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Double-crested Cormorants

The double-crested cormorant (Phalacrocorax auritus) is a long-lived, colonial-nesting waterbird native to North America. One of 38 species of cormorants worldwide, and one of six species in North America, it is usually found in flocks, and is sometimes confused with geese or loons when on the water.

The U.S. Fish and Wildlife Service responsibilities include the conservation and management of double-crested cormorants, which are included on the list of protected migratory birds.

The U.S. Fish and Wildlife Service has statutory authority and responsibility for enforcing the Migratory Bird Treaty Act. Under the Migratory Bird Treaty Act, the U.S. Fish and Wildlife Service implements conventions between the United States and four neighboring countries (Canada, Mexico, Russia, and Japan) for the protection of our shared migratory birds, and maintains the list of species protected under the Migratory Bird Treaty Act.

The Western Population- East Sand Island, Lower Columbia River, Oregon

Since 1990, the growth of the double-crested cormorant western population has been primarily associated with the growth of the East Sand Island colony.  The nesting colony of double-crested cormorants on East Sand Island has increased nearly 100-fold since the colony was first recorded in 1989.  The colony at East Sand Island has remained relatively stable since 2004, averaging approximately 12,900 breeding pairs.  The largest breeding colony of double-crested cormorants in western North America, and likely all of North America, resides on East Sand Island.

Double-crested Cormorant Management Plan to Reduce Predation of Juvenile Salmonids in the Columbia River Estuary

In 2015, the U.S. Army Corps of Engineers (Corps) prepared a Final Environmental Impact Statement (FEIS) and management plan to reduce predation of juvenile salmon and steelhead by double-crested cormorants in the Columbia River Estuary.  The Corps chose to implement Alternative C-1, documented in their Record of Decision.  For more information please visit
http://www.nwp.usace.army.mil/environment/cormorants/

The U.S. Fish and Wildlife Service was a cooperating agency on the FEIS, providing technical expertise on Double-crested Cormorant monitoring and population model.  The U.S. Fish and Wildlife Service developed the population model to provide a science-based assessment of the effects of different levels of individual and egg take on the East Sand Island colony and the western population of double-crested cormorants. 

The U.S. Fish and Wildlife Service received an application for a Federal Migratory Bird Permit from the Corps after they signed their Record of Decision, for the take of adult cormorants and nests, so that they may implement Alternative C-1 in the FEIS.  We used the analyses in the FEIS to support our permit decision-making on this application, documented in our Record of Decision

U.S. Fish and Wildlife Service Record of Decision

The U.S. Fish and Wildlife Service issued a depredation permit valid in 2015 that  allowed the Corps of Engineers to implement the first of year of Double-crested Cormorant management on East Sand Island as applied for and described in Alternative C-1 of their FEIS; this decision is described in the U.S. Fish and Wildlife Service’s Record of Decision.  The permit authorized the take of 3,489 individual Double-crested Cormorants and 5,879 nests, and 105 Brandt’s and 10 Pelagic cormorants.   

Alternative C-1 of the FEIS describes a four-year strategy, to reduce the size of the breeding colony on East Sand Island from approximately 13,000 pairs to between 5,380 and 5,939 pairs, through culling of adults and egg oiling; non-lethal measures will be implemented to the extent practicable, followed by a habitat management phase to maintain the population at target levels.  The total planned take of adults is 10,912 individual Double-crested Cormorants (3,489, 3,114, 2,408, and 1,902 Double-crested Cormorants in years 1 to 4, respectively). In addition to culling individuals, approximately 46 percent of nests in years 1-3 would be oiled (15,184 nests oiled in total; 5,879, 5,247, and 4,058 in years 1-3).  Implementation will occur within a well-monitored and adaptive management framework and requested take levels may be adjusted within that framework to ensure objectives, including not threatening the western population of Double-crested Cormorants, are met.  Depredation permits have a tenure of up to one year, thus the Corps plans to submit a depredation permit application annually for the duration of their management plan.  The Service will evaluate each application upon submittal for fulfillment of all regulatory requirements.

Year 2

The Corps submitted a depredation permit renewal request for the take associated with the second year of management.  The Service evaluated the renewal request and has decided to issue the depredation permit valid through January 31, 2017.  The Service evaluated the request ensuring that the proposed action fulfilled regulatory requirements including whether or not  the western population of Double-crested Cormorants would be threatened.  The permit authorizes the take of 3,114 individual Double-crested Cormorants and 5,247 nests, and 93 Brandt’s and 9 Pelagic cormorants.

Year 3


The Corps submitted a depredation permit renewal request for the take associated with the third year of management.  The Service evaluated the renewal request and has decided to issue the depredation permit valid through January 31, 2018.  The Service evaluated the request ensuring that the proposed action fulfilled regulatory requirements and does not threaten the Western Population of Double-crested Cormorants.  The permit authorizes the take of 2,408 individual Double-crested Cormorants and 4,058 nests, and 72 Brandt’s and 7 Pelagic cormorants.

Monitoring the Western Population


The Pacific Flyway Monitoring Strategy calls for west-wide monitoring of double-crested cormorants to be implemented every 3 years, 4 times from 2014 to 2024. To minimize impacts to the western population of double-crested cormorant, the Corps will follow the protocol outlined in the Pacific Flyway Council Monitoring Strategy.  Each year under Phase I, the Corps will monitor all specified locations of the monitoring strategy, where and when there are not already established monitoring efforts and secure funding sources, supplement data processing of aerial photography, and assist in preparing an annual summary report of the Pacific Flyway Council and other collected monitoring data.
The objective of this monitoring strategy is to detect a 5 percent annual change in the number of breeding pairs in the western population of DCCOs.  Monitoring will be used to evaluate and adjust future management activities which will allow time for annual evaluation, adaptive management changes, and increases the ability for the western population to respond from a potential catastrophic event.

Frequently Asked Questions

Double-crested Cormorant Western Population Status Evaluation - 2018 Annual Report

Last Updated: October 18, 2019
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