Data from: Dracula's ménagerie: A multispecies occupancy analysis of lynx, wildcat, and wolf in the Romanian Carpathians

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.

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.

We used camera trap data from two seasons in Transylvanian forests to assess occupancy and co-occurrence of carnivores using multispecies occupancy models.

Mean occupancy in the study area was highest for lynx ( Y_winter= 0.76 95% CI: 0.42-0.92; Yautumn= 0.71 CI: 0.38-0.84) and wolf (Y_winter= 0.60 CI: 0.34-0.78;  Y_autumn= 0.81 CI: 0.25-0.95) and lowest for wildcat (Y_winter= 0.40 CI: 0.19-0.63; Y_autumn= 0.52 CI: 0.17-0.78)

We found that marginal occupancy predictors for carnivores varied between seasons. We also found differences in predictors of co-occurrence between seasons for both lynx-wolf and wildcat-wolf co-occurrence. For both seasons, we found that conditional occupancy probabilities of all three species were higher when another species was present.

Our results indicate that while there are seasonal differences in predictors of occupancy and co-occurrence of the three species, co-occurrence in our study area is high, and is dependent on the existence of continuous, relatively undisturbed forests.

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.