Latrine counts to estimate wild rabbit (Oryctolagus cuniculus) density as a tool for biodiversity conservation and management

Abstract

The recovery of European wild rabbit (Oryctolagus cuniculus) populations in Spain is of great interest for wildlife conservation. Large-scale management and conservation programmes aimed to determine current population abundance.Most methods for censusing rabbits only offer estimates of relative abundance. However, we lack accurate studies about how latrine counts index is related to population density. The aim of this study is twofold: 1) to test the suitability of counting rabbit latrines as a relative abundance index and; 2) to explore if the number of latrines is a useful predictor of wild rabbit density.We compared latrine surveys conducted in 2 km-length paths with density estimates obtained from distance-based estimates. The study was conducted during two years in central Spain in mixed agriculture-woodland landscapes. Sites covered all potential range of rabbit densities in natural landscapes. Density estimates were obtained by using Distance software.We used type II major axis regression to evaluate the relationship between rabbit density and latrine counting. The predictive ability of the regression equation was performed by several predictive metrics.Results show that the number of latrines counted is a very good abundance index. We also found that latrine counts had a high predictive power to estimate rabbit density. Therefore, latrine surveys are not only a proxy of abundance, but can be used as a cost-effective tool to estimate rabbit population density at low and intermediate densities, which are the most important for the conservation practitioners. Furthermore, the method needs to be tested in other seasons and habitats to prove its generality.