Delayed incubation leads to hatching failure of a Burrowing Owl

• Published in: The Wilson journal of ornithology Vol. 135; no. 3
• Main Authors: Lundblad, Carl G, Conway, Courtney J
• Format: Journal Article
• Language: English
• Published: Wilson Ornithological Society 01.09.2023
• Subjects: Owls; Weather; Oregon; North America
• ISSN: 1559-4491
• DOI: 10.1676/22-00089

Birds face strong selective pressures to complete individual nesting attempts as quickly as possible to minimize exposure of nests to predators and weather, maximize rcnesting potential, and maximize hatching success. As a result, the duration of developmental periods and of overall nest periods are often relatively constant within species. However, birds may sometimes be subject to acute energetic constraints that may preclude them from initiating incubation at the optimal time. We report an extraordinary case of delayed incubation by a female Burrowing Owl (Athene cunicularid) in Oregon, USA, which contrasted sharply with a large sample of nests monitored by motionactivated video cameras in western North America from 2015 to 2018. The focal female delayed incubation by 11 d following clutch completion and subsequently experienced near total hatching failure of her clutch. This observation corroborates previous experimental studies regarding the limits to egg viability and trade-offs between the timing of incubation onset and hatching success. These findings illustrate the acute trade-offs faced by nesting birds, and the cost of delayed incubation that we observed in this owl could help explain the cause of asynchronous hatching. Received 15 September 2022. Accepted 9 September 2023.