Marissa Dyck

and 4 more

The recovery of mammalian species in the US Midwest through natural recolonization constitutes a conservation success story, yet management remains challenging due to many unknowns related to population dynamics and abundance. Abundance is a critical parameter for management decisions, and estimating the density and abundance of elusive species, such as terrestrial carnivores, remains challenging despite recent technological advances. In this study, we evaluated density and abundance of a recovering carnivore species, the bobcat (Lynx rufus) in two areas of Ohio using non-invasive DNA from scat. The target areas in eastern and southern Ohio have been shown to have uneven dynamics and recolonization success and we expected that this would be reflected in differences in density and abundance. We collected 298 bobcat scats between July 2018 and April 2019 on 150 km of repeated transects. Of these, 102 scats were successfully genotyped, and 55 individuals were identified (33 in eastern Ohio and 22 in southern Ohio). Using Spatially Explicit Capture-Recapture models, we estimated 17.9 ± 4.3 and 11.3 ± 2.9 bobcats/100 km2 in eastern and southern Ohio study areas, respectively. Our results support prior telemetry data which indicated that bobcats in eastern Ohio had smaller home-ranges than bobcats in southern Ohio, and thus could support a higher density of individuals. The higher densities were similar to other eastern US populations and are much higher than other Midwestern recovering populations. Our results provide a snapshot of the population status and can be used to determine sustainable management strategies for Ohio’s bobcat population

Marissa Dyck

and 3 more

1. The recovery of terrestrial carnivores in Europe is a conservation success story. Initiatives focused on restoring top predators, require information on how resident species may interact with the re-introduced species as their interactions have the potential to alter food webs, yet such data are scarce for Europe. 2. In this study, we assessed patterns of occupancy and interactions between three carnivore species in the Romanian Carpathians. Romania houses one of the few intact carnivore guilds in Europe, making it an ideal system to assess intraguild interactions, and serve as a guide for reintroductions elsewhere. 3. We used camera trap data from two seasons in Transylvanian forests to assess occupancy and co-occurrence of carnivores using multispecies occupancy models. 4. Mean occupancy in the study area was highest for lynx ( winter= 0.76 95% CI: 0.42-0.92; autumn= 0.71 CI: 0.38-0.84) and wolf (winter= 0.60 CI: 0.34-0.78; autumn= 0.81 CI: 0.25-0.95) and lowest for wildcat (winter= 0.40 CI: 0.19-0.63; autumn= 0.52 CI: 0.17-0.78) 5. We found that marginal occupancy predictors for carnivores varied between seasons. We also found differences in predictors of co-occupancy between seasons for both lynx-wolf and wildcat-wolf co-occupancy. For both seasons, we found that conditional occupancy probabilities of all three species were higher when another species was present. 6. Our results indicate that while there are seasonal differences in predictors of occupancy and co-occupancy of the three species, co-occurrence in our study area is high, and is dependent on the existence of continuous, relatively undisturbed forests. 7. Terrestrial carnivore recovery efforts are ongoing worldwide. Insights into interspecific relations between carnivore species are critical when considering the depauperate communities they are introduced in. Our work showcases that apex carnivore coexistence is possible, but dependent on protection afforded to forest habitats and their prey base.