DOI: 10.5061/dryad.47d7wm3gp
title: Data from: Dracula’s ménagerie: A multispecies occupancy analysis of lynx, wildcat, and wolf in the Romanian Carpathians

description: 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 ( Ywinter= 0.76
 95% CI: 0.42-0.92; Yautumn= 0.71 CI: 0.38-0.84) and wolf
 (Ywinter= 0.60 CI: 0.34-0.78;  Yautumn= 0.81 CI:
 0.25-0.95) and lowest for wildcat (Ywinter= 0.40 CI:
 0.19-0.63; Yautumn= 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.
description: Data was collected in the Southern Carpathians, Romania, covering
 1,200 km2 in the eastern part of the Făgăraș Mountains, Piatra Craiului,
 and parts of Leaota Mountains. We divided the study area into a grid of
 2.7 km x 2.7 km cells and removed cells with more than ⅔ of their area
 exceeding 1800 m altitude and cells more than ½ of their area covered by
 urban landscape features.  From the remaining cells, we sampled every
 other cell, when it was not possible to reach a selected cell, we used an
 adjacent cell. Each sampled cell contained a trap station, randomly
 located within the cell. We conducted two seasons of monitoring: (1)
 December 17th, 2018, to March 31st, 2019 (winter) and (2) October 9th,
 2019, to January 15th, 2020 (autumn).  We installed 64 camera trap
 stations during winter, and 76 during autumn, with high spatial overlap
 between seasons. Each trap station had two opposite cameras installed at a
 height of 40 to 60 cm positioned towards animal paths. We used two camera
 models per trap station, a CuddeBack C1 Model 1279 with white flash for
 high quality color pictures in night conditions, and a Bushnell Trophy
 infrared camera. Camera traps were installed on animal trails along
 mountain ridges, mid-slopes, upper valleys, and bottom of slopes to detect
 carnivores at various altitudes/habitats. Camera traps were installed 1-2
 weeks prior to the start of monitoring to account for additional
 anthropogenic disturbance from the camera installation process. We checked
 camera trap stations every two weeks to replace batteries and SD cards. At
 each camera trap location, we recorded the presence or absences of
 anthropogenic disturbance (i.e., logging or settlements) as a binary
 variable for species detection and occurrence. We also recorded altitude
 (m) via GPS and extracted distance to stream (m), distance to settlement
 (m), and distance to roads (m) from the camera trap location using
 Geographic Information Systems (ArcGIS 10.7, ESRI, Redlands CA). Within a
 500-meter buffer around each camera trap location, we calculated the
 density of local roads (km/km2), the proportion of forested area and a
 terrain ruggedness index (TRI). We implemented a multispecies occupancy
 model of two or more interacting species (Rota et al., 2016) in program R
 3.5.1 (R Core Team, 2019) via package unmarked (Fiske & Chandler,
 2011) to explore how environmental and anthropogenic variables affect the
 marginal occupancy (occupancy without accounting for interactions with
 other species), co-occurrence (overlap in marginal occupancy between
 species), and conditional occupancy (effects of each species presence on
 other species detection and occupancy) of lynx, wildcat, and wolf in the
 Romanian Carpathians.
description: Code for this analysis is available via GitHub  We also have data for other carnivores and prey species in the area. If you are interested in using this data for an analysis please email the corresponding author.