Date of Award

8-17-1996

Document Type

Thesis

Abstract

The roles of weather and parasitic insects in caribou (Rangifer tarandus) ecology were investigated to determine their influence on population dynamics of the Delta Herd. Data on weather, insect abundance, and caribou behavior were collected during two summers. Mosquito season started 21 and 11 June and oestrid fly season 11 July and 21 June in 1994 and 1995, respectively. Mosquito activity was limited by windspeed at temperatures >7°C. Oestrid fly presence was influenced mainly by temperature. Presence of insects and temperature positively influenced, and windspeed negatively influenced rate of activity changes of caribou. Feeding decreased and standing increased with insect presence and temperature. Increasing temperature affected activity budgets even in the absence of insects by decreasing feeding activities. Weather, especially temperature, and parasitic insects, especially oestrid flies, affected caribou mainly by limiting forage intake and increasing energy expenditure. Estimated activity budgets in summers of 1976-1995 indicated possible limiting effects of temperature on population dynamics.

Handle

http://hdl.handle.net/11122/14801

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