ScholarsArchive@OSU

Citeable URL: http://ir.library.oregonstate.edu/concern/articles/sq87bw10c

To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The article was published by John Wiley & Sons Ltd. and is in the public domain. The published article can be found at:  http://onlinelibrary.wiley.com/journal/10.1002/%28ISSN%291937-2817.

Descriptions

Attribute Name	Values
Creator	Courtot, Karen N. Carter, Harry R. Shuford, W. David Adkins, Jessica Y. Collis, Ken Lyons, Donald E. Capitolo, Phillip J. Roby, Daniel D.
Abstract or Summary	The status of the double-crested cormorant (Phalacrocorax auritus) in western North America was last evaluated during 1987–2003. In the interim, concern has grown over the potential impact of predation by double-crested cormorants on juvenile salmonids (Oncorhynchus spp.), particularly in the Columbia Basin and along the Pacific coast where some salmonids are listed for protection under the United States Endangered Species Act. Recent re-evaluations of double-crested cormorant management at the local, flyway, and federal level warrant further examination of the current population size and trends in western North America. We collected colony size data for the western population (British Columbia, Washington, Oregon, Idaho, California, Nevada, Utah, Arizona, and the portions of Montana, Wyoming, Colorado and New Mexico west of the Continental Divide) by conducting aircraft-, boat-, or ground-based surveys and by cooperating with government agencies, universities, and non-profit organizations. In 2009, we estimated approximately 31,200 breeding pairs in the western population. We estimated that cormorant numbers in the Pacific Region (British Columbia, Washington, Oregon, and California) increased 72% from 1987–1992 to circa 2009. Based on the best available data for this period, the average annual growth rate (λ) of the number of breeding birds in the Pacific Region was 1.03, versus 1.07 for the population east of the Continental Divide during recent decades. Most of the increase in the Pacific Region can be attributed to an increase in the size of the nesting colony on East Sand Island in the Columbia River estuary, which accounts for about 39% of all breeding pairs in the western population and is the largest known breeding colony for the species (12,087 breeding pairs estimated in 2009). In contrast, numbers of breeding pairs estimated in coastal British Columbia and Washington have declined by approximately 66% during this same period. Disturbance at breeding colonies by bald eagles (Haliaeetus leucocephalus) and humans are likely limiting factors on the growth of the western population at present. Because of differences in biology and management, the western population of double-crested cormorants warrants consideration as a separate management unit from the population east of the Continental Divide.
Resource Type	Article
DOI	10.1002/jwmg.737
Date Available	2014-11-03T21:28:40+00:00
Date Issued	2014-09
Citation	Adkins, J. Y., Roby, D. D., Lyons, D. E., Courtot, K. N., Collis, K., Carter, H. R., Shuford, W. D., & Capitolo, P. J. (2014). Recent population size, trends, and limiting factors for the double-crested cormorant in western North America. Journal of Wildlife Management, 78(7), 1131–1142. doi:10.1002/jwmg.737
Series	Journal of Wildlife Management Vol. 78 no. 7
Keyword	Status assessment Pacific coast Population Limiting factors Phalacrocorax auritus Cormorant
Rights Statement	Copyright Not Evaluated
Funding Statement (additional comments about funding)	Funding was provided by the U.S. Army Corps of Engineers, Portland District, Portland, Oregon (Geoff Dorsey and Paul Schmidt).
Publisher	John Wiley & Sons Ltd.
Peer Reviewed	Yes
Language	English [eng]
Replaces	http://hdl.handle.net/1957/53593
Additional Information	description.provenance : Submitted by Erin Clark (erin.clark@oregonstate.edu) on 2014-11-03T21:28:23Z No. of bitstreams: 1 AdkinsJessicaFisheriesWildlifeRecentPopulationSize.pdf: 619309 bytes, checksum: b582f7a1fc04707770b4689c4b1c27b0 (MD5) description.provenance : Made available in DSpace on 2014-11-03T21:28:40Z (GMT). No. of bitstreams: 1 AdkinsJessicaFisheriesWildlifeRecentPopulationSize.pdf: 619309 bytes, checksum: b582f7a1fc04707770b4689c4b1c27b0 (MD5) Previous issue date: 2014-09 description.provenance : Approved for entry into archive by Erin Clark(erin.clark@oregonstate.edu) on 2014-11-03T21:28:40Z (GMT) No. of bitstreams: 1 AdkinsJessicaFisheriesWildlifeRecentPopulationSize.pdf: 619309 bytes, checksum: b582f7a1fc04707770b4689c4b1c27b0 (MD5)

Relationships

Parents:

This work has no parents.

Last modified

Items

Thumbnail	Title	Date Uploaded	Visibility	Actions
	AdkinsJessicaFisheriesWildlifeRecentPopulationSize.pdf	2017-07-27	Public	Press to Select an action Download