Food culture in seed-eating animals : self-learning or social-learning

低地森林中的日本松鼠（Sciurus lis）有一种特殊的进食技术，可以快速打开核桃壳。然而，生活在针叶林中没有核桃的松鼠没有适当的取食技术来打开核桃壳。研究了年龄对学习取食技术的影响，因此所有一岁以下的个体都能适当地吃核桃，而3岁以上的个体则不能。因此，日本松鼠的核桃取食技术可以通过幼年学习来提高。

The Japanese squirrel(Sciurus lis) in lowland forests has a special feeding technique for quickly opening the walnut shell. However, squirrels living in coniferous forests without walnuts in their habitat did not have a proper feeding technique to open the walnuts shell. The effects of age on learning the feeding technique were examined, so that all individuals younger than one year were able to properly eat the walnuts but individuals older than 3 years were never. Consequently, the walnut feeding technique of the Japanese squirrel can be improved by learning at a young age.