Trumpeter Swan an indicator of wildlife sustainability in South Coastal British Columbia

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Pacific Coast Trumpeter Swan Population Numbers

*Data from A. Breault, per. com. August, 1999 and also A. Breault, 1999 and 2002 (Draft Report). Migratory Gamebird Populations in Brtitish Columbia: Surveys and Trends. Canadian Wildlife Service, Delta, BC. Note: surveys from 1970 to 1980 cover Vancouver Island only as swan numbers were very low elsewhere on the south coastal area. However from 1988 onwards the Lower Fraser River area has been added to the surveys as wintering swans numbers have built up in this area. To expedite comparisons between fall and mid-winter surveys, mid-winter data is plotted on the year previous to their dates as they measure production and populations from the previous year. For example, the 1995 data refers to counts conducted in the 1995-96 winter.

** Data are from D. Caithamer (1996 and 2001) of the US Fish & Wildlife Service, Office of Migratory Bird Management, Laurel, MD. See references below.

***Preliminary calculations

Midwinter Aerial Surveys of Numbers of Trumpeter Swans on Fraser River Delta*

* Data from S. Boyd, 2002. Environment Canada, Canadian Wildlife Service, Delta, BC. Note: To expedite comparisons between fall and mid-winter surveys, mid-winter data is plotted on the year previous to their dates as they measure production and populations from the previous year. For example, the 1998 data refers to counts conducted in the 1998-99 winter. The Fraser River delta survey area is as described by Boyd (1994).

** A ground count done on January 29, 1998 indicated 1,251 swans (11.2% cygnets) in the Fraser River delta area, with many swans outside the area covered by the regular air surveys.

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References used in the Trumpeter Swan indicator:

• Breault, A. 1999 (Draft Report). Migratory gamebird populations in British Columbia: Surveys and trends. Canadian Wildlife Service, Pacific Wildlife Research Centre, Delta, BC. 30pp.

• Breault, A. 2002 (Draft Report). Migratory gamebird populations in British Columbia: Surveys and trends. Canadian Wildlife Service, Pacific Wildlife Research Centre, Delta, BC. 35pp.

• Boyd, W.S. 1994. Abundance patterns of Trumpeter and Tundra swans on the Fraser River delta, B.C. Pp. 24-36 in: Butler R.W. and K. Vermeer (eds). The abundance and distribution of estuarine birds in the Strait of Georgia, British Columbia, Spec. Publ. Can. Wildl. Serv., Ottawa.

• Caithamer, D.F. 1996. Survey of Trumpeter Swans in North America - April 1996. The Trumpeter Swan Society Newsletter Vol. 25, No. 1: 1-8.

• Caithamer, D.F. 2001. Trumpeter Swan Population Status, 2000. (pdf). U.S. Fish and Wildlife Service.

• Trumpetings. Voice of The Trumpeter Swan Society, Maple Plain, Minnesota Vol. VIII. No. 2. 1998.

• Wilson, L.K., J.E. Elliott, K.M. Langelier, A.M. Scheuhammer and V. Bowes. 1998. Lead poisoning of Trumpeter Swans, Cygnus buccinator, in British Columbia, 1976-1994. Canadian Field-Naturalist 112(2): 204-211.

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