Life history traits (averages) Female sexual maturity 730 days Male sexual maturity 730 days Incubation 24 days Clutch size They orange-yellow area around the bill is very distinctive. Double-crested cormorant Lifespan, ageing, and relevant traits Maximum longevity 22.5 years (wild) Source ref. For these reasons the species is evaluated as Least Concern. The latest esti- mates for the Xorth American breeding pop- The Double-crested Cormorant is the most numerous and most widely distributed species of the 6 North American cormorants. The timing of breeding in Double-crested Cormorants (Phalacrocorax auritus albociliatus): Its effects on clutch size, nestling growth, diet and survival [dissertation]. Population.-Population size or density alone are poor indicators of pest status. Their bill is thin and serrated. APPEARANCE: The mostly dark cormorant has orange and white markings on the face and bright blue eyes. They nest on coastal cliffs and forage in rocky water, rarely traveling far from shore despite their name. They have a coral-red throat patch and neat white patches on the flanks. This race is the largest. Population of Double-crested Cormorants within the Pacific Flyway (PFC 2013). Vancouver, BC: University of British Columbia. Both parents incubate the pale blue-green eggs for a one-month duration. Keywords: cormorant, double-crested cormorant, fish For example, the Double-crested Cormorant population in the Great Lakes is now estimat- ed at approximately 27,000 pairs in an area of 244,000 krn? Thus, although the impact of cormorants on the perch population may vary slightly from year to year, we conclude that cormorant predation had minimal impact on the local perch population. Maximum longevity from banding studies was 22.5 years . The Double-crested Cormorant is widely distributed across North American. Research on the nesting of the Double-crested Cormorant (Phalacrocorax auritus auritus) was undertaken to determine the nesting ecology of the bird on Utah Lake, Utah County, and the possible effects that diking Provo Bay would have on the cormorants breeding there. Here we provide you with detailed information about Double crested Cormorant. Smithsonian Institute Press, Washington, D.C. xiv + 445 pp. Double-crested Cormorant (Phalacrocorax auritus). Double-Crested Cormorant Contaminant Exposure Data . This … Concentrations in Adults, Juveniles, and Nestlings. The Birds of North America Online (A. Poole, Ed.). cincinatus is found in Aleutian Islands (E from Unalaska) to Alexander Archipelago in SE Alaska. mortality of legal-size perch (≥178 mm), whereas summer sport fishing accounted for 2.5 percent. Species Account Number 441. The population size is extremely large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure).