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A natural feeding experiment on a declining snowshoe hare population
Charles J Krebs1, Stan Boutin1, B S Gilbert1
1Department of Zoology, University of British Columbia, V6T 1W5, Vancouver, B.C., Canada.
Oecologia
|March 18, 2017
Summary
Supplemental food did not prevent the cyclic decline of snowshoe hares (Lepus americanus). Hare populations experienced similar declines on both control and experimental areas, indicating food shortage is not the primary driver of these population cycles.
Area of Science:
- Ecology
- Wildlife Biology
- Population Dynamics
Background:
- Snowshoe hare populations exhibit cyclical fluctuations, often linked to food availability.
- Previous research suggested resource limitation as a key factor in population declines.
Purpose of the Study:
- To investigate whether supplemental food could mitigate the cyclic decline of snowshoe hare populations.
- To determine if food shortage is a necessary condition for the population decline phase.
Main Methods:
- Supplemented a 9-hectare area with natural food (downed spruce and aspen trees) over three winters (1981-1984).
- Monitored snowshoe hare survival, reproduction, and growth rates on both experimental and control grids.
- Compared population dynamics between the food-supplemented area and control areas.
Main Results:
- Snowshoe hares readily consumed the supplemental food.
- Population declines occurred at similar rates on both experimental and control grids between 1981 and 1983.
- No significant improvement in hare survival or reproduction was observed on the food-supplemented area.
- Improved growth rates were noted on the food grid during the initial winter of the decline (1981-82).
Conclusions:
- Food shortage is not a necessary factor driving the cyclic decline of snowshoe hare populations in the southern Yukon.
- Other factors likely play a more significant role in regulating snowshoe hare population cycles.
- Supplemental feeding did not alter the fundamental pattern of the hare population cycle.
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