Morphological variation and sexual dimorphism of the common leopard (Panthera pardus) in the Middle East and their implications for species taxonomy and conservation

Designation of subspecies in wild cats (Carnivora: Felidae) often results from arbitrary description of morphological characters and it can be confounded by geographic variation and sexual dimorphism. To test the contribution of these factors to subspecies grouping, I studied 22 cranial shape variables in 55 skulls of the common leopard (Panthera pardus) from the Middle East and estimated their differences between the three subspecies groups in this region, namely the Persian leopard (P.p. ciscaucasica Satunin, 1914), Anatolian leopard (P.p. tulliana Valenciennes, 1856) and Arabian leopard (P.p. nimr Hemprich et Ehrenberg, 1833), among sexes. Male and female skulls increased in size with latitude (Bergmann's rule) and female skull size also significantly increased with longitude. Results suggest that taxonomic grouping was determined only by female skulls which showed high variation between the groups, unlike male skulls which varied more within the groups. Inter-group variation of female skulls, presence of only four cranial variables which are significantly different between the groups in all skulls, and the lack of historical barriers for subspeciation may suggest the existence of one leopard subspecies in the Middle East. Independent genetic and ecological studies are required to settle this taxonomic issue. This study urges for securing connectivity between the two remnant, taxonomically identical populations in the region, namely in (i) Iran and neighbouring countries and (ii) four Arab countries and Israel, with more research and conservation efforts in these populations and in the Fertile Crescent lying between them.