Resource partitioning between kit foxes (Vulpes macrotis) and coyotes (Canis latrans): a comparison of historical and contemporary dietary overlapUnder conditions leading to coexistence, competition with a dominant species may limit the distribution and density of a subordinate carnivore (Hardin 1960;Schoener 1983; Glen and Dickman 2008;Sidorovich et al. 2010), which can make the population less resilient to changes in habitat or resource availability. Thus, the ability to minimize competition through resource partitioning may be critical for the long-term persistence of specialist carnivore populations facing novel competitive pressures.Resource partitioning is a multidimensional process involving temporal, spatial, and/or dietary shifts in a species' resource use, which lessens niche overlap among species (Schoener 1974; Garneau et al. 2007; Kamler et al. 2012) and reduces negative encounters between were believed to be on increasing and decreasing long-term trajectories, respectively (Arjo et al. 2007). Consequently, we hypothesized we would see an overall decrease in dietary overlap between the two species, reflecting increased competition for prey and, accordingly, an increased degree of dietary resource partitioning. It has been hypothesized that water is a limiting factor in this region (Arjo et al. 2007), and that kit foxes and coyotes select for prey that will maximize water intake (Golightly and Ohmart 1984; Kozlowski et al. 2012). We predicted that coyotes would limit kit fox access to higher-quality dietary prey, such as leporids, which contain higher water content per capture than smaller mammals, such as kangaroo rats (species of genus Dipodomys Gray, 1841) and other rodents (species of the order Rodentia Bowdich, 1821), and non-mammalian prey (e.g., insects, reptiles, birds-Pond 1978). We predicted that kit foxes would respond by increasing their use of small mammals and non-mammalian prey. Materials and methods Study areaThis study was conducted in the Great Basin Desert of western Utah. Sampling occurred on the U.S Army's Dugway Proving Ground and surrounding federal lands managed by the U.S. Dietary overlap was calculated using the Morisita-Horn Similarity Index (hereafter, M-H Index-Horn 1966), in which overlap was based on the proportion of prey classes in the diet, and was measured on a scale of 0 (no dietary overlap) to 1 (complete dietary overlap). All 11 dietary classes were included in measurements of overlap and diversity. Seasonal and annual dietary overlap was assessed within each canid species between the contemporary and historical periods.Dietary overlap was also assessed between kit foxes and coyotes for the contemporary sampling period. Breadth of dietary diversity for contemporary samples was calculated using the ShannonWeiner Diversity Index (hereafter, H'-Shannon 1948). Dietary diversity was measured both annually and for winter and summer sampling periods, and differences in diversity were tested for significance using Hutcheson's t-test (Hutcheson 1970). Differences in...

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Connectivity among wildlife populations facilitates exchange of genetic material between groups. Changes to historical connectivity patterns resulting from anthropogenic activities can therefore have negative consequences for genetic diversity, particularly for small or isolated populations. DNA obtained from museum specimens can enable direct comparison of temporal changes in connectivity among populations, which can aid in conservation planning and contribute to understanding of population declines. However, museum DNA can be degraded and only available in low quantities, rendering it challenging for use in population genomic analyses. Applications of genomic methodologies such as targeted sequencing address this issue by enabling capture of shared variable sites, increasing quantity and quality of recovered genomic information. We used targeted sequencing of Ultra-conserved Elements (UCEs) to evaluate potential changes in connectivity and genetic diversity of roseate terns (Sterna dougallii) with a breeding distribution in the Northwestern Atlantic and the Caribbean. Both populations experienced range contractions and population declines due to anthropogenic activity in the 20th century, which has the potential to alter historical connectivity regimes. Instead, we found that the two populations were differentiated historically as well as contemporaneously, with little evidence of migration between them for either time period. We also found no evidence for temporal changes in genetic diversity, although these interpretations may have been limited due to sequencing artifacts caused by the degraded nature of the museum samples. Population structuring in migratory seabirds is typically reflective of low rates of divergence and high connectivity among geographically segregated subpopulations. Our contrasting results suggest the potential presence of ecological mechanisms driving population differentiation, and highlight the value of targeted sequencing on DNA derived from museum specimens to uncover long-term patterns of genetic differentiation in wildlife populations.