Dietary selection by yakushima macaques (Macaca fuscata yakui): The influence of food availability and temperature

I examined dietary selection by Yakushima macaques (Macaca fuscata yakui)in relation to food availability and air temperature. Multiple regression analysis indicates that both food availability and temperature influenced the selection of foods. Feeding on young leaves, seeds, and flowers was affected more by availability, while feeding on fruits, mature leaves, and fallen seeds was affected more by temperature. Feeding on insects is strongly correlated with temperature,perhaps because availability of insects increased with temperature. These results suggest that temperature influences dietary selection of Yakushima macaques by changing the energy expenditure required for thermoregulation and through its influence on the accessibility to insects, which are an important protein source for the monkeys.     

Rapid shifting of foraging pattern by Yakushima macaques ( Macaca fuscata yakui ) in response to heavy fruiting of Myrica rubra

We describe short-term changes in foraging behavior by wild Yakushima macaques (Macaca fuscata yakui),which inhabit a warm-temperate broad—leaved forest on Yakushima Island (30°N, 131°E), Japan. Rapid changes of dietary composition, activity budget, and range use by the monkeys occurred from May to June, apparently associated with changes in the availability of the fruit of Myrica rubraBefore the fruit ripened, monkeys spent less time moving and more time feeding on many species of leaves, which accounted for 40% of feeding time. However, when M. rubrabegan to ripen, they fed intensively on the fruit, which accounted for three-fourths of feeding time,though the activity budget remained unaffected As fiuit of M. rubradecreased,the monkeys fed more on the fruit of other species and on insects, and spent more time moving at higher speeds. There marked shifts in foraging pattern occurred within only two months. In terms of moving cost and dietary quality,Yakushima macaques shifted their foraging pattern according to the availability of M. rubrafrom a “low-cost, low-yield” strategy to a “low-cost, high-yield” strategy, and then to a more costly strategy. The ability to make such rapid shifts in foraging pattern may allow the macaques to effectively use the highly variable food supply within their small range.     

Foraging strategies of yakushima macaques (Macaca fuscata yakui )

I investigated the activity budget and diet of Yakushima macaques (Macaca fuscata yakui,)in warm temperate broad- leaved forest of Yakushima, Japan. Both time spent feeding and time spent moving varied considerably between half- months. However, total time spent in active behaviors— feeding time plus moving time— was stable. The composition of the diet also showed considerable variation between half- months. The macaques fed mainly on fruits, seeds,mature leaves, fallen seeds, flowers, and young leaves, each of which accounted for more than 30% of feeding time in at least 1 half- month. They also ate insects and fungi, but each of them comprised ≤ 25 and ≤ 8% of feeding time in any half- month, respectively. Time spent feeding on mature leaves, young leaves, flowers, or fallen seeds is positively correlated with total time feeding and is negatively correlated with time moving. In contrast, time feeding on fruits, seeds, insects or fungi is negatively correlated with time feeding and is positively correlated with time moving. Foraging on foods that have a low energy content, a high density, and a relatively even distribution— mature leaves— or that need much manipulation to be processed— flowers and fallen seeds— increased feeding time, while foraging on foods for which monkeys must search intensively in the forest— fruits, seeds, insects, and fungi— led to increased moving time. I examined foraging strategies of Yakushima macaques in terms of moving costs and the quality of food items. Regarding time feeding on fruits, which have more energy and may need less manipulation than other foods, as a benefit, and moving time as a cost, they seemed to employ a strategy that balanced the costs and benefits of foraging.     

Summer dietary compositions of sika deer on Yakushima Island,southern Japan

Summer food habits of Sika deer (Cervus nippon yakushimae) on Yakushima Island, southern Japan, were studied focusing in particular onPseudosasa owatarii, a dwarf bamboo native to the island. Fecal analyses showed that the food habit of the Sika deer on Yakushima island was plastic: the dietary composition was dominated by graminoids (ca. 90%), particularlyP. owatarii (50%–60%) in the bamboo grassland of theP. owatarii zone above the timber line, whereas leaves and non-leafy parts of woody plants were important in the crytomeria forest and evergreen broad-leaved forest below the timber line. The maximum culm age ofP. owatarii was 8.5 yr, but the majority of leaves (97.8%) were younger than 2.5 yr. Since the weight contribution of the leaves is great (27.7%) and the turnover rate is high, theP. owatarii grassland affords a good foraging place for the Sika deer on Yakushima Island.     

Seasonal variation in the feeding behavior and diet of Japanese macaques (Macaca fuscata yakui) in lowland forest of Yakushima

The feeding behavior of the southern subspecies of Japanese macaque (Macaca fuscata yakui) was studied over a period of 18 months in warm temperate broad-leaved forest on the island of Yakushima, Japan. Focal animal data were collected for the eight adults in the troop. Over a full annual cycle, 35.0% of foraging on identified foods was on leaves and shoots, 30.2% on fleshy fruit, 13.2% on seeds, and 5.5% on flowers. Invertebrates and other animal matter accounted for 10.3% of foraging and fungi for 4.6%. There was marked seasonal variation in the use of different food categories, and seeds, leaves, fleshy fruit, and animal matter were each predominant at different times of year. There was also evidence of annual cyclicity in patterns of foraging on all major food types. The monkeys spent less time moving and ate a greater variety of foods when feeding on leaves than when feeding on fruit and seeds, or on insects. Time spent foraging was positively correlated with diversity of the diet, but there was no simple relationship between time spent foraging and the predominant food type. This suggests that a wide variety of foods takes longer to harvest and process, irrespective of the food type. The diet of the study troop was flexible and could not be assigned to a simple dietary category, such as frugivorous or folivorous. If these data are representative of the subspecies, the Yakushima macaque is much more of a dietary generalist than most primates for which there are adequate data. Am. J. Primatol. 43:305–322, 1997. © 1997 Wiley-Liss, Inc.     

Food Items Consumed by White-headed Langurs in Fusui, China

We studied the socioecology of white-headed langurs (Trachypithecus leucocephalus) from September 1997 to September 1998 in Fusui Precious Animal Reserve, SW Guangxi, China. We collected data on climate, phenology of food plant species, and foods consumed by langurs living in habitats with different levels of human disturbance. Feeding records showed that the most food is from less common plant species. Young leaves were the staple food item in all langur groups, and consumption correlates with availability. Consumption of mature leaves is not significantly correlated with their availability, but the langurs fed on them, and other food items such as fruits and seeds, when the availability of young leaves was low. Langurs in different areas had broadly similar diets, but they varied most in the proportion of supplementary items such as fruit. Groups in more disturbed habitat did not increase the overall proportion of mature leaves in their diet, but instead maintained their intake of young leaves from a greater diversity of species, and incorporated more immature fruit. Conservationists should direct efforts toward protection of rare plant species providing preferred food items, particularly supplementary foods at times when, and in areas where, preferred food items are less available.     

Fruit diet of Alouatta guariba and Brachyteles arachnoides in Southeastern Brazil: comparison of fruit type, color, and seed size

Fruit is an important food resource for neotropical primates. In this study I compare the fruit diet of sympatric brown howlers (Alouatta guariba) and southern muriquis (Brachyteles arachnoides). Feeding behavior was studied over 12 months and fruit species consumed were identified and assigned to the categories fruit type, fruit color, and seed size. Observed-fruit feeding records were compared with expected records determined from local availability of the fruit of the tree species. I also determined dietary overlap. Fruit consumption occupied 8 and 12% of the feeding time of A. guariba and B. arachnoides, respectively. Fruit from eight tree species were consumed by the former and fruit from twenty-two species by the latter. Patterns of fruit selection of A. guariba and B. arachnoides varied widely. Although howlers and muriquis converge behaviorally by selecting fruit with common attributes (fleshy/unprotected, violet and brown/black-colored), unlike A. guariba, B. arachnoides fed on immature seeds of fleshy/protected and dry fruit. Large seeds were ingested, and defecated intact, by B. arachnoides only. There was little overlap of fruit diet even within categories that had been selected by both, suggesting that dietary divergence is occurring at the interspecific level. Different resource exploitation probably mediates the coexistence of A. guariba and B. arachnoides in low diversity, semideciduous forests, where the environment imposes narrow limits on primate food choices.     

Rapid shifting of foraging pattern by Yakushima macaques (Macaca fuscata yakui) in response to heavy fruiting ofMyrica rubra

We describe short-term changes in foraging behavior by wild Yakushima macaques (Macaca fuscata yakui),which inhabit a warm-temperate broad—leaved forest on Yakushima Island (30°N, 131°E), Japan. Rapid changes of dietary composition, activity budget, and range use by the monkeys occurred from May to June, apparently associated with changes in the availability of the fruit of Myrica rubraBefore the fruit ripened, monkeys spent less time moving and more time feeding on many species of leaves, which accounted for 40% of feeding time. However, when M. rubrabegan to ripen, they fed intensively on the fruit, which accounted for three-fourths of feeding time,though the activity budget remained unaffected As fiuit of M. rubradecreased,the monkeys fed more on the fruit of other species and on insects, and spent more time moving at higher speeds. There marked shifts in foraging pattern occurred within only two months. In terms of moving cost and dietary quality,Yakushima macaques shifted their foraging pattern according to the availability of M. rubrafrom a “low-cost, low-yield” strategy to a “low-cost, high-yield” strategy, and then to a more costly strategy. The ability to make such rapid shifts in foraging pattern may allow the macaques to effectively use the highly variable food supply within their small range.     

Foraging strategies of yakushima macaques(Macaca fuscata yakui)

I investigated the activity budget and diet of Yakushima macaques (Macaca fuscata yakui,)in warm temperate broad- leaved forest of Yakushima, Japan. Both time spent feeding and time spent moving varied considerably between half- months. However, total time spent in active behaviors— feeding time plus moving time— was stable. The composition of the diet also showed considerable variation between half- months. The macaques fed mainly on fruits, seeds,mature leaves, fallen seeds, flowers, and young leaves, each of which accounted for more than 30% of feeding time in at least 1 half- month. They also ate insects and fungi, but each of them comprised ≤ 25 and ≤ 8% of feeding time in any half- month, respectively. Time spent feeding on mature leaves, young leaves, flowers, or fallen seeds is positively correlated with total time feeding and is negatively correlated with time moving. In contrast, time feeding on fruits, seeds, insects or fungi is negatively correlated with time feeding and is positively correlated with time moving. Foraging on foods that have a low energy content, a high density, and a relatively even distribution— mature leaves— or that need much manipulation to be processed— flowers and fallen seeds— increased feeding time, while foraging on foods for which monkeys must search intensively in the forest— fruits, seeds, insects, and fungi— led to increased moving time. I examined foraging strategies of Yakushima macaques in terms of moving costs and the quality of food items. Regarding time feeding on fruits, which have more energy and may need less manipulation than other foods, as a benefit, and moving time as a cost, they seemed to employ a strategy that balanced the costs and benefits of foraging.     

Diet of a Japanese Macaque Troop in the Coniferous Forest of Yakushima

I studied the diet of a troop of Japanese macaques in the coniferous forest of Yakushima over one year via focal animal sampling. Fiber-rich foods constituted 45% of annual feeding time, and mature leaves constituted 38% of total feeding time. Feeding time on fruits and seeds was only 13% and 4%, respectively. Flowers and fungi contributed a considerable amount of annual feeding time: 15% and 14%, respectively. Their diet changed seasonally. They fed on more fruits and seeds in response to increased availability, and when these foods were not available, they ate mature leaves. When the temperature was low, they ate more herbs, possibly to save energy by not climbing trees and staying in sunny places. The results imply two dietary characteristics of the species that might relate to adaptations in temperate regions, where fruit is available during a limited season and fiber-rich foods are the only candidate of fallback food. They are capable of digesting a large amount of fiber-rich food, but at the same time they preferentially select high-quality fruits or seeds when they are available.     

Selectivity and Variability in the Diet of Milne-Edwards' Sifakas (Propithecus diadema edwardsi): Implications for Folivory and Seed-Eating

Propithecus diadema edwardsi combines a strategy of high selectivity for many food items with the use of more readily available and abundant foods. Selectivity is seen in relation to taxonomic affiliations of plants eaten, forest composition, and phenological patterns. Feeding time is concentrated on relatively uncommon species as indicated by high selection ratios. Annual and monthly dietary diversity is low, with food choices restricted to a relatively narrow set of species: a total of 82 and 73 plant species were eaten by the two groups of which, only 22 and 16% contributed >1% feeding time, however, these values fall with commonly reported ranges. Plant parts eaten varied widely from month to month, with overall variance in seed-eating higher than variance in young or mature leaf feeding. No correlation between percentage feeding time and food availability is significant; instead, monthly feeding patterns are better explained by the availability of particular plant species, which also supports a view of high selectivity in food choice. In contrast to selectivity for many seed, whole fruit, and new leaf sources, reliably abundant food sources appear to be leaves from lianas, epiphytes, and parasites, which were eaten in all focal months. While dramatic interannual differences in dietary composition in response to the absence of a preferred seed source highlight the interpretation of folivores as surviving food crunches by turning to readily available, poor quality resources, this strategy is not unique to folivores.     

Fallback Foods of Red Leaf Monkeys (Presbytis rubicunda) in Danum Valley, Borneo

Animals in Southeast Asia must cope with long periods of fruit scarcity of unpredictable duration between irregular mast fruiting events. Long-term data are necessary to examine the effect of mast fruiting on diet, and particularly on the selection of fallback foods during periods of fruit scarcity. No such data is available for colobine monkeys, which may consume substantial amounts of fruits and seeds when available. We studied the diet of red leaf monkeys (Presbytis rubicunda, Colobinae) in Danum Valley, Sabah, northern Borneo, using 25 mo of behavioral observation, phenology and vegetation surveys, and chemical analysis to compare leaves eaten with nonfood leaves. The monkeys spent 46% of their feeding time on young leaves, 38% on seeds, 12% on whole fruits, 2.0% on flowers, 1.0% on bark, and 1.2% on pith. They spent more time feeding on seeds and whole fruit when fruit availability was high and fed on young leaves of Spatholobus macropterus (liana, Leguminosae) as fallback foods. This species was by far the most important food, constituting 27.9% of the total feeding time, and the feeding time on this species negatively correlated with fruit availability. Consumed leaves contained more protein than nonconsumed leaves, and variation in time spent feeding on different leaves was explained by their abundance. These results suggest that red leaf monkeys show essentially the same response to the supra-annual increase in fruit availability as sympatric monogastric primates, increasing their seed and whole-fruit consumption. However, they depended more on young leaves, in particular Spatholobus macropterus, as fallback foods during fruit-scarce periods than did gibbons or orangutans. Their selection of fallback food appeared to be due to both nutrition and abundance.     

Influence of Forest Seasonality on Gibbon Food Choice in the Rain Forests of Barito Ulu,Central Kalimantan

We describe the diet of two hybrid gibbon groups (Hylobates mulleri x H. agilis) in relation to forest seasonality. We collected data over 12 mo in lowland dipterocarp forest in the Barito Ulu research area, Central Kalimantan, Indonesia. Although non-fig fruit was the main dietary item (52–64% of diet), gibbon diet was most strongly influenced by the availability of flowers. During periods when flowers were most abundant and the gibbons increased consumption of them, they also ate figs or young leaves more often. We suggest that although flowers are nutritionally rich sources of food, providing relatively high levels of protein compared to fruit, they are unlikely to satiate gibbon hunger and they seek dietary bulk from figs or young leaves, because they are easily obtained. Rainfall also influenced food choice, and non-fig fruit availability had a weak influence on fruit selection for one group. The group concentrated feeding on the fruit of a few species when fruit was most abundant and ate a greater diversity of species when fruit was scarce. Gibbon diet appeared not to be influenced by changes in availability of figs, young leaves and diversity of fruiting species.     

内蒙古库布齐沙地黑线仓鼠食物构成的季节变化

黑线仓鼠 (Ｃｒｉｃｅｔｕｌｕｓｂａｒａｂｅｎｓｉｓ)是广泛分布于我国华北和中原地区草原、农田的一种农牧业害鼠[8] ,在这些生境中 ,其食物以各种农作物和牧草种子为主 ,并取食大量昆虫[1,3 ,5,6 ] 。在鄂尔多斯高原库布齐沙地环境中 ,由于该种耐受高温环境的能力相对较低 ,仅分布在郁蔽程度较高的固定沙地和农田。研究表明 ,本地区该种的数量近年呈上升趋势[2 ] 。结合研究其数量变动规律 ,我们于 1996年 4～ 10月对其食物构成的季节变化进行了研究 ,以分析其生态适应对策。1　研究方法研究点设在库布齐沙地东段的中国农业科学院草原研…     

Feeding ecology of the long-tailed macaque(Macaca fascicularis) in Kalimantan Tengah,Indonesia

I studied long- tailed macaque (Macaca fascicularis)feeding behavior and ecology as part of a larger behavioral ecological study at the Natai Lengkuas Station, Tanjung Puting National Park, Kalimantan Tengah, Indonesia. I collected data on feeding behavior via scan sampling of all visible individuals in the focal group (approximately 800 observation hours). I established vegetational plots and monitored them monthly to determine food availability and abundance. I found long- tailed macaques to be primarily frugivorous;leaves, flowers, insects and bark provided the remainder of the diet. They used at least 33 plant species as food sources, but >60% of the diet was provided by only 5 species. Based on previous vegetational analyses, these tree species were among the highest in relative density. However, selection ratios for 19 food species indicate that 13 of them were selected more often than expected. Long- tailed macaques appear to be selective feeders but can exploit a variety of food sources during periods of food scarcity.     

Seasonal Effects on Reconciliation in Macaca fuscata yakui

Dietary composition may have profound effects on the activity budgets, level of food competition, and social behavior of a species. Similarly, in seasonally breeding species, the mating season is a period in which competition for mating partners increases, affecting amicable social interactions among group members. We analyzed the importance of the mating season and of seasonal variations in dietary composition and food competition on reconciliation in wild female Japanese macaques (Macaca fuscata yakui) on Yakushima Island, Japan. Yakushima macaques are appropriate subjects because they are seasonal breeders and their dietary composition significantly changes among the seasons. Though large differences occurred between the summer months and the winter and early spring months in activity budgets and the consumption of the main food sources, i.e., fruits, seeds, and leaves, the level of food competition and conciliatory tendency remained unaffected. Conversely, conciliatory tendency is significantly lower during the mating season than in the nonmating season. Moreover, conciliatory tendency is lower when 1 or both female opponents is in estrous than when they are not. Thus the mating season has profound effects on reconciliation, whereas seasonal changes in activity budgets and dietary composition do not. The detrimental effects of the mating season on female social relationships and reconciliation may be due to the importance of female competition for access to male partners in multimale, multifemale societies.     

Effects of diet, photoperiod and temperature on the postdiapause reproduction in the cabbage bug,Eurydema rugosa

InEurydema rugosa Motschulsky (Heteroptera: Pentatomidae), the type of food supplied (i.e. seeds or leaves of the brown mustard,Brassica juncea Hemsel) and photoperiod, which control the induction of adult diapause, do not play a role in the initiation of reproduction after overwintering. A temperature above 13.2°C was required to start reproduction. After its initiation, however, short-day conditions on seeds induced diapause again in some adults. Although a diet of seeds under long-day conditions, in common with short-day conditions, induced diapause in young adults (Numata & Yamamoto, 1990), it did not reinduce diapause in adults after overwintering. Thus,E. rugosa that had overwintered became sensitive to diapause-inducing photoperiod again but not to dietary factors.     

Diet of the brown hare (Lepus europaeus) and food availability in northern Patagonia (Mendoza, Argentina)

The brown hare, a Leporid widespread in the world, is now dispersed across Argentina after its introduction at the end of the 19th century. Studies on hare feeding ecology are important to evaluate a potential competition with domestic and native wild herbivores. This study analyses the brown hare diet in relation to food availability, and dietary overlaps with several herbivores in northern Patagonia. Food availability was estimated by point-quadrat transects, and hare diet by microhistological analysis of faeces, carried out in five habitats in five seasonal samplings. Significant differences were detected by Kruskall–Wallis ANOVA with multiple comparisons by Tukey test. Feeding selection was detected by χ² test, and dietary preferences by the confidence interval of Bailey. Grasses and chamaephytes were the most available plant categories, with Stipa, Panicum and Acantholippia as main species. Grasses and phanerophytes were the main dietary categories, including Poa, Panicum, Bromus, Adesmia and Prosopidastrum. The phanerophytes Prosopidastrum and Ephedra were more eaten in winter, when the main food item (Poa) presented lower availability. A higher dietary proportion of the chamaephyte Acantholippia occurred in rocky habitats, where the coarse dominant grasses were always avoided. Hares shared most food items with several wild and domestic herbivores in northern Patagonia. The lack of preference for forbs differentiates brown hares from other herbivores. However, hares exhibited important dietary similarities with plain and mountain vizcachas, goats and horses, and an interspecific competition for food is highly probable.     

Seasonal Food Use Strategies of <Emphasis Type="Italic">Semnopithecus vetulus nestor</Emphasis>, at Panadura and Piliyandala,Sri Lanka

Field studies on Semnopithecus vetulus have shown high folivory and the ability to feed heavily on mature leaves, which are constantly available. In research spanning 19 mo, I examined the feeding behavior of 2 free-ranging groups of Semnopithecus vetulus nestor in home gardens and rubber monocultures at Panadura (PT1 group) and Piliyandala (R1 group), Sri Lanka. Overall, results showed that >80% of their diet comprised seasonal plant parts, largely fruits. Despite differences in spatial and temporal food availability in their respective habitats, seasonal plant parts dominated the diets of both groups except briefly (2 mo) for R1 when mature leaf petioles were the main plant food. Both groups increased their use of seasonal foods with heightened seasonal food availability, and increased dietary diversity with declining use of their highest-ranked specific item of diet: fruits of Artocarpus heterophyllus (jakfruit, Moraceae). PT1, which was in a species-rich environment, maintained a high intake of seasonal foods year round by exploiting a large number of species, mainly for fruits. In contrast, R1, in a habitat with significantly lower tree species richness, had a less diverse diet but maintained an equally high intake of seasonal foods, primarily fruits and seeds, by exploiting a few species heavily. My study also highlights the dietary flexibility of a single colobine species in space and time. Such information is useful for conservation planning because rapidly occurring changes are taking place in natural colobine habitats.     

Diets of two sympatric colobines in Zaire: More evidence on seed-eating in forests on poor soils

Recent studies have shown that the so- called folivorous African colobines eat a significant amount of seeds. There is disagreement as to whether seed-eating is due to the poor quality of tree foliage, due in turn to poor soils, or to the fact that seeds are a normal part of colobine diets. To test these hypotheses, we studied feeding of red colobus monkeys, Colobus badius tholloni,and black-and-white colobus monkeys, Colobus angolensis angolensis,in a tropical rain forest of Central Zaire (Salonga National Park). We conducted studies on soil properties, vegetation composition, and the availability and chemical contents of food plants simultaneously. Soils were very acid, with a high percentage of sand, very low cation exchange capacity, and very low exchangeable bases. The forest was dominated by legumes (45.6% of trees), among which the Caesalpinioideae were the best represented (85%). C. badiusfed mostly on leaves (61%) and seeds (33%), legumes making up 65% of their diet. C. angolensisfed mostly on seeds (50%) and leaves (27%); 39% of their diet came from legumes. The two species tended to select items richer in crude protein or lipids or both. Total phenolics and condensed tannins were abundant in the foliage and seeds but were poor predictors of colobine choice of food. Intersite comparisons show that colobines in Zaire ate a higher proportion of seeds than all other related species so far studied in Africa and that the Salonga forest had among the poorest soils and harbored the highest percentage of Caesalpinioideae. Our results confirm that seed- eating is more common among colobines living in areas where soils are poor. They strongly suggest that this link is mediated through forest composition, especially the abundance of legumes, and that the development of seed- eating results both from the high availability of nutrient-rich seeds and from the poor quality of mature tree foliage.