Tag: Double-crested Cormorant

Conservation Implications of the Large Colony of Double-crested Cormorants on East Sand Island, Columbia River Estuary, Oregon, U.S.A.

Double-crested Cormorant (Phalacrocorax auritus) Science Article 10 abstract The breeding colony of the Double-crested Cormorant (Phalacrocorax auritus) on East Sand Island in the Columbia River estuary has grown dramatically over the last 13 years, in contrast to declines at other colonies along the coast of the Pacific Northwest. Immigration from other colonies has occurred and […]

Prey fish consumption by Double-crested Cormorants in western Lake Erie near WestSister Island, Ohio

Double-crested Cormorant (Phalacrocorax auritus) Science Article 18 abstract The objectives for this study were to: 1) determine the diet of Double-crested Cormorants (Phalacrocorax auritus, hereafter: cormorants) in western Lake Erie; 2) to determine if yellow perch (Perca flavescens) or walleye (Sander vitreus) were a noteworthy prey item; and 3) to determine if the invasive round […]

Foraging patterns of male and female DoublecrestedCormorants nesting in the Columbia Riverestuary

Double-crested Cormorant (Phalacrocorax auritus) Science Article 17 abstract The nesting colony of Double-crested Cormorants, Phalacrocorax auritus (Lesson, 1831), on East Sand Island in the Columbia River estuary is currently the largest for this species on the Pacific Coast of North America. We used radiotelemetry to investigate the spatial and temporal foraging patterns of nesting cormorants […]

Observations of Nocturnal Foraging in the Double-crested Cormorant

Double-crested Cormorant (Phalacrocorax auritus) Science Article 16 abstract Double-crested Cormorants (Phalacmcorax avril us) are normally considered a diurnal species. Herewe describe cormorants foraging nocturnally in an oxbow lake in Mississippi. We have observed this behavior onlyonce during 30 capture attempts over seven years. D. Tommy King, J. Brent Harrf, Brian Dorr and David Reinhoid, Colonial […]


Double-crested Cormorant (Phalacrocorax auritus) Science Article 9 abstract Kleptoparasitism, or the stealing of resources, has been observed within and betweenmany bird species (Brockmann and Barnard 1979, Furness and Monaghan 1987).Although the kleptoparasite sometimes steals food without aggression towards the host,the host may be threatened or even attacked (Brockmann and Barnard 1979). In thisnote, I report […]

Double-Crested Cormorant Predation on Smallmouth Bass and Other Fishesof the Eastern Basin of Lake Ontario

Double-crested Cormorant (Phalacrocorax auritus) Science Article 12 abstract During the summer of 1998, the New York State Department of Environmental Conservation (NYSDEC) and the United States Geological Survey (USGS) conducted 11 studies designed to evaluate the impact of double-crested cormorant predation on smallmouth bass and other fish populations in the New York waters of the […]

Historic Populations of the Double-crested Cormorant(Phalacrocorax auritus): Implications for Conservationand Management in the 21stCentury

Double-crested Cormorant (Phalacrocorax auritus) Science Article 8 abstract In North America, the Double-crested Cormorant (Phalacrocorax auritus) is currently abundant, widely distributed across five broad geographic regions, and often perceived as overabundant. In many U.S. states and Canadian provinces, policy makers are pressured to significantly reduce cormorant numbers, primarily to minimize conflicts between cormorants and fish […]

Bacterial flora of free-living Double-crested cormorant (Phalacrocorax auritus) chicks onPrince Edward Island, Canada, with reference to enteric bacteria and antibiotic resistance

Double-crested Cormorant (Phalacrocorax auritus) Science Article 7 abstract Cloacal and pharyngeal swabs from 100 tree-nesting Double-crested cormorant (DCC) chickswere examined by culture for commensal and potentially pathogenic bacteria. No Salmonella or Erysipelothrix were isolated from the cloacal swabs. Twenty-two cloacal swabs were positive for Campylobacter, of which 14 were C. jejuni, C. coli, and 1 […]


Double-crested Cormorant (Phalacrocorax auritus) Science Article 6 abstract Outbreaks of morbidity and mortality in double-crested cormorants (Phalacrocorax auritus) along Florida’s Gulf Coast have occurred sporadically for at least 30 yr. During these outbreaks, the Clinic for the Rehabilitation of Wildlife, located on Sanibel Island in Florida, has admitted a substantial number of cormorants with consistent […]

Impact of Double-crested Cormorant Depredationon the U.S. Farm-Raised Catfish Industry

Double-crested Cormorant (Phalacrocorax auritus) Science Article 11 abstract Much is made of the many non-market values contributed by wildlife and the many forms of wildlife dependent recreation. However, sometimes lost in the discussion of wildlife values and the importance of wildlife are the market and non-market costs resulting from wildlife damages to human enterprises. Often […]