Seed Hoarding And Pilfering Behavior Of Forest Rodents In Dujiangyan Area

Some rodents gather and cache seeds to ensure food supply during period of food shortage.How many seeds they cache and how they deal with those seeds is largely affected by seed traits such as seed size,nutrient content and hardness of the seed coat.Pilferage is a very common phenomenon.Scatter-hoarding seeds can be stolen by the same or different individuals,the seed traits affect the pilfering hehavior,and the seed fate after cache loss.In the process of long-term evolution,the hoarding and stealing selection of plant seeds by the animals will affect the evolution of seed traits to some extent,and the change of plant seed traits will influence various behavioral strategies of the animals.In this study,the effects of seed traits(such as seed size,nutrient composition and seed coat thickness)on the hoarding and pilfering behavior of rodents were systematically studied in the subtropical forest in the Dujiangyan Region,southwestern China.The results of study are as follows:1.Under the semi-natural enclosure conditions,scatter hoarding is the main hoarding way of Edward's long tailed rat(Leopoldamys edwardsi)in Dujiangyan area,combined larder-hoarding behavior.Chevrier's Field Mouse(Apodemus chevrieri)and the South China field mouse(Apodemus draco)exhibit both larder-hoarding behavior and scatter-hoarding behavior.Larder-hoarding is the main hoarding way of Chinese white-bellied rat(Niviventer confucianus)and Chestnut rat(Niviventer fulvescens),which show no scatter hoarding behavior.The pilfering ability of the L.edwardsi,A.chevrieri and A.draco exhibiting scatter hoarding behavior is stronger than N.confucianus and N.fulvescens only performing larder hoarding.2.For Lithocarpus harlandii and Choerospondias axillaris with hard coat in the Dujiangyan area,L.edwardsi of large size is the main disperser and feeder.3.L.edwardsi prefers to cache large seeds,and chooses to eat the small seeds in situation.4.There is a significant negative correlation between the scatter-hoarding r ates and the pilfering rates of the L.edwardsi.There is a very significant posi tive correlation between the larder-hoarding rate and pilfering rate of A.chevrie ri.5.There is a significant correlation between the cache size and the seed mass,crude fat content,crude starch content of the cached seeds by the Edward's long tailed rat.6.The pilfering rate of L.edwardsi to other cached seeds is higher than therecovery rate of their own cached seeds.By driping 1.5% Triton-X 100 to induce olfaction disturbance of L.edwardsi,which increased the proportion of scatter-hoarding seeds and the probability of random digging of empty sand holes in the enclosure significantly,and they tended to recovery their own cached seeds with the help of spatial memory.In the face of two different kinds of non-self cached sites(naive caches and artificial caches).Neither the olfactory impaired L.edwardsi nor the normal L.edwardsi showed any preference for cache pilferage.