Sex Determination Of The Bald Eagle By RadioImmunoassay Of 17B-Estradiol And Testosterone

Abstract

In order to develop a sex-determined difference in sex steroid levels in bald eagles (Haliaeetus leucocephalus). whole blood samples, obtained by McClelland and coworkers (1982) in Glacier National Park, Montana, were analyzed for 17j3-estradiol and testosterone levels. Samples from 14 bald eagles, 7 males and 7 females, were analyzed for 17J3-estradiol by radioimmunoassay (RIA). No significant levels of this steroid were found. Fourteen bald eagle whole blood samples, taken from 7 males and 7 females, were analyzed for testosterone levels by RIA. Significant levels of this hormone were found in four samples, two taken from males. The testosterone levels found in the two male samples were markedly higher than the levels found in the female samples. Also, testosterone levels in male samples assayed seemed to increase with the age of the eagle. The data obtained from the eagle samples containing testosterone seems to indicate that sex determination is possible by RIA.