Age-Related Hoarding Strategies in the Crested Tit Parus cristatus: Should the Cost of Subordination be Re-Assessed?

Abstract

1. In a population of crested tits Parus cristatus in northern Belgium, living in group territories outside the breeding season, food was mainly stored during October and November, a time when territorial flocks are split up in age-specific subflocks. 2. First-year flock members frequently stored in the upper and outermost parts of the trees, whereas adults consistently hoarded and foraged in protected sites near the trunk. The outermost, predator-exposed sites were only used by first-year foragers in mixed-age winter flocks with adults, as a result of site competition within flocks on cold days. 3. Consequently, the overlap between foraging sites (protected) and hoarding sites (exposed) of first-year birds was small during autumn, but large during winter