Record fledging count from a seven-egg clutch in the Cooper’s Hawk (Accipiter cooperii)

Robert N. Rosenfield; Sarah A. Sonsthagen; Ann Elizabeth Riddle-Berntsen; Evan Kuhel

doi:10.1676/1559-4491-132.2.460

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Record fledging count from a seven-egg clutch in the Cooper’s Hawk (Accipiter cooperii)

Robert N. Rosenfield·Sarah A. Sonsthagen·Ann Elizabeth Riddle-Berntsen·Evan Kuhel

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Abstract

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.

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Wilson Journal of Ornithology Article

Source-reported bounding extent: 44.46613109099745° to 44.593401045429374° latitude; -89.65427398681639° to -89.46338653564453° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

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Robert N. Rosenfield, Sarah A. Sonsthagen, Ann Elizabeth Riddle-Berntsen, Evan Kuhel. 2021. Record fledging count from a seven-egg clutch in the Cooper’s Hawk (Accipiter cooperii). https://doi.org/10.1676/1559-4491-132.2.460

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