Gibbons under seasonal stress: the diet of the black crested gibbon (Nomascus concolor) on Mt. Wuliang, Central Yunnan, China

Sun

et al. 2008

Int J Primatol

Self Cite

We studied seasonal variation in the activity budget of a habituated group of Nomascus concolor jingdongensis at Mt. via scan sampling at 5-min intervals. The study site is near the northern extreme of the distribution of hylobatids, at high altitude with extreme seasonality of temperature and rainfall. During the day, feeding manifested a bimodal pattern of high activity levels in mid-morning and mid-afternoon, whereas resting reached a peak at midday, with proportionally less time used for traveling. Annually, the group spent an average of 40.0% of the time resting, 35.1% feeding, 19.9% traveling, 2.6% singing, 1.2% playing, and 1.3% in other activities. The proportion of time allocated to activities showed significant monthly variations and was influenced by the diet and temperature. Gibbons increased traveling and playing time and decreased feeding time when they ate more fruit, and they decreased traveling, singing, and playing time and increased feeding time when they ate more leaves. Moreover, when the temperature was low, the gibbons decreased time traveling and increased time resting. In summary, black-crested gibbons employed high-effort activities when they ate more fruit and energy-conservation patterns when they ate more leaves and in low temperature. Behavioral data from the site are particularly useful in understanding gibbon behavioral adaptations to different sets of ecological conditions. Int J Primatol (

Section: Diet and Activity Budgetsmentioning

confidence: 99%

“…High rates of rest among crested gibbons may be due to differences in diet. Compared with the diet of other gibbons (Bartlett 2007), black-crested gibbons ate less fruit and more leaves (Fan et al 2008). As a food class, leaves contain less available calories and more indigestible fiber than those of fruits (Raemaekers 1978).…”

Section: Activity Patternmentioning

confidence: 99%

Seasonal Variations in the Activity Budget of Nomascus concolor jingdongensis at Mt. Wuliang, Central Yunnan, China: Effects of Diet and Temperature

Sun

et al. 2008

Int J Primatol

Self Cite

“…Members preferred fruit when it was available, although they spent nearly equal time feeding on fruit (figs) and on buds and leaves [Fan et al, 2009b]. Two fruit species that were seasonally important (defined as the minimum number of foods comprising 75% of the diet for each month [Fan et al, 2009b]), Choerospondias axillaria and Actinidia callosa , were mostly distributed below 2,100 m, and gibbons would visit them while they were fruiting. The gibbons rarely ranged below 2,100 m when these species were not fruiting.…”

Section: Effect Of Human Disturbance On the Ranging Patternmentioning

confidence: 99%

Altitudinal Ranging of Black-Crested Gibbons at Mt. Wuliang, Yunnan: Effects of Food Distribution, Temperature and Human Disturbance

Jiang²

2010

IJFP

We studied the altitudinal ranging of one habituated group of black-crested gibbons (Nomascus concolor) at Dazhaizi, Mt. Wuliang, Yunnan, China, between March 2005 and April 2006. The group ranged from 1,900 to 2,680 m above sea level. Food distribution was the driving force behind the altitudinal ranging patterns of the study group. They spent 83.2% of their time ranging between 2,100 and 2,400 m, where 75.8% of important food patches occurred. They avoided using the area above 2,500 m despite a lack of human disturbance there, apparently because there were few food resources. Temperature had a limited effect on seasonal altitudinal ranging but probably explained the diel altitudinal ranging of the group, which tended to use the lower zone in the cold morning and the higher zone in the warm afternoon. Grazing goats, the main disturbance, were limited to below 2,100 m, which was defined as the high-disturbance area (HDA). Gibbons spent less time in the HDA and, when ranging there, spent more time feeding and travelling and less time resting and singing. Human activities directly influenced gibbon behaviour, might cause forest degradation and create dispersal barriers between populations.

“…orangutans: Knott & Kahlenberg, 2007;gibbons: Bartlett, 2007], mangrove forest [proboscis monkeys : Bismark, 2010], to temperate forests [Yunnan snub-nosed monkeys: Xiao et al, 2003; Japanese macaques: Hanya, 2004] and grassland [geladas: Iwamoto & Dunbar, 1983]. Foraging animals therefore are required to make decisions regarding which resources to exploit, in order to ensure that they obtain sufficient nutrition and maintain good health [Bartlett, 2009;Fan et al, 2009;McConkey et al, 2003;Pavelka & Knopff, 2004;Stone, 2007]. Even in tropical regions close to the equator, seasonal differences in mean temperature are small but fluctuation in rainfall may be marked, which produces seasonal availability of food resources [Matsuda et al, 2009;McConkey et al, 2003;Pavelka & Knopff, 2004;Stone, 2007].…”

Section: Introductionmentioning

confidence: 99%

“…Alternatively, temperate primates may switch to poorer quality food sources in the lean season [Fan et al, 2009;Poulsen et al, 2001;Xiang et al, 2007], resulting in more time spent feeding in order to compensate for reduced nutritional value [Bartlett, 2009;Nakagawa, 1989]. Moreover, animals living at higher latitudes experience seasonal changes not only in food availability but also ambient temperature [Bartlett, 2009;Fan et al, 2009;Hill, 1997], resulting in energetic challenges associated with thermoregulatory costs [Hanya, 2004]. Nakayama et al [1971] reported that the energy expenditure of outdoor-living captive Japanese macaque (Macaca fuscata) at 5.2 • C is 2.5 times greater than that at 29.5 • C. To save energy, Japanese macaques decrease traveling and feeding when the temperature is low and the thermoregulatory costs are severe [Hanya, 2004].…”

Section: Introductionmentioning

confidence: 99%

Behavioral Responses of Cao Vit Gibbon (Nomascus Nasutus) to Variations in Food Abundance and Temperature in Bangliang, Jingxi, China

Fei²,

Ma³

2012

American J Primatol

The Cao Vit gibbon is a critically endangered species with only about 110 individuals remaining in a degraded karst forest along the China-Vietnam border. Behavioral data from this site are particularly useful in understanding gibbon behavioral adaptations to different sets of ecological conditions and will contribute to the conservation of the species. We studied seasonal variation in the time budget and diet of the Cao Vit gibbon in response to variation in food availability and ambient temperature by observing two groups for 1,379 hr between January and December 2009. We used 5-min scan samples to record the activity of gibbons. Both ambient temperature and food availability varied from month to month. Gibbon groups increased resting time and huddled together in sleeping places in cold months. Gibbons spent more time feeding on fruit when fruit was more abundant suggesting that fruit was their preferred food. Alternatively, leaf eating was negatively correlated with leaf availability which suggested that leaves may be used as a fallback food. Gibbons increased their diet diversity when they ate more leaves. This might be a strategy to cope with toxins or digestion inhibitor accumulation associated with feeding from a limited number of leaf species. Individuals consumed more buds when Broussonetia papyrifera produced buds in March and April. During this period, they decreased traveling time and engaged in less frequent social interactions. Gibbons spent more time searching for and feeding on invertebrates during June and October. However, we did not collect data on invertebrate abundance and therefore cannot determine the relationship between invertebrate feeding and availability. We conclude that flexibility in consuming diverse food types and food species, and in responding to the availability of preferred foods, has enabled the Cao Vit gibbon to survive in a degraded karst forest habitat.