Christopher T. Rota

Objective: Reproduction and recruitment represent distinct demographic processes that may independently limit establishment and spread of an invasive species. We evaluated reproduction and recruitment success of Bighead Carp Hypophthalmichthys nobilis and Silver Carp H. molitrix in the Ohio River basin across multiple spatial and temporal scales to identify potential demographic bottlenecks. Methods: We assessed detection/nondetection data on Bighead Carp and Silver Carp eggs/larvae and young of the year (age 0) to provide information on these species’ reproduction and recruitment, respectively. Data were assessed at reach-level (i.e., pool) and site-level spatial scales and at annual and intra-annual temporal scales throughout the Ohio River basin, relating patterns of egg/larval and young-of-the-year occurrence to adult relative abundance, hydrologic conditions, and nursery habitat availability. Results: Estimated occurrence of Bighead Carp eggs/larvae and young of the year was inconsistent throughout the study area, suggesting limited establishment success in the Ohio River. Silver Carp egg/larval persistence probability was primarily associated with adult densities rather than variation in flow or temperature, and eggs were estimated to occur across a large portion of the basin. However, Silver Carp young-of-the-year occurrence appeared to be spatially restricted. Annual pool and intra-annual site young-of-the-year persistence probability was correlated with the availability of nursery habitat at both scales. Young of the year were consistently detected at only one location, a floodplain lake (Hovey Lake) in the John T. Myers pool, indicating the presence of a potential localized source population in this location. Conclusions: Silver Carp eggs/larvae were detected across much of the invaded portion of the Ohio River, suggesting that reproduction is widespread. However, young-of-the-year occurrence was most strongly associated with nursery habitat. In the Ohio River, the lack of widespread nursery habitat may be limiting the recruitment success of young-of-the-year Silver Carp into the population, potentially creating a demographic bottleneck that constrains their spread in this basin.

Population density is an important measure when monitoring wildlife populations. Various methods have been used to estimate density, including spatial capture‐recapture (SCR) models applied to camera trapping data. Although density estimates from SCR models fit to data from unmarked animals can be considerably imprecise, ancillary data can potentially improve precision of density estimates. We estimated densities of unmarked white‐tailed deer ( Odocoileus virginianus ) populations across 3 study areas in West Virginia, USA. We used SCR methods in a Bayesian framework and incorporated home range data from global positioning system (GPS) collared deer to inform model parameters. Mean population density estimates were 10 deer/km ² in the central study area, 9 deer/km ² in the eastern study area, and 8 deer/km ² in the western study area. Although we do not know the true population density, our estimates are comparable to regional estimates from other studies. Density estimates from SCR models fit to data from unmarked animals are sensitive to model parameters, evidenced by the variation in estimated detection rates (0.28–0.41 detections/day) and home range size (73–98 ha) across our study areas. Although we demonstrate this technique with ancillary GPS data, other forms of ancillary data, including informative prior distributions, can be used to improve precision of density estimates obtained from completely unmarked animal populations. This method could be applied to a wide range of species, provided the appropriate ancillary data are available.

The combined effects of climate and landscape change are likely to be contributing to widespread and pervasive declines in forest bird populations. Individual species responses vary across climatic niches and habitat requirements, but bird communities and populations in montane systems may be particularly vulnerable to climate anomalies. Previous syntheses have reviewed evidence for impacts of climate change on bird species in general, in temperate regions and in Holarctic mountain ranges. Here, we propose that the Appalachian Mountains of eastern North America serve as an instructive case study due to their distinct combination of extensive temperate broadleaf forest cover, predominantly northeast–southwest orientation that bridges two major biomes and a bird assemblage that contains trailing‐edge populations of species that predominantly breed in the boreal forest. Our goal was to review the contemporary and potential future effects of both climate and land cover change on forest birds breeding in the Appalachian Mountains. Specifically, we focused on synthesizing documented and predicted changes in bird species distributions, populations and communities in response to changes in climate and land cover across this mountain range. We further compared our findings with trends from other mountain ranges across the world to assess commonalities and differences. Although there was limited literature from the Appalachian Mountains that incorporated both climate and land cover variables in models of forest bird responses, several results were consistent with studies from other montane systems, including vulnerability of cold‐associated species to warming temperatures and stronger effects predicted for future scenarios with higher greenhouse gas emissions. In addition, there were no prevailing trends that differed greatly from other mountain ranges, but potential extirpations of cold‐associated species varied along latitudinal gradients within the Appalachian Mountains region, and there was nuance in how changes in land cover and habitat conditions modified forest bird responses to climate change. We concluded our review by identifying key knowledge gaps, suggesting future directions for research and highlighting the conservation implications for forest birds in the Appalachian Mountains.

Eastern wild turkeys ( Meleagris gallopavo silvestris ) in northeastern South Dakota, USA, appeared to be expanding soon after reintroduction in the 1990s. However, recent hunter success trends suggest a population decline in the region. While the cause of the apparent decline was unclear, out of an abundance of caution managers closed the fall either‐sex hunting season throughout much of the region in 2014. An investigation into factors driving wild turkey population growth within northeastern South Dakota was needed to determine the most effective management strategies for increasing abundance. We incorporated age‐class specific estimates of female survival and lower‐level reproductive parameters into a female‐only, 2‐stage pre‐breeding birth‐pulse model to project the population growth rate. Additionally, we performed perturbation analyses, including a life‐stage simulation analysis, and simulated variation in each vital rate to assess effects of changes in demographic parameters on population growth. The finite rate of change indicates this population was declining‐to‐stable (λ = 0.804; 95% CI = 0.597, 1.006). Perturbation analyses indicate population growth was most greatly affected by changes in female survival; however, simulated variations suggest that low poult survival may be limiting population growth as well. Management interventions that simultaneously improve female and poult survival, such as increasing availability of brood‐rearing cover, have the greatest likelihood of achieving population growth and improving hunting opportunities in the region.

In forested landscapes of the Central Appalachians, wildlife openings are often created and maintained by land managers to provide early‐successional habitat and food resources for game species, such as wild turkey ( Meleagris gallopavo ), ruffed grouse ( Bonasa umbellus ), and American woodcock ( Scolopax minor ). Although management may focus on these regionally important game birds, wildlife openings can also benefit a myriad of avian species and guilds, depending on local habitat features and landscape‐level factors. Yet little effort has been made to investigate how to optimally manage wildlife openings to attract a full spectrum of avifauna throughout spring and summer and to maximize richness across habitat guilds. Therefore, the purpose of this study was to identify the characteristics of wildlife openings that support target game birds and a diversity of breeding and post‐breeding songbirds. Specifically, we investigated the effects of local habitat attributes, opening size, management decisions, and landscape context on multi‐species occupancy of 3 game birds (wild turkey, ruffed grouse, and American woodcock) during the game bird courtship season and songbird guild richness during the breeding and post‐breeding seasons. During April–August 2019–2021, we used species‐specific and community‐wide point count surveys, game cameras, acoustic recording units, and transect surveys to sample avian communities in 335 wildlife openings within the Monongahela National Forest in West Virginia, USA. We incorporated multiple data sources for game bird occurrence into multi‐species occupancy models, which were constructed within a Bayesian framework, and we used Bayesian hierarchical community models to calculate breeding and post‐breeding songbird guild richness, followed by generalized linear mixed effects models to assess relationships with wildlife opening characteristics. Results from our game bird analyses indicated that wild turkey, ruffed grouse, and American woodcock occupancy probabilities were best explained by predictor variables relating primarily to management actions, such as mowing frequency, and secondarily to size and local habitat attributes of the wildlife openings, such as area, percent sapling cover, and elevation. Songbird guild richness also responded to area and elevation, with additional influence from predictor variables relating to landscape context. The songbird model results further indicated that it is feasible to manage wildlife openings for the mutual benefit of different species groups across seasons. Ultimately, these findings can be integrated into the design and management of wildlife openings to support target game bird populations and promote avian diversity in forest ecosystems.

Large ungulates across the world are threatened with extinction due to habitat loss, land use change, and other anthropogenic pressures. While conservation measures are critical, for many populations the implementation of conservation measures is often not practical, either due to a lack of information on the species' biology or their conservation status. Here we consider 2 large ungulates, the roan ( Hippotragus equinus ) and sable ( H. niger ) antelopes, occurring in Mudumu National Park (MNP) Namibia, for which data on populations trends and habitat use are largely unknown. Here, we used camera trapping data collected in the dry and wet seasons between March and September 2021 in visit frequency models to understand the relationship between habitat variables and the distribution dynamics of roan and sable over time at MNP. Our results showed that roans in the wet season were detected more at sites with increased grass cover and detected less at sites near the Kwando River. In the dry season, roans were detected more at sites with increased grass cover and more termite mounds but detected less at sites near the Kwando River. In the wet season, sables were detected more at sites with fewer termite mounds. In the dry season, sables were detected more at sites with increased grass cover. We hypothesized that roan and sable use fewer areas near permanent water to avoid high predator densities and high grazing intensity by dense herds of short‐grass grazers. The study findings are useful knowledge on 2 threatened ungulates and will be used to inform and develop comprehensive conservation programs and strategies that aim to lower the risk of extinction for roan and sable at a Namibian protected area.

Aim: The assembly of species into communities and ecoregions is the result of interacting factors that affect plant and animal distribution and abundance at biogeographic scales. Here, we empirically derive ecoregions for mammals to test whether human disturbance has become more important than climate and habitat resources in structuring communities.Location: Conterminous United States.Time Period: 2010–2021.Major Taxa Studied: Twenty‐five species of mammals.Methods: We analysed data from 25 mammal species recorded by camera traps at 6645 locations across the conterminous United States in a joint modelling framework to estimate relative abundance of each species. We then used a clustering analysis to describe 8 broad and 16 narrow mammal communities.Results: Climate was the most important predictor of mammal abundance overall, while human population density and agriculture were less important, with mixed effects across species. Seed production by forests also predicted mammal abundance, especially hard‐mast tree species. The mammal community maps are similar to those of plants, with an east–west split driven by different dominant species of deer and squirrels. Communities vary along gradients of temperature in the east and precipitation in the west. Most fine‐scale mammal community boundaries aligned with established plant ecoregions and were distinguished by the presence of regional specialists or shifts in relative abundance of widespread species. Maps of potential ecosystem services provided by these communities suggest high herbivory in the Rocky Mountains and eastern forests, high invertebrate predation in the subtropical south and greater predation pressure on large vertebrates in the west.Main Conclusions: Our results highlight the importance of climate to modern mammals and suggest that climate change will have strong impacts on these communities. Our new empirical approach to recognizing ecoregions has potential to be applied to expanded communities of mammals or other taxa.

A worldwide increasing demand for renewable and non‐renewable energy resources has been ongoing since the mid‐1970s and is projected to increase for the next 2 decades. The effects of oil and natural gas development on wildlife mortality risk may play an important role in mule deer (Odocoileus hemionus) population dynamics. We evaluated the potential effects of oil and natural gas development on mortality risk of mule deer in western North Dakota and eastern Montana, USA. We assessed adult and juvenile female mule deer mortality risk with Poisson point process models using 265 deer fitted with global positioning system (GPS) radio‐collars that were deployed from 2013–2016. Mortality covariates included proportion of area disturbed by oil and natural gas development, distance to oil and natural gas development, distance to roads, temperature, snow depth, normalized difference vegetation index (NDVI), and age of deer. During the study there was no effect of oil and natural gas development or roads on mule deer mortality, though <1% of all deer locations were within 500 m of active drilling rigs. Mule deer mortality was greatest in winter and spring, and positively related to temperature during these seasons. Estimated annual adult survival probability was 0.79 (95% CI = 0.71–0.85). Given the strong influence of season and temperature variables on mortality risk, weather had the strongest influence on mule deer mortality during this study. Although we did not detect an effect of energy development on mule deer mortality, effects on space use resulting from development could influence deer dynamics in the region through displacement and could occur over longer time scales than we evaluated. This study can be used in pre‐development planning in a risk assessment framework to minimize effects of development on mule deer.

Wildlife space use is a key component to consider when determining effective conservation and management practices. Home range size and resource selection can vary temporally and spatially depending on mortality risks in the area and access to food resources. Lands used for coal mining can contain unique mortality risks and food resources for American black bears ( Ursus americanus ) relative to surrounding landscapes due to hunting restrictions, vegetation planted as part of the reclamation process, and other anthropogenic food resources. We examined the influence of mining sites on resource selection of female black bears in southern West Virginia, USA, during 2007 and 2008. We estimated home range size with Brownian Bridge movement models and evaluated variation in home range size with mixed‐effects linear regression. We evaluated resource selection with mixed‐effects Poisson point process models. On mine sites, the mean 95% home range for female black bears was 1,996 ha (SD = 2,633) in the autumn and 544 ha (SD = 238) in the spring, and on non‐mine sites the mean 95% home range was 1,926 ha (SD = 1,292) in the autumn and 771 ha (SD = 480) in the spring. Our resource selection model indicated black bears used nonhunting zones associated with mine lands much greater than their availability, and that black bears in mine areas disproportionately used areas in close proximity to anthropogenic structures. Interannual variation in home range size was likely associated with mast conditions, because smaller home ranges were associated with high mast production. Our data suggest black bears may be using non‐hunting zones within mine lands as refugia from hunting and are using anthropogenic food sources available at refuse sites on mine lands, which may increase regional black bear populations in areas with high mining activity.