MEASUREMENTS OF WINTERING DOUBLE-CRESTED CORMORANTS AND DISCRIMINANT MODELS OF SEX

Body mass, maximum wing length, culmen length, culmen depth, tarsal length and sex were recorded from 200 Double-crested Cormorants (Phalacrocorax auritus auritus) collected from January through April 1991 at roost sites in the delta region of Mississippi. Body mass and tarsal length appeared to distinguish this population as excluding the Ii a. floridanus subspecies, which is also reported to be geographically restricted to the Gulf Coast, or at least 250 km south of our study area Wing length, culmen depth and culmen length, in order of importance, were the most useful variables for identifying sex in a discriminant function model that predicted sex with 96.5% accuracy.