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Dorr et al. 2016 DCCO Repro. Characteristics Waterbirds.pdf
Waterbirds (2016)
  • Brian S Dorr
  • Katie C Hanson-Dorr
  • Scott C. Barras
  • Travis L DeVault, USDA National Wildlife Research Center
Double-crested Cormorants (Phalacrocorax auritus) are intensely managed through culling in North America to reduce presumed damage to commercial and natural resources. To evaluate this management, there is a critical need to understand the reproductive biology of Double-crested Cormorants. Gonadal development, reproductive potential and breeding status were determined by necropsy for 1,781 Double-crested Cormorants salvaged each month of the year from control programs in their wintering and breeding ranges in seven States in the USA. Gonadal development of males peaked earlier in the year than females. Mean and maximum reproduc- tive potential was five and 13 ovum, respectively. The average proportion of non-breeding female Double-crested Cormorants culled from breeding colonies was 14.9% (n = 202) and from foraging flocks on the breeding grounds was 22.1% (n = 358). This demographic information should be considered when evaluating and modeling effects of Double-crested Cormorant management in North America.
  • breeding status,
  • culling,
  • Double-crested Cormorant,
  • management,
  • nesting colony,
  • Phalacrocorax
Publication Date
Spring March, 2016
Citation Information
Brian S Dorr, Katie C Hanson-Dorr, Scott C. Barras and Travis L DeVault. "Dorr et al. 2016 DCCO Repro. Characteristics Waterbirds.pdf" Waterbirds Vol. 39 Iss. 1 (2016) p. 81 - 85
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