THE ROLE OF AGE AND EXPERIENCE IN THE BEHAVIORAL-DEVELOPMENT OF FOOD-STORING AND RETRIEVAL IN MARSH TITS, PARUS-PALUSTRIS

This study considers the development of food-storing and the spatial memory involved in retrieving caches in juvenile hand-raised marsh tits. The hypothesis that there is a 'sensitive phase' for the onset of food-storing was tested by exposing different groups of birds to their first opportunity to store and retrieve at 35, 60 and 115 days post-hatch. All groups stored within the first few trials after their first storing opportunity. Further comparisons between groups given different amounts of experience from day 35 (nutritional independence) to day 59 showed that the sudden onset in the number of seeds stored at day 44 depends on age rather than experience. Other aspects of food-storing, such as the proportion of seeds that were hidden, the appropriateness of the items stored and the efficiency of carrying seeds to storage sites, developed more gradually and were fully developed around day 44. However, groups given their first opportunity to store and retrieve at days 60 and 115 did not store on the first storing trial and showed a more gradual onset in the amount of food-storing, probably because they required experience of carrying seeds. Memory for retrieving caches developed gradually as a result of experience. However, retrieval performance in the groups given experience from days 60 and 115 developed more rapidly, which suggests that the increase in the rate of retrieval performance is largely a function of age. © 1994 The Association for the Study of Animal Behaviour.