Differences in hoarding behavior between captive and wild sympatric rodent species

Abstract

Abstract In hand reared birds and mammals, it is generally considered that the development of hoarding behavior is the result of an interaction between the development and maturation of the nervous system and learning from individual experience. However, few studies have been done on wild animals. We tested differences in hoarding behavior between captive reared and wild individuals of two sympatric small rodents, Korean field mice Apodemus peninsulae and Chinese white-bellied rats Niviventer confucianus. Our aim was to identify if lack of experience from the wild would result in poorly developed hoarding behavior. The Korean field mice perform scatterand larder-hoarding behaviors whereas Chinese white-bellied rats hoard food in larders only. Within outdoor enclosures we compared seed-hoarding behavior in reared juveniles (RJ, 40-50 d old, pregnant mothers were captured in the wild), wild juveniles (WJ, as young as the RJ) and wild adults (WA, over-winter animals). We found that a lack of experience from the wild had significant effects on seed-hoarding behavior for both species. The RJ-group removed and hoarded fewer seeds than the WJand WA-groups. The two latter groups hoarded seeds in a similar way. In the Korean filed mouse the RJ-group placed more seeds on the ground surface than other groups. These findings suggest that wild experience is important for the acquisition of an appropriate food-hoarding behavior (especially for scatter-hoarding) in these species.