Vol. 47 No. 3, 2008

Factors Affecting Invasive Species Abundance: the Barbary Ground Squirrel on Fuerteventura Island, Spain

Marta López-Darias^1,* and Jorge M. Lobo²

¹Departamento de Biología Aplicada, Estación Biológica de Doñana (CSIC), Pabellón del Perú, Avenida María Luisa s/n, Sevilla, E-41013, Spain
²Departamento de Biodiversidad y Biología Evolutiva, Museo Nacional de Ciencias Naturales (CSIC), Calle José Gutiérrez Abascal 2, Madrid, E-28006, Spain.  E-mail:mcnj117@mncn.csic.es

Marta López-Darias and Jorge M. Lobo (2008) We assessed the determinants of habitat selection by the Barbary ground squirrel (Atlantoxerus getulus) at Fuerteventura (Canary Is., Spain).  We implemented general linear model (GLM) procedures to analyze the relationships between squirrel abundances and 4 kinds of variables related to the biological requirements of the species (environment, food resources, biotic interactions, and refuge/shelter).  We performed a variance partitioning analysis between the most explicative categories to explore correlation patterns.  The time of year and weather conditions of the census clearly influenced the number of individuals observed.  Shelter variables were the best correlates of both the abundance of squirrels and the number of their scat.  Although food resources were less important, the presence of certain plant species was correlated with squirrel abundance, while general environmental variables and interactions with other mammals did not affect its distribution.  These results improve our understanding of the ecology and the establishment of this highly successful introduced species, providing basic knowledge for use with future management strategies in the Canarian Archipelago.

Key words: Atlantoxerus getulus, Biological invasion, Canary Is., General linear model, Habitat selection.

*Correspondence: Tel: 34-922-256848 ext. 250.  Fax: 34-922-260135.  E-mail:mdarias@ipna.csic.es