Is sex-specific mass gain in Cory's shearwater Calonectris diomedea related to begging and steroid hormone expression?

Quillfeldt, P., Trager, I., Griffiths, K., Buchanan, K. and Masello, J. (2006) Is sex-specific mass gain in Cory's shearwater Calonectris diomedea related to begging and steroid hormone expression? Behavioral Ecology and Sociobiology, 61(5), pp. 793-800.

Abstract

Mass differences between the sexes of dimorphic bird species often appear early in the nestling development. But how do adults know how much to feed a chick in a sexually dimorphic species? Do chicks of the heavier sex beg more? We studied begging in Cory’s shearwaters Calonectris diomedea, a species with heavier adult and juvenile males than females. We found that begging rates and call numbers were not different between male and female chicks, but parameters of begging intensity differed between the sexes in their relationship to chick body condition. For the same body condition, males had significantly higher begging call numbers and rates. Acoustical parameters, which were analysed semi-automatically, included the lengths of call and silence intervals, the minimum, mean and maximum frequency in a call and the number of frequency peaks within a call. We found no consistent differences of acoustic begging call elements between the sexes. Male and female chicks did not differ in the levels of the steroid hormones testosterone or corticosterone in the second quarter of the nestling period, and the mechanism leading to sex-related differences in begging rates for a given body condition remains unknown.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Griffiths, Mrs Kate
• Authors: Quillfeldt, P., Trager, I., Griffiths, K., Buchanan, K., and Masello, J.
• Subjects: Q Science > QH Natural history > QH301 Biology
• College/School: College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Journal Name: Behavioral Ecology and Sociobiology
• ISSN: 0340-5443
• ISSN (Online): 1432-0762