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Double-crested Cormorant

Cormorants in a tree
Cormorants in a tree.

Cormorant Management in New York

Cormorant populations have increased markedly across New York in recent years. This is likely a result of a cleaner environment and fewer pesticides causing reproductive problems. Large nesting colonies are a sight to behold, but high densities of nesting cormorants are not without problems. In Lake Champlain, destruction of vegetation on nesting islands in Vermont by cormorants threatens populations of common terns, a threatened species. On Oneida Lake, cormorant occupation of islands also threatens survival of the common tern. In addition, thousands of cormorants stopping over during the fall migration have raised concerns about their effect on ecologically and economically important fisheries. And in the eastern basin of Lake Ontario, cormorants have been found to be a significant predator of smallmouth bass, which is a native, economically important species.

The Department's mission includes a responsibility to manage fish and wildlife resources for the benefit of current and future generations. It is not an easy job. It often requires balancing of competing interests to find the course of action that will do the most good with the least harm. The profession of wildlife management has grown in sophistication in considering the human side of the equation. We also pay attention to social and economic issues and consider people's values and desires in developing our management plans. We are currently involved in a series of cormorant studies and management activities with our counterparts in other states, universities, the federal government, and Canada. Sound science is at the base of our investigations. It requires that we keep an open mind, document our observations, and learn from experience.

Management of Double-Crested Cormorants to Protect Public Resources

The Division of Fish and Wildlife (DFW), in cooperation with U.S. Department of Agriculture (USDA) Wildlife Services, carries out integrated double-crested cormorant (Phalacrocorax auritis) management programs to alleviate and prevent conflicts with public resources at specific problem areas in New York. Cormorant populations have increased in abundance to the point where they are impacting other colonial-nesting waterbird species and economically important recreational fisheries in some areas of New York. Population control efforts during the past 10 years have helped reduce these conflicts, but continued action is needed.

DFW manages cormorants in four areas of New York (eastern Lake Ontario, Oneida Lake, Buffalo Harbor/Niagara River, and Lake Champlain/eastern Adirondacks). Actions include:

  • egg-oiling and nest destruction
  • non-lethal deterrents to nesting
  • habitat modification
  • exclusion techniques
  • spring and fall hazing on Oneida Lake and other nearby lakes and;
  • limited lethal take of up to 700 birds statewide to complement and increase effectiveness of other measures.

For the most part, this is a continuation of measures used in the past, except that DFW may increase use of lethal control measures (i.e., shooting or live-trapping and euthanizing birds) in some situations. Lethal removal of up to 800 cormorants statewide will have a negligible impact on the total population in New York (1.9% of 43,000 birds) or upstate only (2.9% of 28,000 birds).


More about Double-crested Cormorant:

  • Impact of Double-crested Cormorant Predation 1998 - Table of Contents for the 1998 report: Impact of Double-Crested Cormorant Predation on the Smallmouth Bass and Other Fishes of the Eastern Basin of Lake Ontario; a cooperative report prepared by: New York State Department of Environmental Conservation, Bureau of Fisheries and United States Geological Survey, Biological Resources Division.
  • Impact of Double-crested Cormorant Predation 1999 - Table of Contents for the 1999 report: Impact of Double-Crested Cormorant Predation on the Smallmouth Bass and Other Fishes of the Eastern Basin of Lake Ontario; a cooperative report prepared by: New York State Department of Environmental Conservation, Bureau of Fisheries and United States Geological Survey, Biological Resources Division.
  • Impact of Double-crested Cormorant Predation 2000 - Table of Contents for the 2000 report: Impact of Double-Crested Cormorant Predation on the Smallmouth Bass and Other Fishes of the Eastern Basin of Lake Ontario; a cooperative report prepared by: New York State Department of Environmental Conservation, Bureau of Fisheries and United States Geological Survey, Biological Resources Division.
  • Impact of Double-crested Cormorant Predation 2001 - Table of Contents for the 2001 report: Impact of Double-Crested Cormorant Predation on the Smallmouth Bass and Other Fishes of the Eastern Basin of Lake Ontario; a cooperative report prepared by: New York State Department of Environmental Conservation, Bureau of Fisheries and United States Geological Survey, Biological Resources Division.
  • Impact of Double-crested Cormorant Predation 2002 - Table of Contents for the 2002 report: Impact of Double-Crested Cormorant Predation on the Smallmouth Bass and Other Fishes of the Eastern Basin of Lake Ontario; a cooperative report prepared by: New York State Department of Environmental Conservation, Bureau of Fisheries and United States Geological Survey, Biological Resources Division.
  • Impact of Double-crested Cormorant Predation 2003 - Table of Contents for the 2003 report: Impact of Double-Crested Cormorant Predation on the Smallmouth Bass and Other Fishes of the Eastern Basin of Lake Ontario; a cooperative report prepared by: New York State Department of Environmental Conservation, Bureau of Fisheries and United States Geological Survey, Biological Resources Division