Comparing profile methods and site-occupancy modelling for the study of occurrence of an elusive species

Based on 1,053 signs of presence collected between 2002 and 2006 by a network of well-trained observers, we modelled the occurrence of the Eurasian lynx (Lynx lynx) in France using two methods. The Mahalanobis distance factor analysis (MADIFA) provided a measure of habitat suitability based on environmental covariates, and site-occupancy modelling provided estimates of both presence and detection probabilities over time. Environmental covariates included in the site-occupancy modelling markedly improved the fit of the lynx presence model. We found a strong correlation between habitat suitability scores estimated from the MADIFA and probabilities of presence estimated from the site-occupancy modelling, indicating that both methods provided a convergent assessment of lynx potential occurrence.