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 sympatric in north-eastern Spain. Seven enzyme systems (alcohol dehydrogenase, esterase, glutamate dehydrogenase, glucose-6-phosphate dehydrogenase, leucin aminopeptidase, L-lactate dehydrogenase and superoxide dismutase) were analyzed, resolving 22 presumed genetic loci with 28 alleles; 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 the whole, the results demonstrate that these Sturnus populations share a gene pool, showing slight genetic differences between the two starling speices.