Habitat and food preferences of European rabbits in core and edge populations along the invasion front Patagonia-Monte, Argentina

Abstract

The European rabbit Oryctolagus cuniculus is an exotic herbivorous mammal undergoing an active phase of geographical expansion in arid ecosystems of Argentina. The Adaptive Flexibility Hypothesis states that populations at the range edge (new populations) will exhibit greater flexibility in use of resources compared to populations located in the range core (older populations). The objective of this work was to compare the rabbit use of spatial and trophic resources in relation to establishment time of their populations. The sampling was carried out for 2 years (2017, 2018) in sites with different establishment times for rabbit populations. Random sampling stratified by type of habitat was applied using 115 fixed strip transects of 1,000 m 2 laid out across the study areas. Fresh rabbit signs were recorded in each transect, and environmental and anthropic variables were measured. Our results show that the individuals from the range edge are more selective in the use of habitat than those from the range core. At the microhabitat level, we observed a pattern in the particular components of habitat use by rabbits mainly linked to food availability and proximity to water. From a trophic perspective, rabbits could show flexible adjustment to novel conditions environments in the range edge. The variability in resource use by the European rabbit confirms its ecological flexibility, pivotal for their advance toward new environments in Argentina.