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  1. null (Ed.)
    Integrated models combine multiple data types within a unified analysis to estimate species abundance and covariate effects. By sharing biological parameters, integrated models improve the accuracy and precision of estimates compared to separate analyses of individual data sets. We developed an integrated point process model to combine presence-only and distance sampling data for estimation of spatially explicit abundance patterns. Simulations across a range of parameter values demonstrate that our model can recover estimates of biological covariates, but parameter accuracy and precision varied with the quantity of each data type. We applied our model to a case study of black-backed jackals in the Masai Mara National Reserve, Kenya, to examine effects of spatially varying covariates on jackal abundance patterns. The model revealed that jackals were positively affected by anthropogenic disturbance on the landscape, with highest abundance estimated along the Reserve border near human activity. We found minimal effects of landscape cover, lion density, and distance to water source, suggesting that human use of the Reserve may be the biggest driver of jackal abundance patterns. Our integrated model expands the scope of ecological inference by taking advantage of widely available presence-only data, while simultaneously leveraging richer, but typically limited, distance sampling data. 
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  2. Abstract Surprising social complexity and variability have recently been documented in several mammalian species once believed to be strictly solitary, and variation in resource abundance may drive this variation in sociality. Wagner et al. (Wagner, A. P., S. Creel, L. G. Frank, and S. T. Kalinowski. 2007. Patterns of relatedness and parentage in an asocial, polyandrous striped hyena population. Molecular Ecology 16:4356–4369) reported unusual space-use patterns among female striped hyenas (Hyaena hyaena) in central Kenya, where pairwise relatedness among females increased with the geographic distance separating them. The authors suggested that this pattern, very rare among mammals, might reflect attempts by females to avoid competition with close relatives for scarce resources in areas of range overlap. Here, we compare those data to new data, documenting genetic relatedness and space use in a previously unstudied wild population of striped hyenas in southern Kenya. We tested hypotheses suggesting that resource abundance and population density affect patterns of genetic relatedness and geographic distance in this species. Our results suggest that higher per capita prey density results in relaxed competition for food, and greater social tolerance among female striped hyenas. An hypothesis suggesting lower population density in the southern population was not supported. Relaxed resource competition may also lead to female–female cooperation in the southern population; we documented for the first time behavioral evidence of den sharing by adult female striped hyenas. Our data indicate that different populations of this little-studied species exhibit behavioral plasticity, in this case, markedly different space-use patterns and patterns of spatial relatedness under different ecological conditions. 
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  3. Abstract

    Population monitoring is key to wildlife conservation and management but is challenging at the spatial and temporal extents necessary for understanding changes. Noninvasive survey methods and spatial capture–recapture (SCR) models have revolutionized wildlife monitoring by providing the means to acquire data at large scales and the framework to generate spatially explicit predictions, respectively. Despite opportunities for improved monitoring, challenges can remain in the study design and model fitting phases of an SCR approach. Here, we used a search‐encounter design with multi‐session SCR models to collect spatially indexed photographs and estimate changes in density of cheetahs between 2005 and 2013–2016 in the Masai Mara National Reserve (MMNR) in Kenya. Our SCR models of cheetah encounters suggested little change in cheetah density from 2005 to 2013–2016, with some evidence that density fluctuated annually in the MMNR. The sampling period length (5 vs. 10 months) and timing (early, late, full year) over which spatial encounters were modeled did not alter inferences about density when sample sizes were adequate (>20 spatially distinct encounters). Our average density estimate of ~1.2 cheetahs/100 km2is consistent with the impression that the MMNR provides important cheetah habitat in Africa. During most years, spatial distribution of vegetation greenness (proxy for ungulate habitat quality) accounted for important variation in encounter rates. The search‐encounter design here could be applied to other regions for cheetah monitoring. While snapshot estimates of population size across time are useful for wildlife monitoring, open population models may better identify the mechanisms behind temporal changes.

     
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  4. Abstract

    Populations of large carnivores are declining in many parts of the world due to anthropogenic activity. Some species of large carnivores, however, are able to coexist with people by altering their behavior. Altered behaviors may be challenging to identify in large carnivores because these animals are typically cryptic, nocturnal, live at low densities, and because changes in their behavior may be subtle or emerge slowly over many years. We studied the effects of livestock presence on the movements of one large carnivore, the spotted hyena (Crocuta crocuta). We fit 22 adult female spotted hyenas with GPS collars to quantify their movements in areas with and without livestock or herders present, in and around a protected area in southwestern Kenya. We investigated anthropogenic, social, and ecological effects on the speed of movement, distances traveled, long-distance movements, and extraterritorial excursions by spotted hyenas. Hyenas living primarily within the protected area, but in the presence of livestock and herders, moved faster, traveled over longer distances, and were more likely to be within their territories than did conspecifics living in areas without livestock and herders. Hyenas of low social rank were more likely than hyenas of high social rank to engage in long-distance travel events, and these were more likely to occur when prey were scarce. The movement patterns of this large African carnivore indicate a flexibility that may allow them to persist in landscapes that are becoming increasingly defined by people.

     
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