Predicting the future distribution of the Barbary ground squirrel (Atlantoxerus getulus) under climate change using niche overlap analysis and species distribution modeling

This study combines niche overlap analysis with species distribution modeling (SDM) to examine the niche dynamics of Atlantoxerus getulus, a ground squirrel native to Morocco and Algeria that has been introduced to the Canary Islands. We compiled 1272 records of A. getulus in its native and exotic ranges and five bioclimatic variables for present and future climate conditions for the years 2050 and 2070. We assessed the ecological niche of the species using exploratory and ordination analyses, followed by the prediction of its distribution using the SpatialMaxent model. Our results showed that the niches of A. getulus exhibited equivalence (p > 0.05) and significant similarity (p < 0.05) between the native and exotic ranges. No observed niche expansion in the exotic area is shown to be associated with complete niche stability. However, 90% of the niche in the Canary Islands remains unfilled, suggesting potential for further invasion. Our results highlighted habitat contractions ranging from 41% (SSP245-2050) to 60% (SSP585-2070), associated with a shift in the centroid of suitable habitat towards the Atlantic coast. These contractions are particularly severe in Algeria, where suitable habitats could disappear by 2050, contrasting with stable habitats maintained in the Canary Islands under all scenarios. Urgent habitat restoration in Algeria is crucial, including efforts to combat poaching. In Morocco, targeted in situ conservation is recommended, while in the Canary Islands, the focus should be on invasive species management and public awareness campaigns to prevent further spread.