Infrared-triggered remote cameras were used on a 24-h observation of fruit consumption by vertebrates on the forest floor in the Pasoh Forest Reserve, Negeri Sembilan, Peninsular Malaysia, from July 1993 to May 1995. There were two peaks of flowering, in February-April and October. Fruiting showed less seasonality than flowering and fluctuated from year to year. Nearly 4000 photos of animals were obtained and 34 animal species were identified. The 16 most dominant frugivorous species were analysed: 13 species of mammal, two species of bird and one species of reptiles. The pig-tailed macaque (Macaca nemestrina) was the most common visitor, using 44 out of 49 plat species. Six edible parts from five fruit species (Pithecellobium bubalium, Garcinia nervosa, Knema hookeriana, Myristica cinnamomea and M. elliptica) of the porcupine (Trichys fasciculata)-favoured fruits and other fruits consumed by other animals were analysed for nutrient content. Nutrient contents varied widely among fruits: moisture 8.8-90.5%, protein 1.6-13.6%, lipid 0.03-55.0% and NFE 0.8-52.0% on a fresh matter basis. The gross energy was estimated in the range of 1.8-28.7 kJ/g. The porcupine-favoured fruits were rich in nutrients and energy. No frugivore showed a significant preference for either green or coloured fruits.

The time it takes for ingested seeds to pass through the gut of animals is an important aspect of endozoochorous seed dispersal because it influences seed dispersal distance. Variations in the physical characteristics of seeds, such as their weight, volume, and specific gravity, can affect their movement through the gastrointestinal system of a given animal. We conducted feeding experiments with captive Japanese martens, Martes melampus (n=4), at Toyama Municipal Family Park Zoo, central Japan to examine the effects of the physical characteristics of seeds on their passage times. The mean (±SD) transit time, mean retention time, and time of last appearance of four different types of commercial seeds were 2.6±0.3 h (range 0.6-5.4), 9.7±1.1 h (3.8-17.3), and 23.8±3.1 h (12.2-51.8), respectively. All of these values are greater than those found during previous experiments conducted with mustelids. Similar to previous studies, however, none of these passage time variables was correlated with the physical characteristics of seeds. Our results thus indicate that martens disperse seeds of different plant species, whose size, volume, and specific gravity all fall within the range of those used in the present study, from parent plants at similar distances.

To examine the effects of food intake on the gastrointestinal passage time of seeds in the Japanese marten (Martes melampus), we conducted four feeding experiments using captive animals (n = 4). We estimated passage time variables (transit time and mean retention time) of plant seeds (two types) using two different numbers of chicks (single and three) representing two seasons when the animal prey is abundant/scarce. There was no significant relationship between food intake and passage time, and seed type did not affect the passage time variables. Our results were different to those for herbaceous/omnivorous mammals, in which a shorter passage time was observed when food intake increased. The stability in the passage time of the martens could be attributed to the higher level of digestibility of the animal prey. Our data also suggests that martens possess an elastic gut that can expand in volume, which leads to a consistent passage time despite the increase in food intake and enables them to efficiently assimilate nutrients from the consumed food. The results of the present study suggest that the dispersal distance of seeds and defecation site density of martens is influenced by their ranging/activity pattern and not by their digestive physiology.

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