Effects of post‐release movements on survival of translocated sage‐grouse

The potential influence of genome-wide adaptive divergence on conservation translocation outcome in an isolated greater sage-grouse population

Conservation translocations are an important conservation tool commonly employed to augment declining or reestablish extirpated populations. One goal of augmentation is to increase genetic diversity and reduce the risk of inbreeding depression (i.e., genetic rescue). However, introducing individuals from significantly diverged populations risks disrupting coadapted traits and reducing local fitness (i.e., outbreeding depression). Genetic data are increasingly more accessible for wildlife species and can provide unique insight regarding the presence and retention of introduced genetic variation from augmentation as an indicator of effectiveness and adaptive similarity as an indicator of source and recipient population suitability. We used 2 genetic data sets to evaluate augmentation of isolated populations of greater sage-grouse (Centrocercus urophasianus) in the northwestern region of the species range (Washington, USA) and to retrospectively evaluate adaptive divergence among source and recipient populations. We developed 2 statistical models for microsatellite data to evaluate augmentation outcomes. We used one model to predict genetic diversity after augmentation and compared these predictions with observations of genetic change. We used the second model to quantify the amount of observed reproduction attributed to transplants (proof of population integration). We also characterized genome-wide adaptive divergence among source and recipient populations. Observed genetic diversity (HO = 0.65) was higher in the recipient population than predicted had no augmentation occurred (HO = 0.58) but less than what was predicted by our model (HO = 0.75). The amount of shared genetic variation between the 2 geographically isolated resident populations increased, which is evidence of periodic gene flow previously assumed to be rare. Among candidate adaptive genes associated with elevated fixation index (FST) (143 genes) or local environmental variables (97 and 157 genes for each genotype-environment association method, respectively), we found clusters of genes with related functions that may influence the ability of transplants to use local resources and navigate unfamiliar environments and their reproductive potential, all possible reasons for low genetic retention from augmentation.

Assessing Global Efforts in the Selection of Vertebrates as Umbrella Species for Conservation

The umbrella-species strategy has been proposed as an attainable tool to achieve multi-species and community conservation with limited investment. There have been many umbrella-related studies since the concept's inception; thus, a summary of global study efforts and recommended umbrella species is important for understanding advances in the field and facilitating conservation applications. Here, we collated 213 recommended umbrella species of terrestrial vertebrates from 242 scientific articles published during 1984-2021 and analyzed their geographic patterns, biological features, and conservation statuses to identify global trends in the selection of umbrella species. We found a considerable geographic bias: most studies and, consequently, recommended umbrella species are from the Northern Hemisphere. There is also a strong taxonomic bias, with grouses (order Galliformes) and large carnivores being the most popular umbrella species and amphibians and reptiles being largely overlooked. In addition, wide-ranging and non-threatened species were frequently recommended as umbrella species. Given the observed biases and trends, we caution that appropriate species need to be chosen for each location, and it is important to confirm that popular, wide-ranging species are effective umbrella species. Moreover, amphibians and reptiles should be investigated for their potential as umbrella species. The umbrella-species strategy has many strengths and, if applied appropriately, may be one of the best options in today's conservation research and funding landscape.

Seasonal habitat suitability models for a threatened species: the Gunnison sage-grouse

Abstract ContextThe Gunnison sage-grouse (Centrocercus minimus) has experienced range-wide declines and has been listed as Threatened by the USA Fish and Wildlife Service to receive protections under the USA Endangered Species Act. A draft Recovery Plan was recently completed. No seasonal habitat models have been developed for the small isolated populations. AimsTo develop a habitat suitability model that was collaboratively developed between modellers and conservation practitioners to predict the probability of use by Gunnison sage-grouse during the breeding and summer seasons in designated occupied critical habitat, and extrapolate to adjacent designated unoccupied critical habitat. MethodsWe captured, marked and tracked Gunnison sage-grouse in nine different studies spanning 25 years. We used a suite of biotic, abiotic and vegetation local-level and population-scale covariates in a use-available resource selection function to develop models that predict the probability of use by Gunnison sage-grouse. Key resultsWe used 9140 Gunnison sage-grouse locations from 406 individual birds to develop nine resource selection models for occupied habitat and extrapolated model predictions to adjacent unoccupied critical habitat in five small isolated Gunnison sage-grouse populations. A majority of our models validated well. ConclusionsWe report the first two-season resource use-based habitat suitability models for five of six small isolated Gunnison sage-grouse populations. Because of the unique habitat use by Gunnison sage-grouse in each population, we recommend that resource managers strategically target management actions in individual populations and avoid ‘one-size-fits-all’ habitat management prescriptions. ImplicationsOur models will assist managers in the identification of seasonal habitats within populations to target management actions for Gunnison sage-grouse recovery.