The status of a rare phylogeographic lineage of the Vulnerable European souslik Spermophilus citellus, endemic to central Macedonia

Abstract

The conversion of grasslands for agriculture has triggered a serious decline of the European ground squirrel or souslik Spermophilus citellus, categorized as Vulnerable on the IUCN Red List since 1996. The Jakupica phylogeographic lineage of central Macedonia is the smallest of the three major evolutionary lines of the European souslik. This lineage is an important reservoir of within-species diversity and should be regarded as an independent unit for conservation management purposes. It is endemic to Mount Jakupica, where it lives in mountain pastures at 1,500-2,250 m altitude. The total area occupied by sousliks (884 ha) is fragmented and 94% of individuals occur in four colonies. Densities (0.8-5.5 adults ha-1) are lower than those reported elsewhere for the species, with the total population probably <2,000 adults. One large colony, reportedly of c. 1,000 sousliks, was decimated in 2007 by a catastrophic fire and had still not recovered by 2010. A steady decline in livestock grazing, together with the predicted advance of the tree line as a consequence of climate change, will probably reduce the optimal habitat for the souslik and negatively affect population fitness. Monitoring needs to be implemented, at least for the largest colonies, to provide early warning of any declines. © 2012 Fauna & Flora International.