Separating the effects of predation risk andinterrupted foraging upon mass changesin the blue tit Parus caeruleus

The optimal amount of reserves that a small bird should carry depends upon a number of factors,including the availability of food and environmental predation risk levels. Theory predicts that, ifpredation risk increases, then a bird should maintain a lower level of reserves.

Sean A. Rands and Innes C. Cuthill, Proc. R. Soc. Lond. B 7 September 2001 vol. 268 no. 1478 1783-1790