysis, ANOVA, ANCOVA, and beta regression tests were run to analyse differences among species and sexes and to elucidate the influence of other variables, such as latitude and ecoregion, on spatial behaviour.
- Pumas had on average larger home ranges (mean ± SE: 281.87 ± 35.76 km2) than jaguars (128.61 ± 49.5 km2) and ocelots (12.46 ± 3.39 km2). Intersexual range overlap was higher than intrasexual range overlap in jaguars and pumas. Sex affected the home range size of all three species, but only influenced daily net displacement in ocelots. Ecoregion affected the home range size of all three species but did not significantly affect either the daily net displacement or the dispersal distance of pumas. Latitude affected the home range size of jaguars and pumas. It did not affect daily net displacement or dispersal distance in jaguars and pumas, but did affect daily net displacement in ocelots.
- Although there was a lack of studies in most countries for the three species, information was particularly lacking in the Neotropics for jaguars and pumas and in North America for ocelots. Researchers usually presented low sample sizes and used different methods to examine the ecological issues considered here. Homogenisation of methods is needed to clarify the ecology of these species and to allow a better understanding of the threats to their populations.