Testosterone and prolactin levels in incubating Mountain Plovers (Charadrius montanus)

Abstract

The hormones prolactin (PRL) and testosterone (T) are linked to breeding behaviors such as territory defense, incubation, and brood-rearing in birds. The Mountain Plover (Charadrius montanus) is a shorebird with an uncommon parental care system in which males and females tend separate nests. We collected blood from incubating male (n = 38) and female (n = 33) Mountain Plovers in Montana to determine how circulating plasma PRL and T varied by sex, day of incubation, and across the nesting season. PRL levels were similar in males and females. There was no relationship between day of incubation or Julian day and circulating PRL for either sex. T concentrations were higher in males than in females and tended to decrease across the incubation season for both sexes. BioOne (www.bioone.org) is a nonprofit, online aggregation of core research in the biological, ecological, and environmental sciences. BioOne provides a sustainable online platform for over 170 journals and books published by nonprofit societies, associations, museums, institutions, and presses.Your use of this PDF, the BioOne Web site, and all posted and associated content indicates your acceptance of BioOne's Terms of Use, available at www.bioone.org/page/ terms_of_use.Usage of BioOne content is strictly limited to personal, educational, and non-commercial use. Commercial inquiries or rights and permissions requests should be directed to the individual publisher as copyright holder. ABSTRACT.-The hormones prolactin (PRL) and testosterone (T) are linked to breeding behaviors such as territory defense, incubation, and brood-rearing in birds. The Mountain Plover (Charadrius montanus) is a shorebird with an uncommon parental care system in which males and females tend separate nests. We collected blood from incubating male (n ¼ 38) and female (n ¼ 33) Mountain Plovers in Montana to determine how circulating plasma PRL and T varied by sex, day of incubation, and across the nesting season. PRL levels were similar in males and females. There was no relationship between day of incubation or Julian day and circulating PRL for either sex. T concentrations were higher in males than in females and tended to decrease across the incubation season for both sexes.