Seasonal and anthropogenic effects on niche overlap and habitat selection by sympatric bears (Ursus arctos marsicanus) and wolves (Canis lupus) in a human-dominated landscape

During 2005−2010, we investigated interactions between brown bears (n=19) and wolves (n=7) by means of GPS-telemetry in a long-established national park in the central Apennines, Italy, where bears and wolves always coexisted close to humans. Based on K-select analysis and a randomization approach we assessed the extent of overlap between the species' niches on a seasonal basis. In additon, we used multi-species Resource Selection Functions (RSFs) at the 3rd-order selection (i.e., home range level) to investigate their habitat choice taking into account an intraguild predictor (i.e., the probability of occurrence n te other species). Bears and wolves clearly segregated in fall but not during summer, when the overlap between their realized niches suggests a convergent adaptation to a seasonal peak of anthropogenic pressure. Using multi-species RSFs, however, habitat choice by bears and wolves differed also when their niches overlapped, and their probability of occurrence was reciprocally affected.

Methods
The dataset refers to environmental and anthropogenic variables, derived in a GIS environment, in points (i.e., locations) used ("Pres"=1) and available ("Pres"=0) to sympatric adult bears (Ursus arctos marsicanus, n=19) and wolves (Canis lupus, n=7) living in the Abruzzo Lazio and Molise National park, central Italy, from 2005 to 2010.

Animal locations ("Pres"=1) were recorded by means of Global Positionin System (GPS) collars, whereas available points ("Pres"=0) were randomly selected at a density of 10 locations/km2 within ther seasonal home range to prepresent resources available. GPS locations were recorded at 3-hr intervals, but their coordinates are omitted from the files due to serurity reason (Apennine brown bears are Critically Endandered according to the IUCN Regional Red List Criteria).

The dataset is organized in 8 diferent Excel files, one for each species and season, as indicated by their names. The data have been used to conduct (1) K-select seasonal analyses to assess niche overlap between bears and wolves living sympatrically in the central Apennines (Italy), and (2) to develop multi-species Resource Selection Functions to investigate habitat selection at the 3rd order of selectin (i.e., within the home range).

R codes to run the analyses are also made available.