Chang Gang, Xiao Zhishu, Zhang Zhibin
State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
Behav Processes. 2009 Sep;82(1):7-11. doi: 10.1016/j.beproc.2009.03.002. Epub 2009 Mar 14.
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.
橡子的共同变化特征，如种子大小和萌发时间，对于影响贮藏种子的啮齿动物的行为决策很重要。我们使用了栓皮栎（Quercus variabilis）（种子大且萌发时间短）、枹栎（Q. serrata）（种子小且萌发时间短）和青冈（Cyclobalanopsis glauca）（种子小且萌发时间长）的橡子对，这些橡子在种子大小和萌发时间上形成对比，我们在半自然围栏中进行了一系列实验，以研究爱德华长吻松鼠（Leopoldamys edwardsi）和华南田鼠（Apodemus draco）对种子大小和萌发时间的贮藏偏好。我们发现种子大小假说始终得到支持：无论萌发时间如何，这两种啮齿动物都吃掉更多小橡子，但贮藏更多大橡子。然而，当同时提供大小相似的橡子时，例如枹栎与青冈，或者萌发的栓皮栎与未萌发的栓皮栎，萌发时间假说也得到了支持。与北美研究结果相反，我们的研究结果表明，在决定受试动物是否吃掉或贮藏某种给定种子时，种子大小比萌发时间更重要。
