Hoarding decisions by Edward's long-tailed rats (Leopoldamys edwardsi) and South China field mice (Apodemus draco): the responses to seed size and germination schedule in acorns.

Co-varying traits in acorns such as seed size and germination schedule are important to influence the behavioural decisions of hoarding rodents. Using acorn pairs from cork oak (Quercus variabilis) (large size and short germination schedules) serrate oak (Q. serrata) (small size and short germination schedule) and qinggang (Cyclobalanopsis glauca) (small size and long germination schedule) with contrasting seed size and germination schedule, we conducted a series of experiments to investigate hoarding preferences in response to seed size and germination schedule by Edward's long-tailed rats (Leopoldamys edwardsi) and South China field mice (Apodemus draco) in semi-natural enclosures. We found that the seed size hypothesis was consistently supported: both rodent species ate more small acorns but hoarded more large ones regardless of germination schedules. However, the germination schedule hypothesis was also supported when similar sized acorns were simultaneously provided, e.g. Q. serrata versus C. glauca or germinating versus non-germinating Q. variabilis. Our results, contrary to the studies from North America, indicate that seed size is more important than germination schedules in determining whether the tested animals eat or hoard a given seed.