The Japanese macaque Macaca fuscata is known for its diverse range of habitats and highly seasonally variable diet. But we do not know how seasonal plant food diversity affects monkeys in captive forested enclosures. It is important to know how enrichment with natural vegetation affects the foraging behavior of captive groups. Iwamoto found that nutrient intake of an adult female Japanese macaque on Koshima islet varied across seasons, with protein intake being greater in October and November than other seasons and lipid intake was lower in winter than other seasons. This might be due to the seasonal variation of nutrients of plant items. Nakagawa found that interregional (cool temperate vs warm temperate) differences in the intake of gross energy and protein; with higher in autumn than in winter were responsible for those in nutritional content and feeding rate of food items. Hanya et al. reported that leaves high in protein, ash and protein to neutral detergent fiber (NDF) ratio were selected on Yakushima Island, Japan. They only investigated leaf food selection, based on the nutritional properties of ingested leaf food items, but did not analyze them seasonally. Japanese monkeys in the wild consume both leaves and fruits equally and their dietary diversity varies across seasons. To build on our knowledge of primate feeding ecology in the wild and in captivity, we
conducted nutritional analysis of all major food items (bark, leaf, fruit, nut) for a twelve month period to investigate whether nutritional quality varies seasonally, and whether this affects the monkeys consumption of these major food items. Little information exists on the foraging behavior and dietary composition of captive macaques. A captive forested enclosure provides the opportunity to investigate in more detail how Japanese macaques utilize vegetation (variety of species and their food parts) in a semi naturally forested enclosure and what nutritional properties of this vegetation may affect their consumption of specific plant food items. Such a study also provides an opportunity to evaluate the possible benefits to monkeys in such an enriched enclosure environment by measuring the impact of this extra source of nutrition on their activity budget (e.g., extension of feeding time) and the enhancement of dietary quality. In a previous study, Jaman and Huffman showed that Japanese macaques housed in a forested enclosure spent a nearly equal amount of time feeding on natural plant food items as they did on provisioned food. This had the effect of increasing the total time spent foraging to a proportion of the total activity budget spent feeding similar to that of Yakushima macaques. Based on these results, we asked the following questions, while monkey chow may meet nutritional requirements for basic health maintenance and breeding: 1) when given access to appropriate plant resources, will captive macaques consume a wide variety of plant items from diverse plant species consumed by their wild counterparts? 2) If so, will they ingest items based on the seasonal variability of nutritional content, i.e., consuming items with relatively higher amounts of crude protein, crude lipid and TNC, and relatively lower amounts of fiber? The study group, Wakasa-5 troop, of Japanese macaques was captured from the wild in March 1974 and transported to the Primate Research Institute (PRI), Inuyama, Japan by institutional staff. All members of the present group were born and lived their entire lives together in an outdoor non vegetated enclosure up until April 2004, when they were moved into a newly constructed 6400 m2 naturally forested enclosure. This was the group’s first exposure to a naturally vegetated environment. At the beginning of this study in August 2005, the group consisted of 32 individuals. Due to births, there were 41 individuals by the end of the study in 2006. The enclosure was surrounded by a 2–3 m high fence. Inside were wooden platforms for climbing, resting and socializing. Three small ponds and one artificial narrow water flow provided drinking water. The macaques entered the pools to play and cool off during hot summer months. Source: Animal Discovery-chanel
