Memory decay and cache site preferences in hoarding coal tits — a laboratory study

Abstract

Summary Many animals use hoarding as a long-term strategy to ensure a food supply at times of shortage. This study explores the respective roles of memory and site preferences in cache recovery by coal tits (Periparus ater). We compared the retrieval accuracy or foraging efficiency of the cacher itself (‘caching coal tit’), a naive conspecific (‘pilfering coal tit’) and a non-hoarding heterospecific (‘pilfering great tit’; Parus major) after six different retention intervals. Our experiment shows that the persistence of the coal tits’ memory is up to 4 weeks in the laboratory. Species specific storage and foraging site preferences enhance cache recovery after longer intervals. We find no evidence for individual-specific preferences. Pilfering great tits are capable of learning the coal tits’ hoarding preferences. This ability may affect coal tits’ hoarding behaviour in more natural conditions as they frequently forage in mixed flocks with great tits.