Seed mass plays an important role in seed dispersal of many plants by scatter-hoarding rodents. Previous studies usually focus on seed-mass selection by the whole rodent community while ignore the interspecific variation; and they often obtain inconsistent results.
Researchers from Xishuangbanna Tropical Botanical Garden (XTBG) investigated seed predation and seed hoarding by three sympatric rodent species (red spiny rat Maxomys surifer, Chinese white-bellied rat Niviventer confucianus, and yellow-bellied rat Rattus flavipectus) in semi-natural enclosures in the Xishuangbanna tropical region of southwest China.
The researchers aimed to see whether the three rodent species differed in hoarding behaviors (scatter-hoarding vs. larder-hoarding). They further wanted to know whether the tree rodent species differed in seed mass preference during foraging process.
They found that the hoarding behavior and foraging preference on seed mass during seed dispersal differed greatly among rodent species. M. surifer showed a predominantly scatter-hoarding behavior, N. confucianus showed both scatter- and larder-hoarding behaviors, and R. flavipectus showed a predominantly larder-hoarding behavior.
Differential preferences on seed mass during scatter-hoarding by different rodents and conflicting selective pressures on seed mass at different dispersal stages may lead to inconsistent selective pressures on seed mass of a specific tree species.
“We suggest that differences in hoarding behavior among sympatric rodent species should be considered in future field studies, as this will help us to better understand the role of the whole rodent community in the evolution of seed mass of forest trees that depend on dispersal by rodents”, said Dr. CAO Lin, the first author of the study.
The study entitled “Differential seed mass selection on hoarding decisions among three sympatric rodents” has been published in Behavioral Ecology and Sociobiology.
WANG Bo Ph.D
Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan 666303, China