Cooper's Hawks (Accipiter cooperii) typically lay 3–5 eggs per clutch, rarely 6 eggs, and there are 2 accounts of 7-egg clutches and 1 record of a maximum 8-egg clutch for the species. Brood sizes of 3–5 young are common and the previous maximum brood count is 6 young. However, in 2019, we found an urban nest in Stevens Point, Wisconsin, with 7 eggs that resulted in a record high of 7 fledglings. We genetically confirmed that the attending male sired all the offspring and the attending female laid all 7 eggs. Larger body size of the tending adults may have been a factor in the exceptional reproduction reported here.
|Publication Subtype||Journal Article|
|Title||Record fledging count from a seven-egg clutch in the Cooper’s Hawk (Accipiter cooperii)|
|Series title||Wilson Journal of Ornithology|
|Contributing office(s)||Alaska Science Center Biology WTEB|
|Google Analytic Metrics||Metrics page|