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Recurring waterbird mortalities and unusual etiologies

By:
and
Edited by:
Gerard C. Boere, Colin A. Galbraith, and David A. Stroud

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Abstract

Over the last decade, the National Wildlife Health Center of the United States Geological Survey has documented various largescale mortalities of birds caused by infectious and non-infectious disease agents. Some of these mortality events have unusual or unidentified etiologies and have been recurring. While some of the causes of mortalities have been elucidated, others remain in various stages of investigation and identification. Two examples are discussed: 1) Leyogonimus polyoon (Class: Trematoda), not found in the New World until 1999, causes severe enteritis and has killed over 15 000 American Coot Fulica americana in the upper mid-western United States. The geographic range of this parasite within North America is predicted to be limited to the Great Lakes Basin. 2) In the early 1990s, estimates of up to 6% of the North American population of the Eared Grebe Podiceps nigricollis died at Salton Sea, California, with smaller mortalities occurring throughout the 1990s. Birds were observed to have unusual preening behaviour, and to congregate at freshwater drains and move onto land. Suggested etiologies included interactions of contaminants, immuno-suppression, an unusual form of a bacterial disease, and an unknown biotoxin. During studies carried out from 2000 to 2003, Eared Grebe mortality did not approach the level seen in the early 1990s and, although bacteria were identified as minor factors, the principal cause of mortality remains undetermined. The potential population impact of these emerging and novel disease agents is currently unknown.

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Additional publication details

Publication type:
Conference Paper
Publication Subtype:
Conference Paper
Title:
Recurring waterbird mortalities and unusual etiologies
Chapter:
4.2.6
ISBN:
9780114973339
Year Published:
2006
Language:
English
Publisher:
TSO Scotland Ltd
Publisher location:
Edinburgh, UK
Contributing office(s):
National Wildlife Health Center
Description:
2 p.
Larger Work Type:
Book
Larger Work Subtype:
Conference publication
Larger Work Title:
Waterbirds around the world: A global overview of the conservation, management, and research of the world's waterbird flyways
First page:
439
Last page:
440
Conference Title:
The Waterbirds Around the World Conference
Conference Location:
Edinburgh, Scotland
Conference Date:
April 2004
Other Geospatial:
North America
Online Only (Y/N):
N
Additional Online Files (Y/N):
N