Seed predation and dispersal by scatter-hoarding rodents are key processes that determine seed survival, and thus, plant regeneration within forests. Most current studies usually focus on just one plant species to study the effect of seed size on seed predation and dispersal by rodents, but, with many of the results remaining equivocal.

Dr. WANG Bo and his supervisor Prof. CHEN Jin of Xishuangbanna Tropical Botanical Garden (XTBG) have kept on studying the interactions of seeds and rodents for many years. They conducted a study in the autumn of 2005 and 2006, in the pine forest of the Shangri-la Alpine Botanical Garden (altitude, 3456 m; 27°54′N, 99°38′E) in Yunnan Province, Southwestern China.

 Theirstudy aimed to obtain a clearer understanding about the effect of seed size on scatter-hoarding rodent preference among species with different dispersal syndromes. They surveyed how scatter-hoarding rodent foraging behavior varied with respect to four species (P. densata , P. armandii , Viburnum sp., and P. densata and Abies sp.) of plants with distinctly different seed sizes and dispersal syndromes in a natural pine forest in the Hengduan Mountains of Southwest China.

 Their results showed that seed size influenced the way that rodents treated seeds encountered by them. Rodents only played an important role in seed dispersal for the species with large seeds (i.e., P. armandii) and purely served as predators for the other three species.

　Their results also indicated that the probability of rodents eating, rather than dispersing and caching seeds increased with decrease in seed size. The scatter-hoarding and caching behavior of rodents offsets limited seed dispersal by large-seeded and wingless species (such as P. armandii), in comparison with that by small-seeded winged species (such as P. densata and Abies sp.) or species with frugivore dispersal (such as Viburnum sp.).

The study entitled “Scatter-hoarding rodents use different foraging strategies for seeds from different plant species” has been published online in Plant Ecology, DOI: 10.1007/s11258-012-0091-8