This study was conducted to identify aspects of the breeding ecology of white pelicans (Pelecanus erythrorhynchos) in British Columbia and to develop a management plan to preserve and enhance white pelicans and their habitat in British Columbia. Field studies were conducted during the breeding seasons from 1977 to 1980.
The major migratory route of white pelicans in British Columbia occurs in the Okanagan Valley. Pelicans arrive at Stum Lake, the only known breeding location in British Columbia, in mid April and remain on the Fraser Plateau until late September. Eighty-three percent of all pelicans observed in British Columbia during the summer were located within 80 km of the breeding lake. Chilcotin Lake, approximately 70 km west of Stum Lake, was the primary foraging site during the study. Identification of bone samples collected on the breeding island indicate that pelicans in British Columbia prey chiefly on non-game fish species, such as sucker (Catostomus spp.).
Pelicans at Stum Lake selected flat unvegetated areas to nest. The presence of herring gulls (Larus argentatus) did not appear to affect their nesting distribution. Inter-nest distances were calculated in 1977 and 1978 and found to be similar to distances recorded for other white pelican colonies in North America.
Mean clutch size of white pelicans at Stum Lake during years without disturbance was 1.95 ± 0.21. Mean egg mortality was 10% of all eggs laid. Nest abandonment was the major mortality factor. Nestling and fledgling mortality claimed a
further 26% and 20% respectively, of all eggs laid. Total mortality of young during 1977 and 1978 was 56% of all eggs produced. In years when coyote predation or human disturbance occurred, survivorship of young, and overall productivity of the colony was reduced. The potential impact of coyote predation and human disturbance were examined over longer periods by using a simple simulation model.
The results of this study were discussed in terms of potential management practices that would enhance white pelicans in British Columbia. / Forestry, Faculty of / Graduate
| Identifer | oai:union.ndltd.org:UBC/oai:circle.library.ubc.ca:2429/23132 |
| Date | January 1982 |
| Creators | Dunbar, David Leonard |
| Source Sets | University of British Columbia |
| Language | English |
| Detected Language | English |
| Type | Text, Thesis/Dissertation |
| Rights | For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use. |
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