Effects of seed traits on the cache size of a scatter-hoarding rodent, Leopoldamys edwardsi

Abstract

Abstract Seed traits can influence post-dispersal seed fate and seedling establishment by manipulating the size of caches made by hoarding animals. However, few studies have explored how seed traits affect cache size and subsequent seed fate mediated by hoarding rodents. In this study, we investigated the effects of seed traits on hoarding behavior of Leopoldamys edwardsi using seeds of Quercus variabilis, Castanea henryi, Camellia oleifera, Lithocarpus harlandii, and Choerospondias axillaris in semi-natural enclosures in Dujiangyan, southwest China, in an attempt to elucidate the relationship between seed traits and cache size. Significant differences were detected in the scatter-hoarding preference of L. edwardsi for seeds of C. axillaris, C. henryi, C. oleifera, Q. variabilis, and L. harlandii. There was a significant difference in the cache size between the five seed species made by L. edwardsi. More importantly, we found that there was a significant positive correlation between the cache size and crude fat but a significant negative correlation between cache size and seed mass as well as crude starch. Our study has revealed that seed traits appear to be a key factor in regulating the hoarding behavior of rodents, mainly the size of their caches. This regulation, in turn, has a significant impact on seed survival and seedling establishment that emerge from the caches. Significance statement At present, a large number of studies focus on a certain trait of a single seed or the effect of a certain seed trait of various species on the hoarding behavior of rodents. How seed traits affect cache size and subsequent seed fate mediated by hoarding rodents remains unknown. This study systematically illustrates how rodents manipulate seed fates and manage cache size according to seed traits. Managing cache size based on different seed traits involves a trade-off between cache recovery and pilferage, which may be an evolutionary strategy of scatter-hoarding animals.