Nowhere left to go: the Sinai Hairstreak Satyrium jebelia

Abstract

High-mountain endemics with very restricted ranges are likely to have a high risk of extinction under the various scenarios of global warming. Endemic to the high mountains of the St Katherine Protectorate in South Sinai (Egypt), the Sinai Hairstreak Satyrium jebelia is just such a species. For the first time, its population size was estimated and its distribution and that of its larval food plant (Rhamnus dispermus) were mapped. The total world population in 2012 was estimated to be 1,010 individuals, perhaps divided into six smaller sub-populations of varying size. Its moderate dispersal ability and the relatively close proximity of the sub-populations may indicate metapopulation structure, but more data are needed. Aspects of host-plant and habitat quality were significant predictors of the presence of Sinai Hairstreaks on individual trees. No immediate threats are evident except global warming: if current climate-change predictions for Egypt are correct, the quality of habitat and plant diversity will decrease in the St Katherine Protectorate, with obvious long-term conservation implications.