Egg-laying increases body temperature to an annual maximum in a wild bird

• Published in: Scientific reports Vol. 12; no. 1; p. 1681
• Main Authors: Guillemette, Magella, Pelletier, David
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 31.01.2022; Nature Publishing Group; Nature Portfolio
• Subjects: 631/158/2455; 631/443/319; Animals; Animals, Wild - metabolism; Animals, Wild - physiology; Aquatic birds; Biological Evolution; Birds; Body temperature; Body Temperature Regulation; Ducks - metabolism; Ducks - physiology; Egg laying; Female; Heart Rate; Heat tolerance; Heat waves; High temperature; Hormones - metabolism; Humanities and Social Sciences; multidisciplinary; Oviposition; Predation; Reptiles; Science; Science (multidisciplinary); Time Factors
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-022-05516-0

Most birds, unlike reptiles, lay eggs successively to form a full clutch. During egg-laying, birds are highly secretive and prone to disturbance and predation. Using multisensor data loggers, we show that average daily body temperature during egg-laying is significantly increased (1 °C) in wild eider ducks ( Somateria mollissima ). Strikingly, this increase corresponds to the annual maximum body temperature (40.7 °C), representing a severe annual thermogenic challenge. This egg-laying-induced rise in body temperature may prove to be a common feature of wild birds and could be caused by habitat-related thermoregulatory adjustments and hormonal modulation of reproduction. We conclude our findings with new perspectives of the benefits of high body temperature associated with egg-laying of birds and the potential effect of heat stress that may occur with the future advent of heatwaves.