Seed predation and passage time through the digestive tract of captive golden snub-nosed monkeys (Rhinopithecus roxellana)

Abstract

Seed predation and dispersal by mammals are two key processes affecting the dynamics of plant populations and regeneration of forest trees. Colobine monkeys often consume fruits and are usually assumed to be seed predators, but their role as seed dispersers is unclear, especially dispersal universality of small seeds by colobine species. We conducted feeding experiments using the fruits of twelve tree species on four captive individuals of golden snub-nosed monkey (Rhinopithecus roxellana) at the breeding center in Shennongjia National Park. A large proportion of seeds (mean: 70.1%; range: 34.7–100.0%) were destroyed on passing through the digestive tract of the monkeys. The mean retention time (MRT) of seeds in the gut of monkeys was approximately 36 h (range: 28.4–41.7 h). Furthermore, the percentages of seed destruction (PSD) varied among plant species, as did the MRT. But neither PSD nor MRT was correlated with seed size. Golden snub-nosed monkeys appear to be both mild seed predators and potential seed dispersers, particularly of seeds less than 4.3 mm wide. The dispersal of seeds of Celastrus orbiculatus and Rubia ovatifolia may be positively affected by these primates. The role of colobine monkeys for seed dispersal need to be further attention in the future studies.