Developmental changes in serum androgen levels of Eastern Screech-Owls (Megascops asio)

Wilson Journal of Ornithology
By:  and 



We studied androgen production during development in nestling Eastern Screech-Owls (Megascops asio) and hypothesized that gender and hatch order might influence serum levels of testosterone and androstenedione. Testosterone levels were highest immediately after hatching and declined significantly in the 4 weeks leading to fledging. The average level of testosterone for 1-7 day-old owls was 3.99 - 0.68 ng/ml. At 22-28 days of age, the average testosterone level for nestling owls was 0.83 - 0.18 ng/ml. Testosterone levels did not differ between males or females. The average testosterone level for male nestlings was 2.23 - 0.29 ng/ml and 2.39 - 0.56 ng/ml for female nestlings. The average level of androstenedione for nestling owls was 1.92 - 0.11 ng/ml and levels remained constant throughout development. Levels were significantly higher in males than females. The average androstenedione level was 1.77 - 0.16 ng/ml for male nestlings and 1.05 - 0.24 ng/ml for female nestlings. Hatching order did not affect levels of either androgen. Our results provide a foundation for future studies of androgen production by nestling owls.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Developmental changes in serum androgen levels of Eastern Screech-Owls (Megascops asio)
Series title Wilson Journal of Ornithology
Volume 122
Issue 4
Year Published 2010
Language English
Publisher Wilson Ornithological Society
Publisher location Ann Arbor, MI
Contributing office(s) Patuxent Wildlife Research Center
Description 7 p.
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Wilson Journal of Ornithology
First page 755
Last page 761
Country United States