Assessment of methods for estimating wild rabbit population abundance in agricultural landscapes
Various methods have been used to estimate rabbit abundance, but comparisons of standard methods are still lacking, and thus, results remain roughly comparable across studies. Ideally, a method should be applicable over a wide range of situations, such as differing abundances or habitat types. Comparisons of methods are required to evaluate the benefits of each of them, and survey methods should be validated for the conditions in which they will be used. In this study, we compare the performance of direct methods (kilometric abundance index and distance sampling) in two seasons and at two times of day (dusk and night) for estimating wild rabbit abundances in agricultural landscapes. Estimates based on direct methods were highly correlated and detected similar seasonal population changes. Night counts provided better estimates than did dusk counts and exhibited more precision. Results are discussed within the context of rabbit behaviour and their implications for rabbit population surveys.
KeywordsLagomorphs Oryctolagus cuniculus Distance sampling Kilometric abundance index
Funding was provided by FEDENCA. ICB was supported by a PhD fellowship from the Spanish Ministry of Science and Innovation. PA is currently enjoying a Juan de la Cierva research contract awarded by the Spanish Ministry of Science and Innovation and is supported by the project CGL2006-09567/BOS. We extend special thanks to F. Cirilli, J.D. Jimena, J.M. Guerrero, and P. Rodríguez-Hidalgo for assistance in the field. We are also grateful to C.G. Bueno and H. Rödel for providing useful comments, S. Petrovan for useful discussions, B. MacWhirter for improving the English version, and A. Ríos for his hospitality.
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