BackgroundThe greater sage-grouse (Centrocercus urophasianus) is a ground-nesting bird from the Northern Rocky Mountains and a species at risk of extinction in in multiple U.S. states and Canada. Herein we report results from a proof of concept that mitochondrial and nuclear DNAs from mammalian predator saliva could be non-invasively collected from depredated greater sage-grouse eggshells and carcasses and used for predator species identification. Molecular forensic approaches have been applied to identify predators from depredated remains as one strategy to better understand predator–prey dynamics and guide management strategies. This can aid conservation efforts by correctly identifying predators most likely to impact threatened and endangered species. DNA isolated from non-invasive samples around nesting sites (e.g. fecal or hair samples) is one method that can increase the success and accuracy of predator species identification when compared to relying on nest remains alone.ResultsPredator saliva DNA was collected from depredated eggshells and carcasses using swabs. We sequenced two partial fragments of two mitochondrial genes and obtained microsatellite genotypes using canid specific primers for species and individual identification, respectively. Using this multilocus approach we were able to identify predators, at least down to family, from 11 out of 14 nests (79 %) and three out of seven carcasses (47 %). Predators detected most frequently were canids (86 %), while other taxa included rodents, a striped skunk, and cattle. We attempted to match the genotypes of individual coyotes obtained from eggshells and carcasses with those obtained from fecal samples and coyotes collected in the areas, but no genotype matches were found.ConclusionPredation is a main cause of nest failure in ground-nesting birds and can impact reproduction and recruitment. To inform predator management for ground-nesting bird conservation, accurate identification of predator species is necessary. Considering predation can have a high impact on recruitment, predation events are very difficult to observe, and predator species are difficult to identify visually from nest remains, molecular approaches that reduce the need to observe or handle animals offer an additional tool to better understand predator–prey dynamics at nesting sites.Electronic supplementary materialThe online version of this article (doi:10.1186/s13104-015-1797-1) contains supplementary material, which is available to authorized users.

Nest survival, along with female survival and chick survival, is the most important vital rates to population growth of greater sage‐grouse (Centrocercus urophasianus; sage‐grouse). We used global positioning system and very high‐frequency transmitters on female sage‐grouse to identify 204 nests and monitor incubation on 5 sites in the Bighorn Basin, Wyoming from 2011 to 2014; we determined nest fate and identified predators with camera traps. We used an information‐theoretic approach to compare 6 a priori nest survival models. Nest survival was best described by a model that included differences across study sites and ranged from 0.20 ± 0.01 (SE) to 0.56 ± 0.05. Coyotes (Canis latrans) were the apex predator, and coyotes were removed annually by United States Department of Agriculture, Animal and Plant Inspection Service, Wildlife Services on 4 of 5 sites to reduce depredation to livestock and big game (truex¯ removal = 0–0.56 coyotes/km2/site). Coyotes were the greatest contributor to nest failure, followed by common ravens (Corvus corax), abandonment, and female mortality. The direct effect of nest depredation by coyotes was greater than other reported sage‐grouse studies, yet our nest survival rates were consistent with others reported throughout the species range. Coyote removal did not appear to have indirect effects, such as a mesopredator release, on nest survival. Nest survival was least on a site where coyotes and ravens depredated nests at nearly the same rate, and where ravens were observed nesting on infrastructure close to nesting sage‐grouse. © 2017 The Wildlife Society.

Understanding the types and magnitude of human-caused mortality is essential for maintaining viable large carnivore populations. We used a database of cause-specific mortality to examine how hunting regulations and landscape configurations influenced human-caused mortality of North American gray wolves (Canis lupus). Our dataset included 21 studies that monitored the fates of 3564 wolves and reported 1442 mortalities. Human-caused mortality accounted for 61% of mortality overall, with 23% due to illegal harvest, 16% due to legal harvest, and 12% the result of management removal. The overall proportion of anthropogenic wolf mortality was lowest in areas with an open hunting season compared to areas with a closed hunting season or mixed hunting regulations, suggesting that harvest mortality was neither fully additive nor compensatory. Proportion of mortality from management removal was reduced in areas with an open hunting season, suggesting that legal harvest may reduce human-wolf conflicts or alternatively that areas with legal harvest have less potential for management removals (e.g., less livestock depredation). Proportion of natural habitat was negatively correlated with the proportion of anthropogenic and illegal harvest mortality. Additionally, the proportion of mortality due to illegal harvest increased with greater natural habitat fragmentation. The observed association between large patches of natural habitat and reductions in several sources of anthropogenic wolf mortality reiterate the importance of habitat preservation to maintain wolf populations. Furthermore, effective management of wolf populations via implementation of harvest may reduce conflict with humans. Effective wolf conservation will depend on holistic strategies that integrate ecological and socioeconomic factors to facilitate their long-term coexistence with humans.