Memory decay and cache site preferences in hoarding coal tits — a laboratory study Lucinda H. Male & Tom V. Smulders 1) (Newcastle University, Centre for Behaviour and Evolution, Henry Wellcome Building for Neuroecology, Framlington Place, Newcastle upon Tyne, NE2 4HH, United Kingdom) (Accepted: 21 April 2007) Summary Many animals use hoarding as a long-term strategy to ensure a food supply at times of short- age. 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 lab- oratory. 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. Keywords: food-hoarding, memory, preferences, learning, persistence, great tit, coal tit. Introduction Food hoarding is the handling of food to conserve it for future use (Vander Wall, 1990) and many animals use it as a long-term strategy to ensure a food supply at times of shortage, e.g., in the winter. Long-term hoarding is likely to evolve if the hoarder is more likely than other individuals to recover their own caches (Andersson & Krebs, 1978). This can be achieved if hoarders employ strategies which enhance their own ability and reduce potential cache pilferers’ abilities to find caches. Larder-hoarders store food in a single large 1) Corresponding author’s e-mail address: tom.smulders@ncl.ac.uk © Koninklijke Brill NV, Leiden, 2007 Behaviour 144, 693-710 Also available online - www.brill.nl/beh