Differences in mutualistic or predatory interactions between tree and rodent species as revealed by using a double-duplex passive integrated transponder tagging technique

Abstract

Seed hoarding by rodents plays a significant role in shaping mutualistic or predatory interactions between tree and rodent species in forest ecosystems. However, it is still challenging to identify the seed-rodent interaction at individual level so as to reveal the differences in mutualistic or predatory interactions between seeds and rodents due to lack of efficient methods of tracking seed hoarding behaviour and seed fate. Here, by using the double-duplex passive integrated transponder tagging technique, we investigated seed hoarding behaviour of two rodent species (Niviventer confucianus with larger body size; Apodemus draco with smaller body size) on seeds of two tree species (Quercus variabilis with larger seeds, thicker seed coat, higher tannin and starch contents; Camellia oleifera with smaller seeds, thinner seed coat, and lower tannin but higher fat contents) in a subtropical forest of China. We found N. confucianus preferably consumed and scatterhoarded seeds of Q. variabilis. In contrast, A. draco preferably consumed and scatterhoarded seeds of C. oleifera. Our study showed significant difference in mutualistic or predatory interactions between trees and rodent species, which is likely to be associated with the functional traits of seeds and rodents. Our results suggest that the double-duplex passive integrated transponder tagging technique is useful in quantifying mutualistic or predatory interactions between multiple tree and rodent species.