Risk of predation and foraging activity in shrews
Examined the responses of foraging common shrews Sorex araneus to the presence of a potential predator, weasel Mustela nivalis. A significant short-term (5-15 min) decrease of activity was observed after a visit by the weasel during both low and high level weasel activity. Some shrew individuals decreased their foraging activity to a very low level following the weasel's visits while others did not show any change in activity at all. Magnitude of the shrew's response was positively correlated with its weight at the beginning of the experiment. Under risk of predation, large individuals could affort to decrease their foraging activity at the cost of weight loss but smaller individuals, with smaller body energy reserves, apparently could not do so.