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The Socioecological Basis for the Conservation of the Toque Monkey (Macaca sinica) of Sri Lanka (Ceylon)
... Much of the flora and fauna are diversified according to phytoclimatic zones. The nonhuman primates, for example, occur as 3 genera, 5 species, and 12 subspecies (ssp.): 2 species of loris Loris tardigradus (1 ssp.) and L. lydekkerianus grandis (3 spp.), 1 gray langur Semnopitheus priam (1 monotypic spp.) that is confined to the low and midland Dry Zone, 1 purple-faced langur S. vetulus (4 ssp.) that is most prevalent in the wet and moist habitats at all elevations, and the toque macaque Macaca sinica (3 ssp.), which occurs in all habitats where monkeys have access to open water [Dittus, 1977a]. Three species and all subspecies are endemic. ...
... The gray langur, whose distribution is confined to the Dry Zone, has been assessed regarding HMC issues [Unanthanna and Wickramasinghe, 2010;Dittus et al., 2019]. Conservation and HMC focusing on the toque macaques have been reviewed by Dittus [1977aDittus [ , 2012a and by Nahallage and Huffman [2013]. Comprehensive comparisons of HMC issues involving all diurnal species of Sri Lankan primates at different geographical locations, but particularly in the central and southern regions of the island, have been considered by Nahallage et al. [2008], Cabral et al. [2018a and by Rudran et al. [2021]. ...
... The distribution of primates in these vast dry areas tends to be confined to the narrow belts of riparian forests where plant diversity and productivity are comparatively benign [Hladik and Hladik, 1972]. Fortunately, some newly established National Parks in the Dry Zone (since 1997) have added moister forests where primate densities are estimates as moderate [Dittus, 1977a]. Protected areas in the lowland, midland, and highland rain forests areas are the most restricted in size (<5% of protected areas) and threats of extinction are high outside of these refugia; for example, 60% of all mammal taxa are threatened in the low and midland rain forest regions [Dittus, 2018]. ...
Many investigators of human-monkey competition (HMC) in Sri Lanka have revealed some common threads. Except at temple and protected sites, all monkeys were considered as household or agricultural pests wherever they shared space with humans. This included the widely distributed toque macaque (Macaca sinica), the grey langur (Semnopithecus priam thersites) of the Dry Zone, and the purple-faced langur (S. vetulus) of the southwestern and central rain forests where human densities and habitat fragmentation were greatest. People sharing space with monkeys resorted to various non-lethal methods to chase monkeys away from their properties and most preferred to have monkeys removed to protected areas; such translocations have been politically popular, though contrary to ecological principles. The main cause of HMC near primate habitats has been environmental conversion to agriculture, whereas in many towns the refuse generated in the wake of widespread growing tourism lured omnivorous macaques towards human habitation and stimulated macaque population growth. While most Sri Lankans share space with monkeys reluctantly, only a minority, flouting cultural restraints, want monkeys destroyed. Nonetheless, a major threat to primate conservation has been habitat loss and the killing of monkeys, especially in the densely populated southwestern area of the island where recent surveys showed that most macaques have been wiped out. Two subspecies, S. v. nestor of the rain forest lowlands and M. s. opisthomelas of the montane forests, are Critically Endangered. Sharing space with monkeys rests on public tolerance, understanding, and empathy with monkeys. Religious concepts venerating monkeys provide fertile ground for this. Our science-based educational documentaries (n > 35), among other efforts, also have contributed to these human sentiments in Sri Lanka and globally. The trends in HMC suggest that protected nature reserves for all wildlife are more secure for primate survival than ethnoprimatology by itself would be. Rudran [Folia Primatologica 2021, DOI: 10.1159/000517176] criticized our recent publication on HMC in Sri Lanka [Dittus et al., Folia Primatologica 2019, 90: 89-108]. We consider his comments as misconstruing efforts in primate conservation through denying the importance of traditional protected areas, overlooking our achievements in educating the public and reducing HMC, as well as misunderstanding the limits of marketing monkeys to tourists as a source of income to support conservation.
... Although the majority of the rain in the Wet Zone comes between May and October, as a result of the southwest monsoon, there is no real dry season. By contrast, the northern Dry Zone of the island faces regular periods of drought between May and September (Mueller-Dombois, 1968;Dittus, 1977). The position of these boundaries in the past is relatively poorly understood, however, with well-dated palynological information coming from only the Horton Plains in the highlands of Sri Lanka (Premathilake and Risberg, 2003;Premathilake, 2012). ...
... Trachypithecus vetulus has lower d 13 C values than M. sinica at the site of Fa Hien-lena. Given what we know about the digestive tract of the former (Hladik, 1977) and generalist diet of the latter (Dittus, 1977), this could be linked to an increased focus on leaf consumption in T. vetulus versus M. sinica (SOM Table S7) (see also Roberts et al., 2017, accepted in press). At the Polonnaruwa Nature Sanctuary and Archaeological Reserve in northern Sri Lanka, where all three species are sympatric, long-term observational data demonstrate that T. vetulus is a specialised folivore, obtaining 70% of its food from the mature leaves of three species (Hladik, 1977). ...
... Semnopithecus p. thersites, in contrast, obtains~70% of its food from 10 tree species, including in its diet 48% leaves, 7% flowers, and 45% fruits by wet weight (Hladik, 1977). The generalist M. sinica exploited 89% of the 46 species of trees within the Reserve, with fruits constituting over 70% of their diet, alongside flowers, leaves, mushrooms, fungi, grasses, roots, tubers, resins and invertebrates (Dittus, 1977). What is of greater interest is the fact that this supposedly specialised folivore, T. vetulus, is making use of more varied and more open habitats at Batadomba-lena (d 13 C range ¼ À17.0 to À10.9‰) and Bellan-bandi Palassa (d 13 C range ¼ À14.8 to À9.5‰), respectively, relative to the apparently focused, closed canopy diets of this species at Fa Hien-lena (À17.8 to À14.1‰; À16.3 ± 1.0‰). ...
... Preformed water in the foods of freeranging nonhuman primates has been reported to vary from less than 5% of air-dried seeds in hot deserts to over 70% of the fresh weight of succulent plant parts in tropical rainforests (Baranga, 1982;Calvert, 1985;Rogers et al., 1990;Barton et al., 1993;Robbins, 1993;Edwards, 1995). Many of these species, thus, often lick dew and rainwater from leaves in the early morning or after rainfall, only rarely descending to the ground to drink (e.g., Presbytis [currently Trachypithecus] johnii, Poirier, 1970; Macaca sinica, Dittus, 1977;Cebus albifrons, Defler, 1979; Procolobus badius temminckii, Starin, 2002). Another source, more difficult to observe and thus, perhaps less frequently reported, is the drinking of rainwater accumulated in the holes of tree trunks (but see Dittus, 1977;Glander, 1978;Chapman, 1988;Starin, 2002). ...
... Many of these species, thus, often lick dew and rainwater from leaves in the early morning or after rainfall, only rarely descending to the ground to drink (e.g., Presbytis [currently Trachypithecus] johnii, Poirier, 1970; Macaca sinica, Dittus, 1977;Cebus albifrons, Defler, 1979; Procolobus badius temminckii, Starin, 2002). Another source, more difficult to observe and thus, perhaps less frequently reported, is the drinking of rainwater accumulated in the holes of tree trunks (but see Dittus, 1977;Glander, 1978;Chapman, 1988;Starin, 2002). ...
... We believe that the drinking water from holes in trees might be more prevalent than previously thought, given the wide range of species and habitats represented in this preliminary investigation. While such behavioural strategies may be of relatively rare occurrence in most primate populations, more systematic observations are required to accurately ascertain the frequency and significance of these strategies for particular populations or individuals (see, for example, Dittus, 1977). We hope that this report will stimulate similar research in other primate species and further discussions on the possible functions of these unusual behaviours for the health and general survival of primate populations and their individual members. ...
... The study population of macaques initially involved about 450 individuals that were distributed among 18 independent social groups [Dittus, 1977a]. Some of these groups had increased their numbers over the years, split into two or more daughter groups, a few became extinct, and new groups (of demographic and ecological interest) also were added to the original population sample [Dittus, 1988;Dittus et al., 2019]. ...
... Toque macaques are long-tailed and anatomically adapted to move through the trees and on the ground [Grand, 1972[Grand, , 1976. They forage, rest, and sleep in the trees and come to the ground mostly to forage when food sources are most accessible at ground level [Dittus, 1977a]. They do not normally climb up transmission posts or contact electrical wires at the study site. ...
When monkeys, such as the toque macaques (Macaca sinica) of Sri Lanka, seek food on the ground near human habitation, they may use electrical posts to escape aggression from conspecifics, dogs, or humans. Shields mounted on electrical posts prevented monkeys from reaching the electrical wires, thereby averting their electrocution: the frequency of electrocutions (n = 0) was significantly less (p < 0.001) in the 12 years after installation of the shields than in the 12 years before (n = 18). Electric shocks were either fatal (n = 14) or caused permanent injury (n = 4) (collectively referred to as electrocutions hereafter). The shields may find broader applications in other primate species and environments wherever monkeys are attracted by human food near electrical posts. Primates and other arboreal mammals also accessed live wires from trees; at known electrocution hotspots, short spans of exposed wires were insulated by encapsulating them in PVC water pipes. It was impossible, however, to prevent electrocutions from all electric supply infrastructures that put monkeys at risk. A wider use of insulated electric conductors in planning power distribution in habitats frequented by wild animals would be desirable in preventing electric shocks to wildlife.
... individuals per km 2 . This contrasts starkly with the density of macaques (50-100 individuals per km 2 ) or langurs (150-200 individuals per km 2 ) in well-watered productive sites such as Polonnaruwa or in riverine forest (Dittus, 1977b). ...
... For 40 years biologists have been flagging the importance of preserving the rainforests rich in endemism and biodiversity (e.g, Crusz, 1973;Dittus, 1977b;Senanayake et al., 1977;Gunatilleke and Gunatilleke, 1983), and the same applies to rich habitats in the dry zone (Eisenberg and Lockhart, 1972;McKay, 1973). Governments decide on land use for the common good: roads, highways, schools, agricultural schemes, housing developments and commercial properties. ...
All mammals originated on the supercontinent of Pangaea in the Mesozoic era during the “Age of Reptiles.” However, the crown ancestors of contemporary mammals did not flourish until major environmental and biotic changes had occurred. An asteroid collided with earth at the end of the Cretaceous Period (the K-Pg boundary event) wiping out non-flying dinosaurs and primitive mammals. It was followed by large-scale volcanism, a spike in atmospheric oxygen and the proliferation of flowering plants. New niches became available for the ancestors of today’s mammals to fill. Evidence suggesting whether the ancestors of the Sri Lankan and Indian mammals originated on the tectonically marooned Indian plate before crashing into Asia or on the Laurasian supercontinent is inconclusive. Modern Sri Lankan mammals show their greatest affinity with those of southern India, and were more diverse in the Pleistocene when rhinoceros, hippopotamus, wild dogs, gaur and lions enriched the island’s landscapes. Native Sri Lankan land-based mammals are diversified into about 108 unique taxa (among 91 species and 53 genera), differentiated as phenotypic adaptations to sharply contrasting environments among seven major phyto-climatic zones. Endemic subspecies are distributed fairly equally across different phyto-climatic zones (n=24 to 29), except in the highlands where they are fewer (n=14) having evolved rapidly to species and genera among the insectivores and rodents whose reproductive rates are high. Conversely, greater numbers of endemic species (n=13) and genera (n=3) occur in the highlands than in the other zones (2-6 endemic species, no endemic genera). The prevalence of endemism is inversely related to body size or vagility. This suggests a greater probability of genetic exchange among distant populations of large bodied mobile mammals within Sri Lanka, as well as with Indian fauna during periods of land bridges in the Pleistocene. Most (8 of 13) endangered and critically endangered endemic mammals occur in the wet montane regions that offer the least Protected Areas (PAs). More than 85% of PAs occur in the extensive dry zone about half of which is not suited for water dependent mammals whose distributions are restricted to alluvial forests (less than 1% of PAs). Historically, the national cost of conservation has been low and therefore politically palatable. Current conservation urgently requires a major change in management policy combined with realistic investment to prevent extinctions of many endemic mammals and other unique Sri Lankan biota.
... Although prone to climatic variation, S. U. Deraniyagala emphasised the large concentrations of medium-sized ungulate fauna available across the Dry Zone (Phillips, 1980), with spotted deer and hare being the most abundant (Eisenberg and Lockhart, 1972). Other faunal resources include cervids (sambhur, mouse-deer, barking deer), bovids (buffalo), the giant squirrel, monkeys (gray langur, toque macaque), elephant, and wild boar (Bambaradeniya, 2006;Dittus, 1977;Eisenberg and Lockhart, 1972). Also present are diverse reptiles (e.g., hard and soft-shelled terrapins, star tortoise, python, ratsnake, land monitor, crocodile), fish (e.g., snakehead, catfish, eels), and bird communities (Eisenberg and Lockhart 1972;Nyrop et al. 1971). ...
Over the last three decades, Sri Lanka has risen to international prominence as a key area for exploring past forager adaptations. Much of this discussion has focused on the lowland rainforests of the Wet Zone of the island, and their preservation of the earliest fossils of our species, bone tools, and microlithic technologies in the region ca. 45,000 years ago. It has been recognized that the northern and southern coasts of Sri Lanka represent crucial locales for studying human occupation and adaptation through the Pleistocene and Holocene. Here, we revisit the important shell midden site of Mini-athiliya (dating to ca. 4,000 cal. years BP), on the southern coast of Sri Lanka, which has yielded human remains alongside microlithic stone tools and animal remains. We present a comparative analysis of body size variation of the human remains belonging to the HMA 6 adult skeleton from Mini-athiliya with a wider database of foragers to investigate local adaptations. We also apply stable carbon and oxygen isotope analysis to the tooth enamel of four other individuals documented at Mini-athiliya in order to determine their dietary reliance on forest, grassland, or coastal resources. Together, our results highlight that, rather than a clear distinction between earlier forest adaptations and later coastal specialisation, the Mini-athiliya individuals provide evidence for a plastic spectrum of ecological adaptation. We argue for continued research on how human populations in different parts of the island interacted and adapted to its diverse tropical settings across space and time.
... s. aurifrons, Pocock, 1931) in the rainforests of the lowland and midland of the wet zone, and the hill-zone macaque (M. s. opisthomelas, Hill, 1942) in the montane regions (Dittus, 1977;Nekaris and de Silva Wijeyeratne, 2009;Dittus, 2013) (Fig. 1). ...
Understanding variations in host-parasite relationships with urbanization is vital for both, public health management and conservation of endemic animals with high anthropogenic interactions. Toque macaques (Macaca sinica) are such endemic old-world monkeys in Sri Lanka. Three macaque sub species inhabit the main climatic zones of the island; M. s. sinica, M. s. aurifrons and M. s. opisthomelas inhabit the dry zone, wet zone, and montane regions of the island, respectively. This study aimed to examine parasite prevalence in this host in association with urbanization. A total of 180 fecal samples were collected from the three sub species of toque macaques inhabiting the main climatic zones (dry, wet, and montane) in Sri Lanka; 20 samples each were collected from urban, suburban, and wild populations representing each climatic zone. Twenty gastrointestinal (GI) parasite genera types i.e. five types of protozoan cysts, two types of trematode ova, four types of cestode ova, eight types of nematode ova, and a single type of acanthocephalan ova were identified. The overall prevalence of parasites was 62% (112/180) with the highest prevalence of Strongyloides infection. In all three sub species, toque macaque populations with proximity to human settlements, including urban and suburban populations, manifested a greater GI parasitic prevalence, mean ova/cyst counts and species richness, compared to their wild counterparts. Importantly, records of five parasite types in toques in Sri Lanka are reported for the first time, while Moniliformis type was reported as a first record in free ranging macaques, globally. This study clearly demonstrated that human contact and habitat modification may influence patterns of parasitic infections in macaques. As most of the parasite types identified manifest zoonotic potential, with public health implications, close associations of macaques may cause a threat to human well-being.
... In the case of S. priam, social structure is variable and can be one-male-multi-female or multi-male-multi-female like the present study (Mohnot et al., 1981). As in our study, M. sinica is also known to occur as multi-malemulti-female groups (Dittus, 1975(Dittus, , 1977Vandercone et al., 2004). In comparison with the langurs, macaque groups have a higher proportion of sub-adults, juveniles, and infants. ...
Sri Lanka is a biodiversity hotspot that is under high anthropogenic pressure. The long-term survival of its biodiversity, including primates, is under threat. Due to an increased rate of deforestation outside protected areas after the civil war in the northern dry zone, protected areas are key for the long-term persistence of primates. A rapid assessment of the population status of diurnal non-human primates in the Giritale Nature Reserve in the north-central dry zone was conducted using Reconnaissance Transect method from December 2017 to January 2018. Semnopithecus vetulus philbricki, Semnopithecus priam thersites and Macaca sinica sinica were present in the nature reserve. Mean troop sizes for S. vetulus, S. priam and M. sinica were 9.0±1.7, 21.6±6.7 and 24.5±16.3, respectively. The highest density was recorded for M. sinica (172.9 individuals/km2) while the lowest was for S. vetulus (31.8 individuals/km2). The male to female ratio was 1:1 in M. sinica, 1:1.3 in S. priam and 1:1.5 in S. vetulus. The study shows that the Giritale Nature Reserve maintains reproductively active populations of all three diurnal primates, including the Endangered S. vetulus, providing a rationale to conduct further research for instituting plans to conserve habitats in Giritale Nature Reserve.
... In Sri Lanka, there are three geographically separated subspecies of toque macaques: the common macaque (Macaca sinica sinica, Linnaeus, 1771) in the dry zone, the pale-fronted or dusky macaque (Macaca sinica aurifrons, Pocock, 1931) in the wet-zone and the mountain or the hillzone macaque (Macaca sinica opisthomelas, Hill, 1942) in the montane rainforests of the Horton Plains (Dittus, 1977). All are endemic to Sri Lanka and are listed as Endangered (International Union for Conservation of Nature and Natural Resources (IUCN), 2008; Nahallage et al., 2008). ...
Gastro-intestinal (GI) parasites of primates have a greater potential of becoming zoonotic. This potential may vary in different primates based on multiple factors such as proximity to human settlements and the climate of their habitat. We examined the GI parasites in two subspecies of toque macaque: Macaca sinica sinica (confined to the dry zone) and Macaca sinica aurifrons (confined to the wet zone) of Sri Lanka. Fresh faecal samples were collected and analysed following a modified Sheather's sucrose floatation method. A total of 90.8% (89/98) macaques were infected with one or more parasite species. There was no difference in the overall prevalence of GI parasites between the two subspecies, M. s. aurifrons (95.9%) and M. s. sinica (85.7%; χ²;χ = 3.059, p = 0.080). Sixteen parasite species were recorded including, 15 species in the M. s. sinica and 12 species in the M. s. aurifrons. Among the helminths identified, Anatrichosoma sp., Ancylostoma spp., Capillaria spp., Oesophagostomum /Bunostomum spp. and Physaloptera spp. are known to be zoonotic while Ascaris spp., Enterobius sp., Strongyloides spp. and Trichuris spp. have both zoonotic and anthroponotic potential. Among the protozoans, Balantidium coli and Buxtonella sp. are known to be zoonotic, while Entamoeba spp. and Cryptosporidium spp. have both anthroponotic and zoonotic potential. This study provides the first record of Anatrichosoma sp. and Buxtonella sp. in Sri Lanka and the first record of Cryptosporidium spp. in M. s. aurifrons. The molecular data allowed further identification and differentiation of Entamoeba nuttalli and E. coli that are known to be zoonotic and anthroponotic, respectively. The two subspecies of macaques have close interactions with humans; hence, in-depth epidemiological studies are required to understand the potential public-health risks to humans and conservation implications for macaque populations.
... In Sri Lanka, there are three geographically separated subspecies of toque macaques: the common macaque (Macaca sinica sinica, Linnaeus, 1771) in the dry zone, the pale-fronted or dusky macaque (Macaca sinica aurifrons, Pocock, 1931) in the wet-zone and the mountain or the hillzone macaque (Macaca sinica opisthomelas, Hill, 1942) in the montane rainforests of the Horton Plains (Dittus, 1977). All are endemic to Sri Lanka and are listed as Endangered (International Union for Conservation of Nature and Natural Resources (IUCN), 2008; Nahallage et al., 2008). ...
Gastrointestinal (GI) parasites in non-human primates have a greater potential to become zoonotic as well as anthroponotic. This study examined the GI parasites in two subspecies of toque macaque: Macaca sinica sinica in the dry zone and Macaca sinica aurifrons in the wet zone of Sri Lanka. Fresh faecal samples were collected from Polonnaruwa Archaeological Reserve and Peradeniya University premises, and were analysed following a modified Sheather's sucrose floatation method. Further identification and differentiation of Entamoeba sp. were conducted by PCR using species specific primers. Of the 98 macaques examined, 89 (90.8%) were infected with GI parasites. Overall, there was no difference in the prevalence of GI parasites between the two subspecies in the wet (95.9%) and dry zones (85.7% ; 2 = 3.059, p = 0.080). A total of 16 parasite species were recorded including nine helminths and seven protozoans. Among the helminths observed, Anatrichosoma sp., Ancylostoma sp., Capillaria sp., Oesophagostomum sp., and Physaloptera sp. have been identified as zoonotic while Ascaris sp., Enterobius sp., Strongyloides sp., and Trichuris sp. have been identified as both zoonotic and anthroponotic. Among the protozoans, Balantidium coli and Buxtonella sp. have been reported to cause zoonoses while Entamoeba sp. and Cryptosporidium sp. have been reported to cause both anthroponoses and zoonoses. This study provides the first record of Anatrichosoma sp. and Buxtonella sp. in Sri Lanka and the first record of Cryptosporidium sp. in the wet zone macaques. The highest overall intensity of infection was eggs of Oesophagostomum sp. (EPG = 49.02 ± 40.30) in the wet zone macaques. The molecular data confirmed the presence of E. nuttalli and E. coli, that are known to be zoonotic and anthroponotic, respectively. Urban toque macaque populations and human monkey interactions are constantly increasing in Sri Lanka. Therefore, in-depth epidemiological studies of the zoonotic and anthroponotic pathogens in both monkeys and humans are important for better understanding of potential public health risks and implications for conservation of toque macaques.
Financial assistance from the University of Peradeniya (Grant No. URG/2018/39/S) is acknowledged.
... In such instances the trouble with pest monkeys is not solved, it is merely shifted from an economically and politically strong area and imposed upon poor rural villagers [Pirta et al., 1997;Lohumi, 2004;Ramanayake, 2012] some of whom protest against the practice [Somaratna, 2012]. Furthermore, in Sri Lanka, the several sizable protected areas occur in arid regions whose carrying capacity for primates is low and cannot support the survival of translocated groups of monkeys [Dittus, 1977b[Dittus, , 2017. Translocation may have limited conservation applications [Strum and Southwick, 1986] but is not a viable solution for reducing HMC, particularly in areas of high human population density, or in general with most wildlife [Craven et al., 1998]. ...
Sri Lanka is a biodiversity hotspot with high human density that contributes to increasing human-monkey conflict (HMC). In 50 years of primate studies there, the development of HMC has been documented, and many workshops and interventions organized to ameliorate HMC. These activities prompted the present survey. In the extensive lowland dry zone of Sri Lanka, the affected nonhuman primates are the toque macaque, gray and purple-faced langurs and slender loris. We surveyed and evaluated the attitudes of rural residents towards these four species in an effort to contribute to an ethnoprimatological approach to conservation, i.e., promote a coexistence and sharing of habitat between humans and monkeys. We selected 13 villages near Polonnaruwa, located centrally in the dry zone. The four nonhuman primate species differ in their behavioral ecologies, and this influenced how frequently they were thought of as pests. Most HMC was with the macaque and gray langur, less with the purple-faced langur and least with the loris. The underlying sentiment among stakeholders towards monkeys was generally either neutral or positive. Nonetheless, the majority (80%) of people desired a translocation of the troublesome monkeys from their properties to protected areas, which is impractical. Few (< 1%) openly wanted monkeys destroyed. While a traditional reverence for monkeys provides a solid basis for science and media-based education, it also contributes to the feeding of monkeys and consequent unnatural population growth, and enhanced HMC. Public understanding of the underlying causes of HMC was poor, hindering effective solutions. A combination of a feeding ban, possibly contraceptive intervention at localized HMC trouble spots, and extensive education may be the only benign alternatives to the destruction of wild primates by a powerful minority. Coexistence through strengthening and expansion of exclusive suitable protected habitats for all wildlife is a priority.
... Large ungulates, including cervid, suid, and bovid are present throughout the Mortality profiles based on dental eruption and wear suggest that prime-aged adults were deliberately targeted. This, and the fact that the identified monkey species are today mostly arboreal and rarely venture to the ground 24,25 , suggests that they were most likely captured by targeted hunting. Trapping usually results in mortality profiles similar to those found in natural populations [26][27][28] . ...
Defining the distinctive capacities of Homo sapiens relative to other hominins is a major focus for human evolutionary studies. It has been argued that the procurement of small, difficult-to-catch, agile prey is a hallmark of complex behavior unique to our species; however, most research in this regard has been limited to the last 20,000 years in Europe and the Levant. Here, we present detailed faunal assemblage and taphonomic data from Fa-Hien Lena Cave in Sri Lanka that demonstrates specialized, sophisticated hunting of semi-arboreal and arboreal monkey and squirrel populations from ca. 45,000 years ago, in a tropical rainforest environment. Facilitated by complex osseous and microlithic technologies, we argue these data highlight that the early capture of small, elusive mammals was part of the plastic behavior of Homo sapiens that allowed it to rapidly colonize a series of extreme environments that were apparently untouched by its hominin relatives.
... During the last century, this range underwent extensive deforestation and the sizeable primary forests were drastically shrunk [9], reducing the amount of suitable habitats which has been identified as the main threat to Sri Lanka's primates [17]. Today, only few small, fragmented and isolated forests are left within the range of S. v. nestor and 81% of their habitats are in deforested areas [9,18].However, most of S. v. nestor populations are not confined to the forest boundaries and much of its habitats comprise of human-modified landscapes such as home gardens and rubber (Hevea brasiliensis) monocultures [9], giving rise to conflicts with humans. ...
Abstract
Endemic Western purple-faced langur (Semnophithecus vetulus nestor) of Sri Lanka, is an exclusively arboreal, critically endangered primate whose habitats are severely fragmented with the human population expansion. Labugama-Kalatuwawa Forest Reserve (LKFR) which is identified as the last strongholds for maintaining viable populations of the species over the long-run and Indikada Mukalana Forest Reserve (IMFR) which is located in a closer proximity to LKFR have no connection with each other at the current status. As there is no assertion of regional habitat connectivity at a metapopulation context, the study aimed to identify a potential habitat corridor for S. v. nestor between LKFR and IMFR by using GIS as a tool in connectivity modelling. Study area was first divided into 0.04 km2 grids using ‘fishnet’ tool. Five main resistance criteria for S. v. nestor movement were selected namely; land use, road density, canopy cover, human tolerance and Feeding Plant Species Richness and Density (FPSRD). Each grid was assigned with resistance values for above criteria ranging from 1 to 6. Overall resistance layer for S. v. nestor movement was created using ‘weighted overlay’ in GIS environment. The best potential habitat corridor was identified via least-cost modelling. The resultant corridor falls within an area which mainly comprises of forest and rubber (Hevea brasiliensis) monoculture. It further accounts for the highest human tolerance, canopy continuity, FPSRD and least road density. Resultant corridor can be improved by bridging existing gaps and enriching the corridor habitats which would play an important role in conservation of S. v. nestor by minimizing the isolation of local populations, ensuring the gene flow and maintaining the minimum viable metapopulation in the long run. This study further demonstrates that GIS can be used as an effective tool for least-cost modelling which helps to identify potential wildlife movement corridors at minimum cost.
... During the last century, this range underwent extensive deforestation and the sizeable primary forests were drastically shrunk [9], reducing the amount of suitable habitats which has been identified as the main threat to Sri Lanka's primates [17]. Today, only few small, fragmented and isolated forests are left within the range of S. v. nestor and 81% of their habitats are in deforested areas [9,18].However, most of S. v. nestor populations are not confined to the forest boundaries and much of its habitats comprise of human-modified landscapes such as home gardens and rubber (Hevea brasiliensis) monocultures [9], giving rise to conflicts with humans. ...
Human-Monkey Conflict (HMC) is a wide-spread issue across Sri Lanka. The wet
western lowlands, which provide habitats for both endemics: the critically endangered
Western Purple-faced Langur (Semnophithecus vetulus nestor) and the endangered Toque
Macaque (Macaca sinica), are also experiencing increasing issues of HMC. The study
aimed to assess HMC in six villages between Labugama-Kalatuwawa and Indikada
Forest Reserves in Colombo district.
A questionnaire survey was conducted, from April to June, 2016, in
systematically selected 128 households in the area, with the sampling percentage of 19%,
to determine; the presence of monkeys in home gardens and their problem causing
percentage, pattern and frequency of visiting, monkey group sizes, impacts to humans
and threats to monkeys due to HMC and human responses upon monkey visitation, in
order to achieve the aim of the study.
According to the results of the study, both species were present in 80.5% of home
gardens whereas only S. v. nestor was recorded in 14.2% and only M. sinica in 2.5%.
S. v. nestor caused problems in 82.5% of home gardens they visit whereas M. sinica
caused problems in 93.4% of home gardens. Majority of both species visited home
gardens more frequently (everyday, twice a week or once a week), all year round, without
restricting to the fruiting season. S. v. nestor commonly occurred in groups with a size of
<=5 individuals as M. sinica occurred in groups of 11-20 individuals.
When considering the impacts to humans, it was found that crop damage (93%)
predominated the other types of damage where S. v. nestor was responsible for 78.1%
and M. sinica for 62.5% of crop damages. Roof damage was the second common damage
(48%) where S. v. nestor accounted for 72.8% of damage. Majority utilized firecrackers
(35.3%) to chase the monkeys. Other methods such as throwing stones and shouting were
also recorded. Electrocution was identified as a threat for both S. v. nestor (30.7%) and
M. sinica (16.3%).
This study depicts that HMC is caused by both species, but impacts to humans
and threats to monkeys are greater with S. v. nestor. It is recommended to enrich habitats
and enhance canopy continuity between the two forests by placing a habitat corridor, in
order to minimize HMC and to conserve these threatened species.
Keywords: Human-Monkey Conflict (HMC), crop damage, conservation, habitat
corridor, Labugama-Kalatuwawa Forest Reserve, Indikada Forest Reserve
... a 0-2 m height, b mean of spot observations and activity assessment, c survey data, monkeys not really habituated, d only data for autumn and winter, e less than 1 m height, * values estimated from figure. Sources and habitat type: 1) Kurup & Kumar (1993), undisturbed wet evergreen forest; 2) Menon & Poirier (1996) Caldecott (1986a), tropical broadleaf evergreen forest surrounded by oil palm plantations, value is the mean of spot observations and activity assessments; 11) Bernstein (1967), tropical broadleaf evergreen forest, same study site as Caldecott (1986a); 12) Crockett & Wilson (1980), swamp, lowland, hill and submontane forest; 13) Lu et al (1991), mainly primary broadleaf forest; 14) Kohlhaas (1993), primary lowland rainforest, with some patches of secondary growth and grasses, 15) Dittus (1977), semi-evergreen forest, dry zone plain; 16) this study; 17) Sugiyama (1971) (2003), evergreen forest less than 5 m high; 22) Ménard & Vallet (1997), temperate decidious oak forest at Akfadou, temperate evergreen cedar-oak forest at Djurdjura; 23) Chopra et al (1992), forest; 24) Goldstein & Richard (1989) and Goldstein (1984), temperate mixed coniferous decidious forest with disturbed areas. ...
Logging and forest loss continues to be a major problem within Southeast Asia and as a result, many species are becoming threatened or extinct. The present study provides the first detailed and comprehensive ecological data on the Siberut macaque (Macaca siberu), a primate species living exclusively on the island of Siberut off the west coast of Sumatra. Our results show that M. siberu is ecologically similar to its closest relative M. nemestrina occurring on the mainland, both species being semi-terrestrial, mainly frugivorous (75-76%), exhibit a large daily travel distance for their group size and spend more time on traveling than any other macaque species. The habitat of Siberut macaques was floristically very diverse (Simpson's index D=0.97), although somewhat impoverished in tree species richness, and had a lower tree basal area and a lower rattan density compared to other forests in Malesia (both rattan and palm tree fruit being an important food resource for Macaca siberu due to their long fruiting periods). These factors may lead to a lower diversity and abundance of fruit resources, and coupled with a high degree of frugivory of Siberut macaques, may explain the large amount of traveling observed in this species. The large home range requirements and strong dependence on fruit are important factors that need to be considered when developing conservation measures for this IUCN-listed (Category Vulnerable) species.
... We used Spearman's rank correlation tests to examine relationships between dispersal characteristics (seed size [mm], percentage of feces with seeds, and dispersal distance [m]), and adult female body mass (kg). We also used Spearman's rank correlation tests to compare the number of seeds of individual plant species in a single Caldecott (1986) e Tsuji et al. (2013) f Duration of the study was not mentioned g Richter et al. (2013) h Ménard and Vallet (1996) i Mendiratta et al. (2009) and Kumar et al. (2007) j Erinjery et al. (2015) k Hladik and Hladik (1972) and Dittus (1977) l Huang et al. (2015) m O' Brien and Kinnaird (1997) n Umpathy and Kumar (2000) o Mehlman (1988) p Pombo et al. (2004) and Riley (2007) q Zhou et al. (2011) r Krishnamani (1994) and Ali (1986) Zhao et al. (1991 ) , described as Breproductive partst Su and Lee (2001) u Corlett and Lucas (1990) v Tsuji (2011) w Sengupta and Radhakrishna (2016) x Tsuji et al. (2017) y Tsuji (2011) z Sengupta et al. (2014) fecal sample, number of seed species per feces, and dispersal distance and latitude (°). We used a Mann-Whitney U test to test for differences in seed size between spat and defecated seeds. ...
The role of primates in seed dispersal is well recognized. Macaques (Macaca spp.) are major primate seed dispersers in Asia, and recent studies have revealed their role as seed dispersal agents in this region. Here, we review present knowledge of the traits that define the role of macaques as seed dispersers. The size of seeds in fruit influences whether macaques swallow (0.5–17.1 mm; median: 3.0), spit (1–37 mm; median: 7.6), or drop (8.2–57.7 mm; median: 20.5) them. Dispersal distances via defecation are several hundreds of meters (median: 259 m, range: 0–1300 m), shorter than those achieved by some mammals and birds in tropical and temperate regions. However, macaques disperse seeds by defecation at comparable distances to omnivorous carnivores, and further than passerines. Seed dispersal distance by spitting is much shorter (median: 20 m, range: 0–405 m) than by defecation. Among Asian primates, seed dispersal distances resulting from macaque defecation are shorter than those for gibbons and longer than those for langurs. The effects of seed ingestion on the percentage and speed of germination vary among both plant and macaque species. The degree of frugivory, fruit/seed handling methods, seed dispersal distance, microhabitats of dispersed seeds, and effects of dispersal on seed germination vary seasonally and interannually, and long-term studies of the ecological role of macaques are needed. Researchers have begun to assess the effectiveness of seed dispersal by macaques, secondary dispersal of seeds originally dispersed by macaques, and the effects of provisioning on seed dispersal. Future studies should also test the effects of social factors (such as age and rank), which have received little attention in studies of seed dispersal.
... Social Behaviour (Dittus, 1975;1977a;1977b; The red monkey has a multi-male -multi-female social system, accompanied by a promiscuous mating system. Genetics (Keane et al, 1997) Genetic studies have been carried out on the Polonnaruwa toque macaques using paternity exclusion analysis. ...
... In Red List assessments, Areas of Occurrence and Occupancy for primates and other mammals overestimate the available ecologically suitable habitat. Most mature natural forests are found in protected areas (including Forest Reserves), and the most extensive of these are confined to the unproductive arid and dry zones in which primates (and other water-bound mammals) either cannot be sustained at all, or only at very low densities localized near permanent water sources (Eisenberg and Lockhart 1972;McKay, 1973;Dittus 1977b). This is particularly true of the dry zone subspecies of toque macaque, purple-faced langur and loris. ...
Subspecies embody the evolution of different phenotypes as adaptations to local environmental differences in keeping the concept of the Evolutionary Significant Unit (ESU). Sri Lankan mammals, being mostly of Indian-Indochinese origins, were honed, in part, by the events following the separation of Sri Lanka from Gondwana in the late Miocene. The emerging new Sri Lankan environment provided a varied topographic, climatic and biotic stage and impetus for new mammalian adaptations. This history is manifest nowhere as clearly as in the diversity of non-endemic and endemic genera, species and subspecies of Sri Lankan mammals that offer a cross-sectional time-slice (window) of evolution in progress: 3 of 53 genera (6%), and 22 of 91 species (24%) are endemic, but incorporating subspecies, the majority 69 of 108 (64%) Sri Lankan land-living indigenous mammal taxa are diversified as endemics. (Numerical details may change with taxonomic updates, but the pattern is clear.) These unique forms distinguish Sri Lankan mammals from their continental relatives, and contribute to the otherwise strong biogeographic differences within the biodiversity hotspot shared with the Western Ghats. Regardless of the eventual fates of individual subspecies or ESU’s they are repositories of phenotypic and genetic diversity and crucibles for the evolution of new endemic species and genera. Their importance is highlighted by recent taxonomic studies that have identified more than 20% of infra-specific populations as new endemic species. Such ‘hidden species diversity’ validates not only the policy to conserve the potential for evolutionary processes as manifest by infra-specific diversity, but also, to prioritize the conservation of subspecies over their precise taxonomic definitions. The conservation of biodiversity in practice, therefore, involves firstly the official acknowledgement of the existence and importance of infra-specific diversity, especially in taxa such as primates where it is well expressed; and secondly, the protection of highly threatened natural habitats that constitute the only realistic life-supporting environments for the conservation of Sri Lanka’s diversity in mammals and many other life forms. DOI: http://dx.doi.org/10.4038/cjsbs.v42i2.6606 Ceylon Journal of Science ( Bio. Sci. ) 42(2): 1-27, 2013
... While it has been evoked that the main threat to nonhuman primates is habitat loss because of high human population pressure and the consequent demand for land (Dittus, 1977), there were no quantified data prior to this study on monkey-human relationships in Sri Lanka. This paper presents basic data on the relationship between S. vetulus nestor and humans that co-occur in two categories of land use that is common in the lowland Wet Zone, namely home gardens and rubber plantations. ...
Semnopithecus (Trachypithecus) vetulus nestor, (Family: Cercopithecidae, Sub-family Colobinae) the western purple-faced langur of Sri Lanka, is currently recognized as one of the world's 25 most endangered primate taxa. This paper seeks to identify and assess the impact of monkey-human relationships on S. vetulus nestor, in areas where monkeys and humans co-occur, and to ascertain threats to these langur populations living outside natural forests. Monkey-human conflicts were investigated in 1985 during a census of langurs at seven sites in and around Panadura and Piliyandala. More detailed data were gathered through direct observation of two habituated free ranging groups of S. vetulus nestor in home gardens and rubber monocultures at two study sites in Panadura and Piliyandala during a systematic study from 1985-1987. This was followed by opportunistic observations during 1987 - 1992 at the Panadura site. A questionnaire was administered to householders at these two sites in 1987, and habitat change was monitored periodically thereafter until 2006 at both sites. The study revealed that loss of canopy cover due to habitat destruction was the most significant threat to S. vetulus nestor in human modified environments, followed by hunting, which varied in intensity at different sites. Live capture of monkeys as pets was not a threat at any of the investigated sites. Langurs caused damage to crops and tiled roofs, and were considered pests by 47.5% and 82.4% of householders at the two main study sites. Despite this, there was high tolerance towards langurs by householders at both study sites during the 1987 survey; less than 10% of the householders wanted monkeys destroyed; and fewer were willing to do so themselves. Most people at each site (63.1% and 55.6% at Panadura and Piliyandala respectively) harassed or chased monkeys only if they caused crop or roof damage. At both sites, food competition-mainly for human edible fruit-was the main cause of conflict, followed by roof damage. The study sites exemplify scenarios in non-forested areas in the densely populated geographic range of S. vetulus nestor. This study, therefore, underscores the precarious existence of this Critically Endangered langur in human-modified habitats, which are vulnerable to change. Ensuring the survival of S. vetulus nestor requires addressing the major challenges of establishing linkages between isolated forest fragments in its range and maintaining adequate canopy cover and food trees in the main forest and modified habitats without further delay.
... Abbreviations of study sites: NP = National Park, NR = Nature Reserve, WS = Wildlife Sanctuary a 0-2m height, b mean of spot observations and activity assessment, c survey data, monkeys not really habituated, d only data for autumn and winter, e less than 1m height, * values estimated from figure Sources and habitat type: 1) Kurup & Kumar (1993), undisturbed wet evergreen forest; 2) Menon & Poirier (1996), disturbed forest; 3) Choudhury (2008), tropical wet evergreen forest and decidious plantations; 4) J. M. José Domínguez (pers. comm.), seasonal wet evergreen forest, forest group Ch; 5) Albert et al (2011), seasonal wet evergreen forest, close to the national park's visitor center, group HQ; 6) Aldrich-Blake (1980), tropical lowland evergreen forest; 7) MacKinnon & MacKinnon (1980), site at Kuala Lompat: tropical lowland evergreen forest, site in Sumatra: habitat type not given by the authors; 8) Wheatley (1980), mixed lowland forest; 9) Schülke et al (2011), dry evergreen forest; 10) Caldecott (1986a), tropical broadleaf evergreen forest surrounded by oil palm plantations, value is the mean of spot observations and activity assessments; 11) Bernstein (1967), tropical broadleaf evergreen forest, same study site as Caldecott (1986a); 12) Crockett & Wilson (1980), swamp, lowland, hill and submontane forest; 13) Lu et al (1991), mainly primary broadleaf forest; 14) Kohlhaas (1993), primary lowland rainforest, with some patches of secondary growth and grasses, 15) Dittus (1977), semi-evergreen forest, dry zone plain; 16) this study; 17) Sugiyama (1971), dry decidious forest; 18) O'Brian & Kinnaird (1997), some parts disturbed forest; 19) Giyarto (2010), Rambo I group (1 st value) mainly primary forest, Rambo II group mainly secondary forest; 20) Yotsumoto (1976), secondary broadleaf decidious forest, some parts with broadleaf evergreen trees; 21) Chatani (2003), evergreen forest less than 5m high; 22) Ménard & Vallet (1997), temperate decidious oak forest at Akfadou, temperate evergreen cedar-oak forest at Djurdjura; 23) Chopra et al (1992), forest; 24) Goldstein & Richard (1989) and Goldstein (1984), temperate mixed coniferous decidious forest with disturbed areas. ...
Feeding competition remains of research interest as it affects growth, survival and reproductive success of individuals. It also limits group size and shapes the social structure of animal groups. Feeding competition is thought to be determined by food resource characteristics, but other factors like predation risk can influence feeding competition as well. The socioecological models have been developed to explain the observed variation in social relationships, by linking resource characteristics to the type and strength of feeding competition, which ultimately influences social relationships. These models mainly focused on females, as female reproductive success is usually more limited by food than that of males. My thesis addresses two major gaps related to the feeding competition aspects of the socioecological models. Firstly, it addresses the lack of empirical data examining feeding competition under low predation risk to test some model predictions, i.e. that groups become less cohesive and feed in small feeding groups or even alone if predation risk is low, resulting in reduced contest competition. Secondly, it addresses the often neglected role of males within socioecological models, as there is some evidence that males can also actively defend food resources and thus can play an important role in between-group feeding competition. To address the first research gap, I studied within-group feeding competition in Siberut macaques (Macaca siberu), a species endemic to Siberut island (W-Sumatra, Indonesia), where predation risk is low as carnivore predators have been absent for at least 0.5 m years. In accordance with model predictions, I found that average feeding group size was small, individuals (including juveniles) were frequently feeding alone in food patches, and individuals spread out continuously without forming sub-groups. The lack of felids thus influences the foraging and feeding behavior and reduces contest competition, reflected by a very low aggression rate in food patches. I addressed the second gap of research using Assamese macaques (Macaca assamensis) at Phu Khieo Wildlife Sanctuary, Thailand. I evaluated the role and consequences of male group size on between-group competition by investigating the influence of male group size on home range size and the effect on female reproductive success. I found (indirect) evidence that male food resource defense is an important part of between-group competition in that species, and that females benefit from more males in the group through an increased home range size which increased female reproductive success. A literature review revealed that there is direct or indirect evidence for male resource defense in 17 primate species, suggesting that male resource defense may be more common than previously assumed. In sum, my thesis fills two major gaps related to feeding competition aspects of socioecological models. It contributes to the debate about the merit and validity of socioecological models by confirming model predictions for a species living under low predation risk, and shows that it is important to measure food resource characteristics on a scale relevant to the study animals. A comparison of Siberut macaques and Sulawesi macaques shows that their competitive regimes differ largely, although they all live on oceanic islands under low predation risk and feed mainly on fruits. This shows the importance of detailed measurements of behavior, food resource characteristics and other ecological conditions, and prompts us to be careful with generalizations based on coarse dietary categorizations. In addition, various factors have been previously proposed to be added to the socioecological models, to improve their explanatory power. If future studies can demonstrate that male food resource defense influences between-group feeding competition in many species, we should consider including males as an explanatory factor in future socioecological models.
... It is critical we improve our understanding of seed dispersal by cercopithecines in disturbed habitats, particularly for those species directly persecuted by humans. Further, the conservation status of all disturbance-tolerant cercopithecines Kinnaird (1997), Riley and Priston (2010), Dittus (1977), Maisels et al. (2006), andHoffman andO'Riain (2011). should be reviewed to account for important ecological role they may play. ...
... Toque macaques normally sleep safely at the terminal forks of large branches at the tops of tall emergent trees (Dittus, 1977c). Animals severely handicapped by their injuries have been observed sleeping alone at a distance from the rest of their group members, in lower branches, or even in the shrubs they were injured compared to those after they had recovered. ...
Toque macaques (Macaca sinica),inhabiting natural forest at Polonnaruwa, Sri Lanka, are frequently injured in fights with conspecifics. The behavior of known
individuals when they were injured was compared to that after they had recovered their health. Thus, injured animals rested
and alloand autogroomed more, but they foraged less and initiated fewer aggressive episodes. They spent most time being sedentary
in the safety of arboreal refuges and reduced acrobatic movements by locomoting more often terrestrially. Other group members
showed no special tolerance (or altruism) toward injury victims during the costly and highly competitive activity of foraging
for food. In fact, some injured animals received more aggression, or lost dominance rank, and thereby had their competitive
abilities further impaired. Care for the injured was manifest mostly by grooming and wound cleaning. All hair in the area
surrounding a wound, as well as dirt, scabs, and fly larvae, were removed, and saliva was applied by licking the wound (wounds
so treated healed with no obvious signs of infection). (1) Injured macaques sought and received significantly more grooming
(owing to wound care); (2) the amount so received increased with the severity of the injury; and (3) the initiative of other
group members often compensated for a victim’s inability to solicit care. Juvenile males were especially attentive to injured
adult males, suggesting that they were investing in a social bond with these adults, which might reciprocate altruism toward
their juvenile caregivers in the future. Injured juvenile females received most care from their mothers.
... I conducted field observations for this study from January 1984 to June 1985 at the Polonnaruwa Archaeological and Nature Reserve, which is situated in the northeastern dry zone of Sri Lanka. Details of the study area and the toque macaque population of approximately 500 individuals have been described by Dittus (1977b), who has maintained sociodemographic records on the population since September 1968. From three study groups (approximately 85 individuals), I individually identified all monkeys and assigned them to age--sex classes as did Dittus and Thorington (1981) and Dittus (in preparation). ...
I compared the behavior of three old postreproductive females in a wild population of toque macaques (Macaca sinica)in Polonnaruwa with those of reproductive females via focal-animal sampling techniques. Postreproductives foraged less, slept
more, and were less active overall than reproductive females were. They also had significantly lower rates of agonistic behavior,
were more peripheral, and had lower frequencies of overall affiliative contact. Although postreproductives initiated contact
with others as frequently as reproductives did, group members initiated contact with them significantly less than they did
with reproductive females. Postreproductives associated more with adult females than reproductives did and less with adult
and subadult males than high-ranking reproductives did. Juvenile and infant females associated more frequently with reproductive
females of high or low rank than with postreproductives. Postreproductives resembled low-ranking reproductive females in giving
less grooming to others than they received. This contrasts with high-ranking females, which gave more grooming to others than
they received. The results suggest that old age and cessation of reproduction are evident through the manifestation of distinct
behavioral characteristics in toque macaque females.
... Using the above annual macaque consumption rates to estimate potential macaque carrying capacity (in terms of numbers (animals ha -1) and biomass (kJ ha-l)), all habitats should support more animals than they do (Table 1). For example, the studied monkey density in Moyen Atlas cedar forests, the highest recorded for North Africa, estimated at 60-70 monkeys km -2 (Taub, 1978;Deag, 1984) contrasts with a predicted 449 monkeys km -2, a figure exceeding that of other macaques in undisturbed tropical forests (Dittus, 1977;Waser, 1986). Various authors have suggested that Barbary macaque populations are below attainable numbers due to habitat deterioration (Drucker, 1984;Fa, 1986;Mehlman, 1989b). ...
Re-introductions are increasingly used conservation tools. Often, criteria for re-introducing species are based on policies or politics and little attention paid, albeit theoretical, to understanding what ecological possibilities habitats may have in sustaining introduced animals. Assessing potential carrying capacities is complex but easier for grazers, since biomass of these herbivores is empirically correlated with habitat primary productivity.The case is made here that the Barbary macaque, Macaca sylvanus, a vulnerable North African primate with a large surplus captive stock, can be viewed as a grazer. Because of this attribute, and unlike congenerics, it is possible to estimate potential densities in extant habitats in a fashion similar to predicting stocking levels for domestic herbivores. Thus, from values of consumable primary productivity for domestic stock in Mediterranean countries and the monkey's energy requirements, attainable macaque populations in studied habitats could be much higher than actual. Though these numbers may be unreachable in nature, this study shows that present macaque populations could increase after restorative management of habitats in which re-stocking with captive-born animals may play a part. However, since only 10% of potential monkey habitat in Morocco and Algeria is occupied by the species, finding areas for releasing captive-born macaques is more advisable.
... Consuming human foods can provide free-ranging primates with significant nutritional benefits (Else and Lee, 1986; Fa and Southwick, 1988), which in turn may lead to a decrease in intensities of parasitic infections (Eley et al., 1989), as under conditions of increased nutrition, the immune system may be able to mount a more effective response to pathogen attack (Coop and Kyriazakis, 1999). Conversely, raiding crops and rubbish dumps may have significant epidemiological costs owing to an increased risk of disease transmission, both directly from humans and indirectly via contact with their bodily waste, food, rubbish, and domesticated animals (Dittus, 1974; Eley et al., 1989; Hahn et al., 2003). Despite the potential importance of anthropogenic influences on primate-parasite infections and the implications of such effects for the health of human and nonhuman primates alike, the only studies in this area have compared parasites in wild-foraging primates with those foraging on human refuse (Eley et al., 1989; Hahn et al., 2003). ...
We compared parasitic infection in a crop-raiding and a wild-foraging troop of olive baboons, Papio anubis, in Gashaka Gumti National Park, Nigeria, to quantify how crop raiding may have influenced primate-parasite interactions.
We recovered gastrointestinal parasites from fecal samples from all adult individuals in both troops and processed them via
formal-ether sedimentation. We compared parasitic species richness, prevalence, output, and load across troops. We recovered
9 parasite taxa. The wild-foraging troop had a significantly higher mean output than the crop-raiding troop for Physaloptera sp., Trichuris sp., and also a significantly higher total helminth load. The crop-raiding troop had a significantly higher mean output for
the protozoan Balantidium coli and also showed a higher parasitic species richness, with 9 species recovered compared to the 7 recorded for the wild-foraging
individuals. The changes in nutritional intake, behavior, and human proximity caused by crop raiding may have important epidemiological
impacts on wild primate populations, and the nature of such impacts may vary across different taxa of parasites.
Man the Hunted argues that primates, including the earliest members of the human family, have evolved as the prey of any number of predators, including wild cats and dogs, hyenas, snakes, crocodiles, and even birds. The authors’ studies of predators on monkeys and apes are supplemented here with the observations of naturalists in the field and revealing interpretations of the fossil record. Eyewitness accounts of the ‘man the hunted’ drama being played out even now give vivid evidence of its prehistoric significance. This provocative view of human evolution suggests that countless adaptations that have allowed our species to survive (from larger brains to speech), stem from a considerably more vulnerable position on the food chain than we might like to imagine. The myth of early humans as fearless hunters dominating the earth obscures our origins as just one of many species that had to be cautious, depend on other group members, communicate danger, and come to terms with being merely one cog in the complex cycle of life.
Limestone hills are an unusual habitat for primates, prompting them to evolve specific behavioral adaptations to the component karst habitat. From September 2012 to August 2013, we collected data on the diet of one group of Assamese macaques living in limestone forests at Nonggang National Nature Reserve, Guangxi Province, China, using instantaneous scan sampling. Assamese macaques were primarily folivorous, young leaves accounting for 75.5% and mature leaves an additional 1.8% of their diet. In contrast, fruit accounted for only 20.1%. The young leaves of Bonia saxatilis, a shrubby, karst-endemic bamboo that is superabundant in limestone hills, comprised the bulk of the average monthly diet. Moreover, macaques consumed significantly more bamboo leaves during the season when the availability of fruit declined, suggesting that bamboo leaves are an important fallback food for Assamese macaques in limestone forests. In addition, diet composition varied seasonally. The monkeys consumed significantly more fruit and fewer young leaves in the fruit-rich season than in the fruit-lean season. Fruit consumption was positively correlated with fruit availability, indicating that fruit is a preferred food for Assamese macaques. Of seventy-eight food species, only nine contributed >0.5% of the annual diet, and together these nine foods accounted for 90.7% of the annual diet. Our results suggest that bamboo consumption represents a key factor in the Assamese macaque's dietary adaptation to limestone habitat. Am. J. Primatol. © 2014 Wiley Periodicals, Inc.
Even though the macaques are one of the most studied of primate groups, the Barbary macaque (Macaca sylvanus L.), has been relatively neglected. The macaque of Gibraltar has been known for long, but, there has been little scientific interest in them despite their proximity to Europe. The earliest mention of the macaque in the wild goes back to ancient times, yet the first serious systematic study of the animal’s behaviour and ecology was only carried out less than a decade ago (Deag, 1974).
Food handouts from visitors to Mt. Emei, in The People’s Republic of China, have considerably increased the diversity of food
available to an indigenous population of Macaca thibetana.Some 43% of the feeding time was spent at the trail area frequented by tourists. Ranging behavior was of two kinds: wandering
around within the group’s most densely used areas and making peripheral excursions between the areas. Three kinds of trail-area
use were observed: three-group overlapping, two-group overlapping, and exclusive. M. thibetanatended to use sheltered sites for sleeping, to ensure safety and/or to keep dry in a rainy habitat. Exclusively and successively
used sleeping sites were noted. The average size of the home range per group was 3 km
2; the average population density for the entire range was 13/km2, and the biomass was 109 kg/km2. The population may be growing, a possibility that is also supported by previous analyses using data on group composition.
This paper examines crop damage by mammals and the farmers' experiences of crop losses around Gashaka village on the south-western border of Gashaka Gumti National Park, Nigeria. Data were collected via a weekly count of damaged maize crops in 23 fields in the wet season and 30 in the dry season. We examined: (i) seasonal frequency and extent of damage, (ii) losses experienced relative to expected gains, and (iii) aspects of fields in relation to their susceptibility to raiding. Cows caused the greatest amount of damage during the year. Tantalus monkeys were the wild species that caused the most damage. The experience of individual farmers varied from no damage to complete loss of an entire season's crop. Currently the only apparent certainty in predicting losses for farmers was that those farmers with fields closer to wildlife refuges are more likely to experience greater losses. The importance of domestic animal crop damage should not be underestimated in its impact on farmers' livelihoods. Management of crop-raiding in general requires an integrated approach taking domestic animals into account. Pro-active guarding is suggested as having potential to reduce crop losses in Gashaka.
Logging and forest loss continues to be a major problem within Southeast Asia and as a result, many species are becoming threatened or extinct. The present study provides the first detailed and comprehensive ecological data on the Siberut macaque (Macaca siberu), a primate species living exclusively on the island of Siberut off the west coast of Sumatra. Our results show that M. siberu is ecologically similar to its closest relative M. nemestrina occurring on the mainland, both species being semi-terrestrial, mainly frugivorous (75-76%), exhibit a large daily travel distance for their group size and spend more time on traveling than any other macaque species. The habitat of Siberut macaques was floristically very diverse (Simpson's index D=0.97), although somewhat impoverished in tree species richness, and had a lower tree basal area and a lower rattan density compared to other forests in Malesia (both rattan and palm tree fruit being an important food resource for Macaca siberu due to their long fruiting periods). These factors may lead to a lower diversity and abundance of fruit resources, and coupled with a high degree of frugivory of Siberut macaques, may explain the large amount of traveling observed in this species. The large home range requirements and strong dependence on fruit are important factors that need to be considered when developing conservation measures for this IUCN-listed (Category Vulnerable) species.
We investigated the causes and consequences of crop-raiding for the ecology and life-history of two troops of olive baboons
studied in Nigeria’s Gashaka Gumti National Park over 8 years. Kwano troop feeds entirely on wild foods whilst the Gamgam
troop regularly consumes crops grown within its home-range. Crop-raiding provides both energetic and reproductive advantages
as Gamgam troop spent less time travelling and feeding and more time resting and socialising. The crop-raiding troop has also
shorter inter-birth intervals and lower infant mortality. Costs to crop-raiding due to chasing and attacks by farmers are
outweighed by the benefits of increased access to high-quality foods, a reduced susceptibility to pathogen loads, and a consequently
increased reproductive output.
KeywordsHuman-wildlife conflict-Crop-raiding-Food-enhancement-Forest baboons
Developmental, biochemical, and behavioral concomitants of voluntary excessive alcohol consumption were investigated using
a nonhuman primate model. Studies were designed to investigate potential neurobiological and behavioral parallels of Cloninger’s
subtypes of type I and type II alcoholism in nonhuman primates. The studies have shown that a subpopulation of primates chronically
consume intoxicating amounts of alcohol. Subjects that chronically consume intoxicating amounts of alcohol often exhibit neurobiological
and behavioral features that were predicted by Cloninger’s model for subtypes of alcoholism among humans. Investigations showed
that behavior patterns and biological indices that characterize high anxiety, whether constitutionally or stress induced,
were correlated with high rates of alcohol consumption, consistent with predictions for type I alcoholism. Early untoward
rearing experiences that increased anxiety increased the probability that subjects would chronically drink alco h olto intoxication.
Investigations of type II-like alcohol consumption patterns focused on subjects with low central nervous system (CNS) serotonin
functioning [as measured by reduced cerebrospinal fluid (CSF) concentrations of the serotonin metabolite 5-hydroxyindoleacetic
acid (5-HIAA)]. CSF 5-HIAA in infancy was shown to be a relatively stable neurobiological trait across development into adulthood.
An individual CSF 5-HIAA concentration in infancy was shown to be a consequence of paternal and maternal genetic influences.
Early parental neglect reduced CSF 5-HIAA concentrations. Low CSF 5-HIAA and CNS norepinephrine functioning were shown to
predict excessive alcohol consumption in adolescence. Behaviorally, subjects with low CSF 5-HIAA demonstrated impaired impulse
control, which resulted in excessive and inappropriate aggression, infrequent and inept social behaviors, low social status,
social isolation and expulsion from social groups at an early age, and high rates of early mortality. With some exceptions,
these findings were consistent with predictions from Cloninger’s type II model of excessive alcohol consumption among men
who exhibit impaired impulse control and violent and antisocial behaviors.
Patterns of feeding ecology among the living macaques conform poorly with recognized phyletic distinctions within the genus
because there is an important ecological division which cross-cuts phyletic groupings. This division, between weed species
and non-weed species, is based on the differing abilities of macaques to tolerate and even prosper in close association with
human settlements. Based on available information about their ecology in the wild, we tentatively assign macaque species to
these two categories. Finally, we consider the implications of our argument for scenarios of the initial spread of the macaques.
This paper presents the results of a general review of predation on nonhuman primates as a selective force in primate evolution.
Testable hypotheses derived from the literature on predation on primates, concerning sexual dimorphism, male defense, group
size, solitaries, transfer, subgrouping, and sex ratio, were applied to the available data on populations with varying predation
rates in search of significant correlations. All seven hypotheses were supported, indicating that predation is and has been
an important determinant of primate evolutionary history. Suggestions for accumulating a larger and more accurate body of
information on predation rates on primates are offered.
Sleep results in a decrease in alertness, which increases an animal’s vulnerability to predation. Therefore, choice of sleeping
sites would be predicted to incorporate predator-avoidance strategies. The current study, conducted in two national parks
in southern India, examined the behaviors adopted by bonnet macaques (Macaca radiata) to reduce the risk of being preyed upon while sleeping. Bonnet macaques from an urban setting with a low predatory risk
were included for comparison. The physical characteristics of the sleeping sites in the forest corresponded with features
that were most difficult for predators to access; bonnet macaques selected emergent trees with high boles near human settlements.
These trees typically overhung water. Within the canopy, individuals slept in huddled subgroups near the terminal ends of
branches, preferentially selecting branches over water. Subgroups were generally composed of members of the same age and sex,
which likely promoted social bonding. Adult males and females with infants selected branches higher than members of other
age and sex categories. The lateral distances of individuals along branches from the main trunk were similar across demographic
categories. The size of a subgroup appeared to be limited by the weight a branch could support; lateral distances were maintained
by regulation of mean subgroup weight, with heavier individuals forming smaller subgroups. The urban troop slept on the top
of a building. Subgroup compositions at the urban site were similar to those at the forest sites. However, subgroup size,
not restricted by branch fragility, resulted in larger subgroups than those found in the forest. Our results indicate that
bonnet macaques adopted a suite of behaviors that reduced their risk of being preyed upon at night by selecting sleeping sites
that minimized predator encounters and by selecting the safest locations within the canopy.
Based on study of 116 museum specimens and review of relevant literature, a new species account ofMacaca sinica, the Sri Lanka toque macaque, is presented. External and cranial characters of the species are described and analyzed. A
summary of natural history of the species includes information on habitats, arboreal-terrestrial preferences, predators, diet,
relations with other primate species, density, troop size and composition, home range area, and reproductive biology. Two
subspecies ofM. sinica are recognized, northernM. s. sinica (Linnaeus, 1771) and southwesternM. s. aurifrons (Pocock, 1931). Geographic ranges of these two subspecies meet in a 50–200 km broad contact zone in which representatives of both
subspecific phenotypes are encountered (35s. sinica phenotypes; 8s. aurifrons phenotypes in 43 contact zone specimens examined). An annotated gazetteer of known macaque localities in Sri Lanka provides
information concerning available museum specimens and field reports by collectors or observers. Comparative study of three
remaining species in thesinica group (M. radiata, M. assamensis, & M. thibetana) is in progress.
A seroepidemiological study of arboviruses infecting 115 wild toque macaques (Macaca sinica) at Polonnaruwa, Sri Lanka showed a high prevalence of antibodies to dengue and Lumbo viruses. There was low seroprevalence of Chandipura (2/115) and Batai (1/115) virus antibodies, but no seropositivity to Chikungunya or Sindbis. There was no serological evidence of infection by Japanese encephalitis (JE) virus in spite of large human epidemics in the study area, indicating that toque macaques are unlikely to be an epidemiologically relevant host in the maintenance cycle of JE virus.
Dengue is one of the most rapidly emerging diseases in the tropics. Humans are the principal reservoir of dengue viruses. It is unclear if nonhuman primates also serve as a reservoir of human dengue viruses under certain conditions. In this study, a cross-sectional serologic survey was carried out to characterize the pattern of transmission of a recently identified dengue virus among toque macaques in Sri Lanka. The results indicated that an epizootic dengue virus was active among the macaques. A single epizootic had taken place between October 1986 and February 1987 during which 94% of the macaques within the 3 km2 study site were exposed to the virus. The epizootic was highly focal in nature because macaques living 5 km from the study population were not exposed to the virus. The transmission of dengue viruses among macaques in the wild may have important public health implications.
Studies on a living and freshly dead male ofM. assamensis at Y.R.P.R.C. supplemented by notes on a living pair and their male offspring observed at the Z.S.L., enable us to supplement existing data on the somatology, craniology, dental anatomy and behavioural features of the species. Collectively the new data necessitate taxonomic revision of the status of the species, viz: its removal from immediate association withM. mulatta (subgenusMaimon) and alignment within the subgenusZati. Zoogeographical discontinuity in this subgenus is compared with that of the subgenusSilenus.