Fish-eating bird abundance in oligotrophic lakes in Kejimkujik National Park, Nova Scotia, Canada
- 73 Downloads
Aquatic bird population data in 40 oligotrophic lakes and ponds in Nova Scotia, Canada indicates that only lakes > 20 ha support territorial pairs of Common Loon (Gavia immer) and only lakes ≥ 40 ha produce their young. Broods of Common Merganser (Mergus merganser americanus) occurred in lakes > 25 ha and loon and merganser broods together occurred only in lakes ≥ 80 ha. The fish production in the lakes was estimated from the total phosphorus vs fish yield relationship obtained in similar, oligotrophic lakes in Ontario. Considering the fish consumption and mergansers until fledging along with the maintenance of the adults during the same period (about 200 and 130 kg fish respectively) and the estimated fish production in these lakes, there is a close balance between the size of water body and its fish production to the occupancy and production of piscivorous birds.
Key wordsPiscivorous birds aquatic bird production Common Loon and Common Merganser
Unable to display preview. Download preview PDF.
- Barr, J. F., 1973. Feeding biology of the Common Loon (Gavia immer) in oligotrophic lakes of the Canadian Shield. Ph.D. thesis, Univ. Guelph, Ont. Canada, 204 pp.Google Scholar
- Kelso, J. R. M., 1985. Standing stock and production of fish in a cascading lake system on the Canadian Shield. Can. J. Fish aquat. Sci. 42: 1315–1320.Google Scholar
- Kelso, J. R. M., 1988. Fish community structure, biomass and production in the Turkey Lakes Watersheds, Ontario. Can. J. Fish. aquat. Sci. 45 (Suppl. 1): 115–120.Google Scholar
- Kerekes, J., 1990. Possible correlation of common loon population with the trophic state of a water body. Verh. int. Limnol. 24: 349–353.Google Scholar
- Vollenweider, R. A., 1976. Advances in defining critical loading levels for phosphorus in lake eutrophication. Mem. 1st. ital. ldrobiol. 44: 53–83.Google Scholar
- Vollenweider, R. A. & J. Kerekes, 1980. Synthesis report. Cooperative Programme on Monitoring of Inland Waters (Eutrophication Control). Rep. Technical Bureau, Water Management Sector Group, Organization for Economic Cooperation and Development (OECD), Paris 290 pp.Google Scholar
- White, H. C., 1957. Food and natural history of mergansers on salmon waters in the Maritime Provinces of Canada. Fish. Res. Bd Can. Bull. 116: 1–63.Google Scholar