Feeding habits of chimpanzees (Pan troglodytes), red-tail monkeys (Cercopithecus ascanius schmidti) and blue monkeys (Cercopithecus mitis stuhlmanii) on figs in Budongo Forest Reserve, Uganda

Feeding habits of chimpanzees, red‐tail and blue monkeys on figs (Ficus) were studied in compartment N3 of Budongo Forest Reserve, western Uganda, from September 1997 to March 1998. The aim was to examine the spatial and temporal foraging habits of chimpanzees, red‐tail monkeys and blue monkeys on figs in the forest reserve. Both scan and focal sampling methods were used to assess the foraging habits of the primates. It was found that the primates fed on emerging leaves of Ficus mucuso Ficalho, F. varifolia Warb. and F. exasperata Vahl. They also preferred ripe fruits to emerging, young and unripe fruits. The primates spent 78% of the morning eating fruits and leaves and inhabited fig trees with fruits for about 4 h. Fig trees with ripe fruits attracted larger numbers of primate groups. It is concluded that information on the feeding habits of chimpanzees and monkeys is required in order to have a clear understanding of the social behaviour and pattern of movement of the primates and to assist in predicting the likely impacts of poor forest management, forest degradation and loss of food resources on their populations.     

Behavioral ecology ofAlouatta seniculus in Andean cloud forest

The behavior and ecology ofAlouatta palliate àre well studied; we report here on the first long-term study of anotherAlouatta species, the red howler monkey,A. seniculus. AlthoughA. seniculus was studied at a high elevation in the Colombian Andes, it exhibits many behavioral and ecological similarities to lowlandA. palliata. Continuous focal sampling indicates thatA. seniculus spends 78.5% of its time resting, 5.6% moving, and 12.7% feeding. It has a day range of 1.09 km and a home range of 22 ha. Like its more northern relative,A. seniculus spends more than 50% of its feeding time on leaves–especially young leaves–but on a dry-weight basis, fruits comprise the majority of its diet. The small home and day ranges observed as well as the large amounts of time spent resting are all argued to be aspects of a relatively folivorous foraging strategy. Daily food intake is estimated to be 1.23 kg fresh weight (0.266 kg dry weight). Foraging efficiency (yield/time) varies by a factor of almost 6 across major food types, with item size and distribution being the key determinants. Food preferences change markedly over the activity period, with high-energy sources predominating early and high-protein sources late.     

A preliminary study of food selection by the orangutan in relation to plant quality

We observed the foraging behavior of orangutans in Central Indonesian Borneo during October, November, and December 1980, and analyzed food and nonfood items for water content, neutral detergent fiber, crude protein, available crude protein, and protein:fiber ratio and the presence of alkaloids and tannins. The diet of the orangutan during this season was unusual because it consisted predominantly of seeds and unripe, rather than ripe, fruits. Also, the major diet item, the seeds ofIrvingia malayana, had been ignored in previous years when it had fruited. In leaves, protein content was more closely associated with food choice than either neutral detergent fiber or the protein:fiber ratio. Flowers had the highest protein content and protein:fiber ratio of any food item. Tannins were found in most food items, but the presence of alkaloids was found in only one.     

A test of non‐kin social foraging in the southern flying squirrel (Glaucomys volans)

It can be challenging to understand the evolution of sociality, particularly the occurrence of co‐operation by non‐kin. Southern flying squirrels (Glaucomys volans) are an interesting example of non‐kin co‐operation because of the mutual benefits obtained by social thermoregulation during winter. Because group survival confers benefits to the entire group, flying squirrels may also follow an aggregation economy, whereby co‐operative foraging during winter is advantageous. However, the extent of such social foraging in flying squirrels is unknown. We tested for social foraging of southern flying squirrels, and also for relatedness among foraging groups. To determine the structure of foraging groups, we set up and remotely monitored feeding stations and nest cavities. All squirrels at the study site were tagged with passive integrated transponder (PIT) tags and nests and feeding stations were monitored with automated PIT‐tag recorders for a 24‐month period. Squirrels were found most often foraging alone. Squirrels that were recorded foraging together comprised unrelated individuals that were also found to share nest cavities. Squirrels were also recorded travelling farther distances between nest cavity and feeding station in the winter season than in the summer season, suggesting that, during winter, squirrels trade‐off proximity to food caches for membership in a nest group. Our data suggest that squirrels forage and cache alone in their summer home range and make solitary returns to this summer range to collect their cache during the winter months, despite exhibiting social winter nesting. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 113 , 1126–1135.     

Climatic determinants of diet and foraging behaviour in baboons

Baboons (Papio spp.) are characterised by a large degree of variation in foraging behaviour and dietary composition. Previous analyses have suggested that much of this can be traced to differences in ecological conditions between sites. The proximate mechanism underlying these relationships is assumed to be mediated via the impact of climatic conditions on food availability, and ultimately the impact that this has on dietary composition. This paper examines these relationships more explicitly. Data from 15 baboon populations were used to assess the relationship between foraging variables and dietary composition. Only feeding time showed significant relationships with dietary composition, with percentage of time spent feeding decreasing with proportion of fruit in the diet, and increasing with the proportion of subterranean items. No relationships were found between diet composition and moving time or day journey length, although significant relationships were found between these variables and group size. The proportions of feeding time spent feeding on fruit, subterranean items and leaves were functions of the ecological conditions experienced by that population, although no relationships were found for the percentage of feeding time devoted to flowers or animal material. The relationships between the proportion feeding time spent on fruits, leaves and subterranean items and ecological variables could be best explained through understanding the way in which bush and tree level vegetation respond to the climatic environment and the impact this has on fruit availability. In this respect, temperature and seasonality are the key climatic parameters. This provides good support for the idea that the proximate mechanism underlying the relationship between foraging time and ecological variables is mediated via the impact of the climatic environment on vegetation structure and food availability. Similar factors have been proposed to explain much of the geographic variation in species diversity, suggesting that these relationships have far wider relevance and may account for much of the observed geographical variation in mammalian behaviour.     

Haliotis tuberculata,a generalist marine herbivore that prefers a mixed diet,but with consistent individual foraging activity

While population foraging behaviour of herbivores has been extensively studied, individual choice is still poorly understood. Very few studies have focused on the individual consistency of foraging behaviour in marine herbivores. Because marine ectotherms are strongly influenced by their environment and because a mixed diet is appropriate for herbivores, we hypothesized that Haliotis tuberculata, a large marine gastropod, would not exhibit significant individual consistency in foraging activity and would display generalist food choices. To test these hypotheses, the behaviour of 120 abalone was studied using a choice test of eight macroalgal species over 3 weeks, with video recording 24 hr a day. In addition, primary components, secondary metabolites and toughness of the eight algae were measured. At the population level, food choice was mainly related to the protein composition and the toughness of the macroalgae. We found that H. tuberculata is a generalist species feeding on a variety of algae (IS = 0.64), even if 21% of the individuals can be considered to be specialists. However, in contrast to our hypothesis, highly consistent between-individual variation was observed in foraging activity (ICC = 0.81 for time spent feeding and ICC = 0.74 for number of feeding visits per day). The high individual consistency of foraging activity has some ecological and evolutionary implications currently not understood for this marine herbivore.     

Feeding ecology and foraging behaviour of impala Aepyceros melampus in Lake Mburo National Park, Uganda

Intersexual and seasonal variation in foraging behaviour of impala (Aepyceros melampus), was studied in the Lake Mburo National Park, Uganda. There was a moderate seasonal difference in foraging efficiency (as measured by ‘acceptable food abundance’), with a minimum in dry season and a maximum in Rainy season. The variation between sexes was more distinct with a pronounced minimum in time spent browsing of males in early wet season. By distinguishing between feeding time spent grazing and feeding time spent browsing the seasonal variation was confirmed. The proportion of foraging time spent feeding (expressed as ‘food ingestion rate’) showed an inverse pattern with a maximum in the late dry season (75.5%), decreasing values throughout the Rainy season and a minimum in early dry season (57.8%). Differences between sexes were explained in terms of reproductive demands and seasonal balance in terms of moderate climate throughout the year. Impala foraging patterns in the bimodal tropics (two Rainy seasons) is discussed and compared with unimodal tropics. The findings are matched against current ideas on optimal foraging.     

Lion-tailed macaques (Macaca silenus) in a disturbed forest fragment: Activity patterns and time budget

We describe the activity patterns and time budget of a feral group of lion-tailed macaques that were confined to a disturbed forest fragment of 65 ha and compare the results with those obtained for groups in protected forests. The degraded nature of the study site was reflected in low tree densities, low specific diversity, gaps in the girth distribution of trees, and frequent disturbance by humans. The study group of 43 subjects was twice as large as lion-tailed macaque groups in protected habitats. They spent the most time ranging (34.0%), followed by foraging (23.7%), feeding (17.9%), resting (16.0%), and other activities such as social interactions (8.4%). Monthly variations are significant for all activity categories except ranging. Times spent resting and foraging are negatively correlated (r = −0.5) and show significant seasonal differences. Foraging time was highest from September to November, when key food sources such asCullenia andArtocarpus were absent or marginally available. The study group spent most time (40.4%) at canopy levels between 21 and 30 m. They spent more time each day ranging than resting or feeding and more time terrestrially compared with groups in protected forests. Large group size, poor habitat quality, and seasonal variation in food availability were the major variables affecting their time budget, and these variables accounted for differences from the time budgets of groups in protected forests.     

Arboreal locomotor and postural behaviour of European red squirrels (<Emphasis Type="Italic">Sciurus vulgaris</Emphasis> L.) in northern Greece

The study of the locomotion and postures of arboreal squirrels may provide important contextual information on the evolution of the morphology and ecology of sciurids. In this context, we studied the positional behaviour and habitat use of four adult European red squirrels (Sciurus vulgaris L.) in a mixed coniferous forest in northern Greece. Our results show that, during the study period, S. vulgaris extensively used the forest canopy and the terminal branch zone. The use of small and medium supports of all orientations was also particularly frequent. The positional profile of the species was characterized by the dominance of quadrupedal, clawed and airborne locomotion along with seated and standing postures. Quadrupedalism and sitting appeared to promote terminal branch use for food access and manipulation, while claw climbing favored vertical ranging and retreat to trees after terrestrial foraging. Finally, leaping reduced energetic costs during travelling between food sites within the relatively dispersed forest. These results and those of previous research on the positional behaviour of other squirrels reveal several trends related to body size, arboreal or gliding habits and tropical or temperate forest distribution and contribute to the understanding of evolutionary novelty in multiple levels within the sciurid radiation.     

Removal of palm fruits and ecosystem engineering in palm stands by white-lipped peccaries (Tayassu pecari) and other frugivores in an isolated Atlantic Forest fragment

Long-term studies in a 2,178 ha fragment of semideciduous Atlantic Forest demonstrated important interactions between white-lipped peccaries (Tayassu pecari) and the common palms, Syagrus romanzoffiana and Euterpe edulis. We conducted fruit removal and medium-to-large-sized mammalian exclusion experiments to: (1) quantify seasonal fruit consumption from high-density patches beneath parent trees by T. pecari and other consumers, and (2) measure impacts of T. pecari rooting and foraging activities on seedling dynamics in E. edulis stands. A diverse array of fauna consumed S. romanzoffiana fruits. During the dry season, when S. romanzoffiana palms provided 68% of fruit dry weight in the fragment, T. pecari consumed significantly greater amounts than other consumers, and along with Pecari tajacu and Tapirus terrestris, were potential seed dispersers. The rodents, Sciurus ingrami and Agouti paca, consumed most S. romanzoffiana fruits in the wet season, acting as both seed dispersers and predators. More than 95% of E. edulis fruit removal was due to seed predation by T. pecari. Intense removal during the dry season was closely linked with previously documented range shifts and habitat preferences by T. pecari. Exclusion plot experiments in E. edulis (palmito) stands showed that the number and proportion of nonpalmito (not E. edulis) seedlings increased dramatically in the absence of T. pecari rooting and foraging activities that disturbed soil and thinned seedlings. We discuss the importance of these ecosystem engineering activities and palm-peccary trophic interactions for long-term maintenance of E. edulis stands and T. pecari populations, as well as water balance, in the forest fragment.     

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.     

Variability in the area,energy and time costs of wintering waders responding to disturbance

Birds’ responses to human disturbance are interesting due to their similarities to anti‐predator behaviour, and understanding this behaviour has practical applications for conservation management by informing measures such as buffer zones to protect priority species. To understand better the costs of disturbance and whether it will impact on population size, studies should quantify time‐related responses as well as the more commonly reported flight initiation distance (FID). Using waders wintering on an estuarine area, we experimentally disturbed foraging birds on the Wash Embayment, UK, by walking towards them and recording their responses (FID, alert time, time spent in flight, time taken to resume feeding, and total feeding time lost). We present data for 10 species of conservation concern: Curlew Numenius arquata, Oystercatcher Haematopus ostralegus, Bar‐tailed Godwit Limosa lapponica, Grey Plover Pluvialis squatarola, Redshank Tringa totanus, Knot Calidris canutus, Turnstone Arenaria interpres, Ringed Plover Charadrius hiaticula, Sanderling Calidris alba and Dunlin Calidris alpina. Larger species responded more strongly, response magnitude was greater under milder environmental conditions, and responses varied over both small and large spatial scales. The energetic costs of individual responses, however, were low relative to daily requirements and disturbance events were unlikely to be frequent enough to seriously limit foraging time. We suggest, therefore, that wintering wader populations on the Wash are not currently significantly negatively impacted by human disturbance during the intertidal foraging period. This is also likely to be the case at other estuarine sites with comparable access levels, visitor patterns, invertebrate food availability and environmental conditions.     

Fire induced changes in the foraging behaviour of impala Aepyceros melampus in Lake Mburo National Park, Uganda

The impact of fire on the foraging behaviour of impala (Aepyceros melampus), was studied in the Lake Mburo National Park, Uganda. Two indices of foraging efficiency were used to establish differences in feeding behaviour in burnt and unburnt control areas. These are acceptable grass/browse abundance (AGA/ABA), expressed in terms of feeding time achieved per 50 steps and food ingestion rate (FIR), expressed as the cumulative percentage. Accumulation of above ground grass biomass was also measured in burnt and control areas. After burning, the grazing efficiency remains constant throughout the dry season, while the browsing time achieved per 50 steps decreases drastically. In the control areas AGA decreased with increasing length of the dry season while ABA increased. When expressed in terms of cumulative percentage (FIR), the results show a significant increase of 31% in foraging time spent grazing and a 24% decrease in foraging time spent browsing, in burnt areas. The results confirm the classification of impalas as intermediate or mixed feeders with a distinct preference for grass. Impala foraging patterns after burning are discussed and compared with investigations on the effect of burning on the behaviour of impalas and Buffon's kob (Kobus kob kob) in other areas of Africa.     

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.     

LETTERS TO THE EDITOR

Cox, George W. 1983. Foraging behaviour of the Dune Lark. Ostrich 54:113-120.

Foraging behaviour of the Dune Lark Mirafra erythrochlamys was studied in a dune environment at the Namib Research Institute, Gobabeb, South West Africa/Namibia in August 1981. Birds foraged for a total of 7 h per day in morning and afternoon periods separated by 3 h of inactivity during the warm midday. The birds exploited a distinctive series of vegetational belts dominated by three grasses. About two-thirds of total foraging time was spent in zones of dead and dormant grasses where seeds were sought by excavating small craters in the sand with the bill. Simples taken in the field, and simulations of bill-cratering behaviour in the laboratory, showed that this behaviour displaced seed-poor surface sand and exposed deeper, seed-rich layers. Birds formed small flocks when foraging for seeds in these zones. The remaining third of foraging time was spent in zones with large, live grass clumps, where insects were sought. Insect foraging was concentrated at the start and end of each activity period, but was most intense just before the midday period of inactivity when temperatures approached 30°C. Rough calculations of energy and water balance suggest that the larks are unable to maintain water balance under the observed conditions on seed food alone, and that this balance is achieved by feeding on insects. It is predicted that relative seed and insect foraging effort varies with temperature and season, as also suggested by limited published data on stomach contents in summer and winter.     

Diet and feeding ecology of gray woolly monkeys (lagothrix lagotricha cana) in Central Amazonia: Comparisons with other Atelines

I studied gray woolly monkeys (Lagothrix lagotricha cana)in an undisturbed central Amazonian terra firme forest, near the headwaters of the Urucu river, Tefé, Amazonas, Brazil (5°50’S, 65°16’W). I report the diet and feeding ecology of a group of 39–41 individuals, based on systematic feeding observations obtained during 11 months. Woolly monkeys are primarily frugivorous; mature fruits and young seeds account for 83 and 7% of 3298 feeding records, respectively. On a seasonal basis, however, they relied heavily on young foliage (16%), seed-pod exudates (6%), and flowers (3%), particularly during the greatest annual period of ripe fruit scarcity, as determined by a phenological survey. Animals represent only 0.1% of their year-round diet, and they spent little time capturing arthropods and other prey items. Although at least 225 plant species, belonging to 116 genera and 48 families, are in their diet, the three top-ranking families (Moraceae, Sapotaceae, and Leguminosae) account for 43% of their food species and 63% of the time they spent feeding on a year-round basis. I compare the feeding ecology and diet of L. 1. canain the Urucu and other taxa of Lagothrixin upper Amazonia — the last large-bodied Neotropical primates to be studied — to those of other ateline genera: Atelesand Brachyteles. An erratum to this article is available at .     

Activity budget and foraging behaviour of red squirrels (Sciurus vulgaris) in coniferous and deciduous habitats

Activity pattern, activity budget and foraging behaviour are compared between radiotagged squirrels in a coniferous and a deciduous habitat. Differences between habitats are explained in terms of differences in food availability, food choice and feeding rate.     

Underwater observations of piranhas in western Brazil

Synopsis The behaviour of three piranha species,Serrasalmus marginatus, S. spilopleura, andPygocentrus nattereri, and their prey fishes was studied underwater in the Pantanal region, Mato Grosso, Brazil. General habits, predatory tactics, feeding behaviour, and social interactions while foraging, as well as defensive tactics of prey fishes were observed.S. marginatus is solitary whereas the other two species live in shoals; their agonistic behaviour varies accordingly, the simplest being displayed by the solitary species. Predatory tactics and feeding behaviour also vary:S. spilopleura shows the most varied diet and highly opportunistic feeding strategy, which includes aggressive mimicry. The solitaryS. marginatus, besides fin and scale-eating, occasionally cleans larger individuals ofP. nattereri. Several cichlid species display defensive tactics clearly related to piranha attacks: tail protecting, watching, and confronting the predator are the most commonly observed behaviours. Piranhas seem to strongly influence use of habitat, social structure, and foraging mode of the fish communities.     

Feeding ecology and activity pattern of black-fronted titi monkeys (<Emphasis Type="Italic">Callicebus nigrifrons</Emphasis>) in a semideciduous tropical forest of southern Brazil

Most aspects of the ecology and behavior of Callicebus nigrifrons are still unknown. The information available about this species is mainly based on a few studies that also focused on other Callicebus. We examined the feeding behavior and activity pattern of a free-ranging pair of C. nigrifrons between March and November 2007 in an area of semideciduous tropical forest of southeastern Brazil. The study site is located at the southern limit of the Tropical Zone and is characterized by pronounced seasonality. As observed for other Callicebus monkeys, fruits were the most consumed food resource, accounting for 53% of the diet, which was complemented mainly by leaves (16%) but also by invertebrates and flowers (10% of each). A great variety of plant families (28) and species (62) were included in the diet. The titis spent 35% of their time feeding, distributing the remaining time between resting (30%) and traveling (24%). Data presented here indicate that C. nigrifrons prefer high-quality food items (fruit pulp), adding low-quality food items (such as leaves) as the availability of the higher-quality foods decreases. The amount of time spent traveling and resting did not change between seasons, but the time invested in feeding increased during the lean period. The activity pattern was not related to fruit availability, but in months with lower temperatures, monkeys spent more time feeding. We suggest that the feeding ecology and activity pattern of C. nigrifrons reflect adaptations related to annual fluctuations in food availability and temperature, respectively.