ALLOZYME POLYMORPHISM AND INTERSPECIFIC RELATIONSHIPS IN THE COMMON STARLING (STURNUS-VULGARIS) AND SPOTLESS STARLING (S-UNICOLOR) (AVES, STURNIDAE)

This paper reports a genetic study of Sturnus vulgaris and S. unicolor (Sturnidae), two similar bird species which have recently become symp atric in north-eastern Spain. Seven enzyme systems (alcohol denydrogen ase, esterase, glutamate dehydrogenase, glucose-6-phosphate dehydrogen ase, leucin aminopeptidase, L-lactate dehydrogenase and superoxide dis mutase) were analyzed, resolving 22 presumed genetic loci with 28 alle les; 27 of them were found in both species. Gene flow was estimated to be number of migrants per generation (Nm) = 6, and genetic identities among populations were high, ranging from I = 0.96 to I = 0.99. On th e whole, the results demonstrate that these Sturnus populations share a gene pool, showing slight genetic differences between the two starli ng species.