THREE SIBLING SPECIES OF <i>ALECTORIS</i> PARTRIDGE

It is concluded that at least one of the two Balkan species has recently reached Thrace, and that at present altitudinal and possibly slight morphological and behavioural differences act as sufficient isolating mechanisms to prevent hybridization.

Abstract

SUMMARY In southeast Europe, two populations of Alectoris partridge meet. These differ sharply in several minor qualitative characters with no evidence of introgression. Morphological, ecological, and behavioural differences suggest that these are separate species, A. graeca and A. chukar. Clinal geographic variation of colour in the eastern Mediterranean within these two species appears to be correlated with climatic factors. The tendencies toward longer bills in southern mainland and island populations may constitute adaptations to drier and insular environments. Habitat preferences, diet, reproduction, and altitudinal distribution of these two forms are discussed and, where possible, contrasted. An additional, but less well documented example of sympatric Alectoris species is found in western China. Display in Alectoris partridge tends to emphasize the morphological patterns which are useful in taxonomy. Species characters may likewise function as warning stimuli and therefore tend to prevent mixed flocks. It is concluded that at least one of the two Balkan species has recently reached Thrace, and that at present altitudinal and possibly slight morphological and behavioural differences act as sufficient isolating mechanisms to prevent hybridization.