Animal scatter-hoarding behavior and its impact on the regeneration of plant populations

Scatter-hoarding is one of the most important foraging strategies for many animals. For animals whose hoarding targets are seeds,the hoarding behavior is directly affected by many factors relevant to seeds,including their size,the nutrient content,and secondary metabolites inside the seeds. Animals prefer larger seeds that are delivered and scatterhoarded somewhere far away from the food sources. Smaller seeds are eaten on the spot by animals in compensation for the energy consumed during the hoarding process. Hoarding animals retrieve the food at the cache sites mainly according to the following: spatial memory,particular paths,and direct clues around the cache sites. During the retrieval process,some cache sites are forgotten or missed by the hoarding animals,and these seeds become potential pools for the regeneration of some plant populations. Therefore, scatter-hoarding animals play two roles in ecological systems: they are not only consumers,but also circulators,of seeds. The serial behavior of scatter-hoarding animals( i. e.,retrieval,delivery,and storage),directly influence both the survival of seeds and creation of seedlings. Furthermore,to some degree,the regeneration and distribution of certain plant populations are affected by the behavior of scatter-hoarding animals. As for plant populations,the most urgent mission is to protect their own seeds. In other words,in order to avoid being consumed and to decrease the forage rate by animals,the plant populations have gradually formed multiple and various adaptivestrategies during the evolutionary process. Following a brief statement of conception and research background of hoarding behavior,the main text of this paper comprises four parts. In the first part,the evolution of scatter-hoarding behavior is discussed. In the second part,the process of scatter hoarding is divided into four sections. First,we consider how hoarding animals select their hoarding targets,including( i) the determination of seed quality by hoarding animals,( ii) the effect of nutrients inside the seeds on animal hoarding,( iii) the effect of seed size on animal hoarding,and( iv) the effect of secondary metabolites inside the seeds on animal hoarding. Second,we consider the delivery and storage of seeds by animals. Third,we review the retrieval behavior of hoarding animals( e. g.,spatial memory,particular path,and relevant direct clues). In the third part of the paper,we elaborate the influence of animal scatter-hoarding behavior