USE OF DNA ANALYSIS TO IDENTIFY SEX OF NORTHERN SPOTTED OWLS (STRIX OCCIDENTALIS CAURINA)

The spotted owl (Strix occidentalis) is a monochromatic species with s light sexual size dimorphism in adults. Methods currently available to identify sex of adult owls are ineffective for juveniles. Blood sampl es taken from owls from the eastern Cascade Mountains, Washington were used for cDNA cloning of a Z- and W-linked gene, DZWM1, to identify t he sex of adult owls of known sex. A blind assessment resulted in the correct identification of sex for all 59 owls sampled (45 subadult/adu lt and 14 juveniles recaptured as subadult/adult). We believe this tec hnique can be used to identify the sex of owls that cannot otherwise b e identified using less invasive morphometric methods. Both field and laboratory procedures are described.