We studied plumage patterns of known-sex nestling and juvenile Short-eared Owls (Asio flammeus) to develop a sexing technique for nestlings in the field. Markings on the secondaries varied according to sex, and differences were apparent from about 10–15 days of age. We also provide aging formulas based on mass for nestlings up to 15 days of age and on wing length for nestlings older than that age. Finally, we evaluate growth parameters according to sex. The asymptotes of body mass, wing length, and tarsus length growth curves were higher in females than males. The inflexion point was attained earlier by males than by females.
How to translate text using browser tools
1 February 2000
SEX AND AGE DETERMINATION OF SHORT- EARED OWL NESTLINGS
Beatriz E. Arroyo,
Thomas DeCornulier,
Vincent Bretagnolle
ACCESS THE FULL ARTICLE
The Condor
Vol. 102 • No. 1
February 2000
Vol. 102 • No. 1
February 2000
aging techniques
Asio flammeus
growth parameters
sexing technique
short-eared owl