Tag: Phalacrocorax auritus

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 […]

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 […]

Double-crested Cormorant Nesting in South Carolina

Double-crested Cormorant (Phalacrocorax auritus) Science Article 13 abstract For many years the Double-crested Cormorant (Phalacrocorax auritus) has been suspectedof nesting in South Carolina. Wayne (Birds of South Carolina, 1910, p. 12) saw Double-crested Cormorants on the coast during the summer, and he believed that they bred, WILLIAM POST and COLIN A. POST, The Chat Vol. […]

Heat increment of feeding in double-crested cormorants (Phalacrocorax auritus) andits potential for thermal substitution

Double-crested Cormorant (Phalacrocorax auritus) Science Article 3 abstract Diving endotherms inhabiting polar regions face potentially high thermoregulatory costs. Unless properly insulated, these animals will lose vast amounts of heat when diving in cold water, which has to be balanced by heat production. Heat generated as a by-product of digestion (heat increment of feeding, HIF) or […]

A test of an osteologically based age determination technique in the DoublecrestedCormorant Phalacrocorax auritus

Double-crested Cormorant (Phalacrocorax auritus) Science Article 15 abstract The ability to determine the age of birds accurately from their skeletons would be useful not only for population biology and wildlife management research but for avian palaeontological and archaeological analyses as well. While accurate osteologically based age determination techniques are available for some amphibians and reptiles […]

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 […]