Seed dispersal and predation by Yakushima macaques, Macaca fuscata yakui, in a warm temperate forest of Yakushima Island, southern Japan

Abstract

The relationships between fruit morphology and the foraging behavior of the Yakushima macaque, Macaca fuscata yakui were studied during a 9‐month field study and series of laboratory experiments on Yakushima Island, southern Japan. These relationships may affect seed germination traits through seed dispersal. The macaques’ foraging behavior was observed in order to obtain data concerning the treatment of pulp and seeds. Seeds in feces and spat seeds were collected and analyzed. A linear discriminant analysis of the data led to the following results: (i) an increase in the relative flesh volume of a fruit was one of the potential factors which increased the probability of seed dispersal by the macaques; and (ii) seed size was an important parameter in relation to the type of seed dispersal (by defecation or spitting out). The germination test was conducted in a laboratory, then the germination rates and delays of dispersed seeds were compared with those of seeds collected directly from trees. The germination of dispersed seeds of Ficus thunbergii, Eurya japonica, and Vaccinium bracteatum, was significantly enhanced by passage through the macaques’ gut. The enhanced germination behavior was not seen in larger seeds, such as those of Psychotria serpens, Myrsine seguinii, Diospyros morrisiana, and Neolitsea sericea. The germination enhancement in small‐seeded plants could be due to a sorting effect from the passage through the gut, which selects seeds with a narrower range of germination traits.

Seed dispersal and predation of fleshy-fruited plants by Japanese macaques in the cool temperate zone of northern Japan.

“…in both study areas, in particular P. ssiori and P. grayana, were approximately 5 mm in diameter (Nakayama et al 2000). The maximum size of seeds studied (4.1 mm or approximately 5 mm) was smaller than that swallowed and dispersed in Yakushima Island (6.35 mm, Elaeocarpus japonicus; Otani and Shibata 2000), implying that the macaque swallowed these seeds leaving some margins.…”

Spatial distribution patterns of trees at different life stages in a warm temperate forest

“…The explanation is probably different for each species, because among a variety of dispersal systems, animal, wind, and/or gravitydispersed species show different fecundities, dispersal distances, and clumping. Because 12 out of 17 species were animal-dispersed, seeds of these species should have been dispersed far from the mother trees by frugivorous birds and/or monkeys in this area (Noma and Yumoto 1997;Yumoto et al 1998;Otani and Shibata 2000). Seeds of these species were dispersed in a wider and more even fashion among topographic positions than trees of the adult stages (Fig.…”

“…Bedd., had capsules, and their seeds were dispersed by gravity and wind. Seeds of T. gymnanthera are also thought to be dispersed by the Japanese macaque Macaca fuscata yakui and birds (Noma and Yumoto 1997;Yumoto et al 1998;Otani and Shibata 2000).…”

Endozoochorous seed dispersal by Japanese macaques (Macaca fuscata): Effects of temporal variation in ranging and seed characteristics on seed shadows

“…Further, ingestion by macaques enhanced germination for seeds of several plant species [Otani & Shibata, 2000], although many seeds were masticated before ingestion [Otani, 2004;Tsuji et al, 2010b]. A recent study found that the topography of dispersed seeds matched the distribution of trees of target plants, which implies that the macaques contribute to the colonization and expansion of plant populations [Tsujino & Yumoto, 2009].…”

“…Japanese macaques primarily feed on fleshy fruits and nuts throughout their range, especially in fall (September-November; reviewed in Tsuji, 2010, Tsuji et al, 2015, and defecate and spit out seeds of 12-35 plant species [Otani & Shibata, 2000;Tsuji, 2011Tsuji, , 2014Tsuji et al, 2011] inside forests. Further, ingestion by macaques enhanced germination for seeds of several plant species [Otani & Shibata, 2000], although many seeds were masticated before ingestion [Otani, 2004;Tsuji et al, 2010b].…”