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Department of Social Sciences
Faculty of Humanities and Social Sciences
Professor Anna Nekaris is a Professor in Anthropology and Primate Conservation studying the unique group of evolutionary distinct primates known as the Asian lorises. Her studies cover all eleven species, including six she named or elevated from subspecies. Anna is the Course Tutor for the highly acclaimed MSc Primate Conservation, Director of the Little Fireface Project and Convenor of the Nocturnal Primate Research Group. She completed her BA in Anthropology at the University of Missouri Columbia,USA in 1993, followed by a Certificat d’Universite de Primatologie from the Universite de Louis Pasteur Strasbourg France in 1994 and her PhD in Anthropology at Washington University St Louis, USA in 2000. Anna’s research on lorises ranges from behavioural ecology in zoos, rescue centres and in the wild, museum studies, genetics, acoustics, taxonomy, conservation education and now a novel study of chemical ecology and how this bizarre primate is one of the only mammals that produces venom. Despite reports of this extraordinary phenomenon 40 years ago, virtually nothing is known about how slow lorises use venom. She has supervised more than 60 postgraduate students. Anna is the Co-Editor-in-Chief of Folia Primatologica, the journal of the European Society of Primatology.
I focus on the behaviour, ecology, taxonomy and conservation of nocturnal mammals. I work mainly in Asia, where I have conducted research in 12 countries. I am a long-standing member of the Nocturnal Primate Research Group and Director of the Little Fireface Project, a charity and research project that works to conserve understudied obscure nocturnal mammals. The main countries where I have conducted my work are India (slow and slender lorises); Sri Lanka (langurs, macaques, slender lorises, civets, small cats); Cambodia (pygmy slow lorises) and Indonesia, where I now run a long-term project on the Critically Endangered slow loris. Topics of my work have included: evolution of venom in mammals, thermoregulation in slow lorises, evolution of exudativory in primates, and using morphology to distinguish species.
The function of colouration in animals includes concealment, communication and signaling, such as the use of aposematism as a warning signal. Aposematism is unusual in mammals, and exceptions help us to understand its ecology and evolution. The Javan slow loris is a highly territorial venomous mammal that has a distinctive facial mask and monochromatic vision. To help understand if they use aposematism to advertise their venom to conspecifics or predators with different visual systems, we studied a population in Java, Indonesia. Using ImageJ, we selected colours from the facial masks of 58 individuals, converted RBG colours into monochromatic, dichromatic and trichromatic modes, and created a contrast index. During 290 captures, we recorded venom secretion and aggressiveness. Using Non-metric Multidimensional Scaling and generalised additive models for location, scale and shape, we found that young slow lorises differ significantly from adults, being both more contrasting and more aggressive, with aggressive animals showing fewer wounds. We suggest aposematic facial masks serve multiple purposes in slow lorises based on age. Change in colouration through development may play a role in intraspecific competition, and advertise toxicity or aggressiveness to competitors and/or predators in juveniles. Aposematic signals combined with intraspecific competition may provide clues to new venomous taxa among mammals.
Canopy bridges are increasingly used to reduce fragmentation in tropical habitats yet monitoring of their impact on the behavior of primates remains limited. The Javan slow loris (Nycticebus javanicus) is endemic to Java, Indonesia, where the species most often occurs in human-dominated, highly patchy landscapes. Slow lorises cannot leap, are highly arboreally adapted, and are vulnerable on the ground. To increase arboreal connectivity, as part of a long-term conservation project in Cipaganti, West Java, we built and monitored seven slow lorises bridges of two types – waterline or rubber – and monitored their use by seven adult individuals from 2016-2017. Motion triggered camera traps collected data for 195 ± SD 85 days on each bridge. We collected 341.76 hours (179.67 h before and 162.09 h after the installation of bridges) of behavioral and home range data via instantaneous sampling every 5-min, and terrestrial behavior (distance and duration of time spent on the ground) via all occurrences sampling. We found that slow lorises used bridges on average 12.9 ± SD 9.7 days after their instalment mainly for travelling. Slow lorises showed a trend towards an increase in their home range size (2.57 ha before, 4.11 ha after; p=0.063) and reduced ground use (5.98 s/h before, 0.43 s/h; p=0.063) after implementation of bridges. Although the number of feeding trees did not change, new feeding trees were included in the home range, and the proportion of data points spent travelling and exploring significantly decreased (p=0.018). Waterline bridges serve a purpose to irrigate the crops of local farmers who thus help to maintain the bridges, and also ascribe value to the presence of slow lorises. Other endemic mammal species also used the bridges. We advocate the use and monitoring of artificial canopy bridges as an important supplement for habitat connectivity in conservation interventions.
Bespoke microsatellite marker panels are increasingly affordable and tractable to researchers and conservationists. The rate of microsatellite discovery is very high within a shotgun genomic data set, but extensive laboratory testing of markers is required for confirmation of amplification and polymorphism. By incorporating shotgun next‐generation sequencing data sets from multiple individuals of the same species, we have developed a new method for the optimal design of microsatellite markers. This new tool allows us to increase the rate at which suitable candidate markers are selected by 58% in direct comparisons and facilitate an estimated 16% reduction in costs associated with producing a novel microsatellite panel. Our method enables the visualisation of each microsatellite locus in a multiple sequence alignment allowing several important quality checks to be made. Polymorphic loci can be identified and prioritised. Loci containing fragment‐length‐altering mutations in the flanking regions, which may invalidate assumptions regarding the model of evolution underlying variation at the microsatellite, can be avoided. Priming regions containing point mutations can be detected and avoided, helping to reduce sample‐site‐marker specificity arising from genetic isolation, and the likelihood of null alleles occurring. We demonstrate the utility of this new approach in two species: an echinoderm and a bird. Our method makes a valuable contribution towards minimising genotyping errors and reducing costs associated with developing a novel marker panel. The Python script to perform our method of multi‐individual microsatellite identification (MiMi) is freely available from GitHub (https://github.com/graemefox/mimi).
Only a handful of primate taxa use ultrasonic vocalisations (those ≥20 kHz) to communicate. The extent and uses of ultrasonic communication remain poorly understood, potentially ranging from echolocation, advertisement of reproductive status and resource availability, social cohesion, to predator avoidance. Here, using active acoustics whereby the study subjects were observed throughout their activity period, we describe the first purely ultrasonic call from a strepsirrhine primate (family Lorisidae), recorded in a completely wild setting, and hypothesise about its function. We identified one type of ultrasonic call, the doublet click, from 14 Javan slow lorises (Nycticebus javanicus) produced by males and females of juvenile, subadult and adult ages within their social groups (n = 791, mean = 46.0 kHz). We ran quadratic discriminant function analysis, finding dominant frequency and doublet click duration as the key parameters for identifying individuals’ sex and age. Significantly more vocalisations were produced during affiliative social behaviour, suggesting that the call serves a social cohesion function. Considering the range of other cryptic behaviours, including slow and silent locomotion, and the high degree of territoriality associated with venomous attacks on conspecifics, the call may also serve as a safety strategy, allowing family members to regulate distance from other slow lorises and to communicate cryptically whilst avoiding predators.
Among primates, the suborder Haplorhini is considered to have evolved a consolidated monophasic sleep pattern, with diurnal species requiring a shorter sleep duration than nocturnal species. Only a few primate species have been systematically studied in their natural habitat where environmental variables, including temperature and light, have a major influence on sleep and activity patterns. Here we report the first sleep study on a nocturnal primate performed in the wild. We fitted seven wild Javan slow lorises (Nycticebus javanicus) in West Java, Indonesia with accelerometers that collected activity data, and installed climate loggers in each individual’s home range to collect ambient temperature readings (over 321 days in total). All individuals showed a strictly nocturnal pattern of activity and displayed a striking synchronisation of onset and cessation of activity in relation to sunset and sunrise. The longest consolidated rest episodes were typically clustered near the beginning and towards the end of the light period, and this pattern was inversely related to daily fluctuations of the ambient temperature. The striking relationship between daily activity patterns, light levels and temperature suggests a major role of the environment in shaping the daily architecture of waking and sleep. We concluded that well-known phenotypic variability in daily sleep amount and architecture across species may represent an adaptation to changes in the environment. Our data suggest that the consolidated monophasic sleep patterns shaped by environmental pressures observed in slow lorises represent phylogenetic inertia in the evolution of sleep patterns in humans.
The rise of palm oil as the world’s most consumed vegetable oil has coincided with exponential growth in palm oil research activity. Bibliometric analysis of research outputs reveals a distinct imbalance in the type of research being undertaken, notably a disproportionate focus on biofuel and engineering topics. Recognizing the expansion of oil palm agriculture across the tropics and the increasing awareness of environmental, social, and economic impacts, we seek to reorientate the existing research agenda toward one that addresses the most fundamental and urgent questions defined by the palm oil stakeholder community. Following consultation with 659 stakeholders from 38 countries, including palm oil growers, government agencies, non-governmental organizations, and researchers, the highest priority research questions were identified within 13 themes. The resulting 279 questions, including 26 ranked as top priority, reveal a diversity of environmental and social research challenges facing the industry, ranging from the ecological and ecosystem impacts of production, to the livelihoods of plantation workers and smallholder communities. Analysis of the knowledge type produced from these questions underscores a clear need for fundamental science programmes, and studies that involve the consultation of non-academic stakeholders to develop “transformative” solutions to the oil palm sector. Stakeholders were most aligned in their choice of priority questions across the themes of policy and certification related themes, and differed the most in environmental feedback, technology and smallholder related themes. Our recommendations include improved regional academic leadership and coordination, greater engagement with private and public stakeholders in Africa, and Central and South America, and enhanced collaborative efforts with researchers in the major consuming countries of India and China.
Time is considered a resource in limited supply, and temporal niche separation is one of the most common strategies that allow ecologically similar species to live in sympatry. Mechanisms of temporal niche separation are understudied especially in cryptic animals due to logistical problems in gathering adequate data. Using high-frequency accelerometers attached to radio-collars, we investigated whether the ecologically similar lemurs Avahi meridionalis and Lepilemur fleuretae in the lowland rainforest of Tsitongambarika, south-eastern Madagascar, show temporal niche separation. Accelerometers stored data with a frequency of 1 Hz for a total of 71 days on three individuals of A. meridionalis and three individuals of L. fleuretae. We extrapolated motor activity patterns via the unsupervised learning algorithm expectation maximisation and validated the results with systematic behavioural observations. Avahi meridionalis showed peaks of activity at twilights with low but consistent activity during the day, while L. fleuretae exhibited more activity in the central hours of the night. Both lemur species had their activity pattern entrained by photoperiodic variations. The pair-living A. meridionalis was found to be lunarphilic while the solitary-living L. fleuretae was lunarphobic. We suggest that these activity differences were advantageous to minimise feeding competition, as an anti-predator strategy, and/or for dietary-related benefits. These findings demonstrate a fine-tuned temporal partitioning in sympatric, ecologically similar lemur species and support the idea that an activity spread over the 24-h, defined here as cathemerality sensu lato, is more common than previously thought in lemurs.
Ecologically similar species may exhibit temporal niche partitioning and separate their peaks of activity when co-occurring in an area. We show for the first time that the mainly nocturnal genus Avahi can exhibit high crepuscular activity with low but consistent bouts of activity (up to 44.6% of daily activity) during the day. We defined this activity as cathemerality sensu lato as opposed to the cathemerality sensu stricto observed in Eulemur sp. We suggest that this flexible activity may be advantageous for the species to minimise feeding competition and predatory pressure, and/or to provide dietary-related benefits. This finding in the secondary nocturnal genus Avahi supports the idea that activity patterns in lemurs are graded and traditional categorisations are inadequate.
Environment and diet are key factors which shape the microbiome of organisms. There is also a disparity between captive and wild animals of the same species, presumably because of the change in diet. Being able to reverse the microbiome to the wild type is thus particularly important for the reintroduction efforts of Critically Endangered animals. The Javan slow loris (Nycticebus javanicus) is a suitable model, being kept in the thousands within rescue centres throughout Southeast Asia. With next-generation sequencing, we show how a naturalistic diet impacts the gut microbiome of captive slow lorises (Primates: Nycticebus). A comparison of the microbiome of wild animals with captive animals that had been fed a standard captive or improved diet reveals strong microbiome differences between wild and captive animals; however, diet changes failed to alter the microbiome of captive populations significantly. Bifidobacterium was the most abundant genus in wild animals (46.7%) while Bacteroides (11.6%) and Prevotella (18.9%) were the most abundant in captive animals fed the captive and improved diets, respectively. Correlation analyses of nutrients with microbial taxa suggest important implications in using nutrition to suppress potential pathogens, with soluble fibre and water-soluble carbohydrates both being associated with opposing microbiome profiles. The improved diet significantly increased microbe diversity, which exemplifies the importance of high fibre diets; however, wild individuals had lower diversity, which contradicts recent studies. Detection of methanogens appeared to be dependent on diet and whether the animals were living in captivity or in the wild. This study highlights the potential of nutrition in modulating the microbiome of animals prior to release. Unexpectedly, the results were not as significant as has been suggested in recent studies.
Comparative behavioural research reveals both intra- and inter-species diversity among primates. Few long-term behavioural studies have been conducted on African nocturnal primates. Here we describe and compare behavioural and ecological observations on two species of pottos (Perodicticus ibeanus and P. edwardsi) across ten sites. We observed a total of 51 P. edwardsi and 28 P. ibeanus. We recorded all 21 postures within an established lorisid ethogram, as well as 42 of 50 behaviours. Eating, locomotion, freezing, resting and sniffing were the most common behaviours. We recorded behaviours not previously described for perodicticines, including bark chewing and unique vocalisations. Three species of pottos are now recognised, with potentially more species to be revealed within this cryptic and nocturnal genus. Although there are similarities among potto species, we show that unique ecological adaptations and behaviours may further elucidate their diversity.
For endangered species management it is imperative that there is a shared understanding of the different beliefs, opinions and factual knowledge about different aspects of the conservation programme. To allow this to be taken into account, detailed assessments need to be made of these views, how they differ between individuals, and crucially, what beliefs and views are shared. These assessments require tools from both the natural and the social sciences. Here we focus on the beliefs, opinions and knowledge about Javan slow lorises in 12 Sundanese communities of West Java, Indonesia. Javan slow lorises are small, nocturnal, venomous primates that are threatened by habitat loss and over-exploitation for the illegal pet trade. Based on detailed interviews with 79 informants, and using cluster and cultural domain analyses, we identify and document five different topics, i.e. Trade and exploitation, Taboos against disturbing or capturing, Venomous primates, Blood myths and Mystical powers. The most salient topics were factual (activity pattern, habitat use) and the taboo on collecting or disturbing slow lorises. In communities where there were strong traditions, taboos and beliefs in place, slow lorises were found in seemingly unlikely habitats, in or adjacent to the villages; where these were absent slow lorises were less known to the communities and the slow lorises were either less abundant or absent. We conclude that it is imperative that any management programme or species action plan implemented in West Java has to take into account the traditions, beliefs and taboos regarding slow lorises.
The internet is gaining importance in global wildlife trade and changing perceptions of threatened species. There is little data available to examine the impact that popular Web 2.0 sites play on public perceptions of threatened species. YouTube videos portraying wildlife allow us to quantify these perceptions.
Focussing on a group of threatened and globally protected primates, slow lorises, we quantify public attitudes towards wildlife conservation by analysing 12,411 comments and associated data posted on a viral YouTube video ‘tickling slow loris’ over a 33-months period. In the initial months a quarter of commentators indicated wanting a loris as a pet, but as facts about their conservation and ecology became more prevalent this dropped significantly. Endorsements, where people were directed to the site by celebrities, resulted mostly in numerous neutral responses with few links to conservation or awareness. Two conservation-related events, linked to Wikipedia and the airing of a television documentary, led to an increase in awareness, and ultimately to the removal of the analysed video.
Slow loris videos that have gone viral have introduced these primates to a large cross-section of society that would not normally come into contact with them. Analyses of webometric data posted on the internet allow us quickly to gauge societal sentiments. We showed a clear temporal change in some views expressed but without an apparent increase in knowledge about the conservation plight of the species, or the illegal nature of slow loris trade. Celebrity endorsement of videos showing protected wildlife increases visits to such sites, but does not educate about conservation issues. The strong desire of commentators to express their want for one as a pet demonstrates the need for Web 2.0 sites to provide a mechanism via which illegal animal material can be identified and policed.
More species of nocturnal primates are now recognized than in the past, because many are cryptic species. Subtle morphological disparities, such as pelage pattern and color variation, vocal cues, and genetics have aided in elucidating the number of diagnosable species in a genus. The slow lorises (genus Nycticebus) once included only two species, but recent taxonomic studies resulted in the description of three additional species; further incompletely explored variability characterizes each of the currently described species. The Bornean loris in particular is characterized by pelage and body size variation. In this study, we explored facemask variation in the Bornean loris (N. menagensis). Differing facemask patterns, particularly influenced by the amount of white on the face, significantly clustered together by geographic regions, separated by notable geographic boundaries. Our results support the recognition of four species of Bornean lorises: N. menagensis, N. bancanus, N. borneanus, and N. kayan. Genetic studies are required to support these findings and to refine further our understanding of the marked variability within the Bornean loris populations.
Long-term monitoring programs, wildlife surveys, and other research involving species population assessment require reliable data on population status. Given the logistically challenging nature of some species’ habitats and cryptic behaviors, collecting these data can prove to be a considerable barrier. We used detection/nondetection data from pileated gibbons (Hylobates pileatus) in the Cardamom Mountains of southwest Cambodia to estimate their population occupancy and detectability. We modeled occupancy using elevation, tree height, tree density, tree diversity, and disturbance covariates. Modeling demonstrated that 83% of the sites are occupied by Hylobates pileatus and that the detectability of the species varies positively with elevation. No clear relationship between habitat quality covariates and occupancy of Hylobates pileatus emerged. Effort analysis based on model estimates demonstrated that at high elevations, less than half the number of site visits is needed to attain the same detectability estimate precision as across all elevations. We suggest that human activities at low elevations, which affect forest composition, are the central factors impacting the detectability and occupancy of Hylobates pileatus. Longer sampling durations and/or a higher number of site visits, especially at lower elevations, increase precision of the occupancy estimator for the least effort. For effective future monitoring and research for this and similar species, using this relatively simple method, applied with repeat site visits, would allow a longitudinal comparison of detection at sites in difficult terrain.
Linking predator avoidance and social organisation predicts that large groups are favoured under heavy predation pressure but that small, inconspicuous groups may do equally well by avoiding detection altogether. We explored the relationships between antipredator behaviour (vocalisation, concealment, fleeing), detectability (colouration, group size) and social organisation in arboreal langurs. Three clear antipredation conditions emerged: (1) exemplified by Presbytis melalophos--brightly-coloured species (red, yellow) with contrasting colours, living in large unimale-multifemale groups (>10 individuals), that vocalised frequently and that flee loudly through the canopy; (2) exemplified by P. comata--greyish species (some contrasting colours), living in intermediate, unimale-multifemale or 1-male-1-female groups (approx. 7 individuals), that vocalise infrequently and that flee through the middle forest layers; (3) exemplified by P. frontata--dull-coloured species without contrast, living in small unimale-multifemale or 1-male-1-female groups (<5 individuals), that may freeze upon detection, and that may vocalise mainly during the night. Crypsis as an antipredator strategy is restricted to taxa that occur in 1-male-1-female groups. This wide range of antipredator strategies within a monophyletic taxon living in the same general area with a similar suite of predators facing similar predator pressures appears to be unique among the order Primates.
Trade in primates is seen as a significant impediment to their conservation. Primates are traded both domestically and internationally, in order to supply, amongst others, biomedical industries and pharmaceutical markets, the entertainment business, or pet markets. Primate meat is consumed globally, whereas body parts are used as ingredients in traditional medicine or sold as curios. All international trade in primates is regulated through the Convention on International Trade in Endangered Species of Wild Flora and Fauna (CITES), to which all but 2 primate range countries are signatory. The last 15 years has seen a linear increase in the export of live primates (each year 3500 more individuals are exported), with China being, numerically, the largest exporter. While the trade in live primates worldwide involves tens, if not hundreds, of thousands of individuals a year, the trade in dead primates involves millions of animals a year. We introduce here a series of studies dealing with various aspects of the primate trade. We hope that these studies will urge others to quantify the extent of trade in primates alive and dead in both domestic and international contexts, allowing us to find ways to mitigate the consequences of this trade to the conservation of primates.
Aim: Data on geographical ranges are essential when defining the conservation status of a species, and in evaluating levels of human disturbance. Where locality data are deficient, presence-only ecological niche modelling (ENM) can provide insights into a species' potential distribution, and can aid in conservation planning. Presence-only ENM is especially important for rare, cryptic and nocturnal species, where absence is difficult to define. Here we applied ENM to carry out an anthropogenic risk assessment and set conservation priorities for three threatened species of Asian slow loris (Primates: Nycticebus). Location: Borneo, Java and Sumatra, Southeast Asia. Methods: Distribution models were built using maximum entropy (MaxEnt) ENM. We input 20 environmental variables comprising temperature, precipitation and altitude, along with species locality data. We clipped predicted distributions to forest cover and altitudinal data to generate remnant distributions. These were then applied to protected area (PA) and human land-use data, using specific criteria to define low-, medium- or high-risk areas. These data were analysed to pinpoint priority study sites, suitable reintroduction zones and protected area extensions. Results: A jackknife validation method indicated highly significant models for all three species with small sample sizes (n = 10 to 23 occurrences). The distribution models represented high habitat suitability within each species' geographical range. High-risk areas were most prevalent for the Javan slow loris (Nycticebus javanicus) on Java, with the highest proportion of low-risk areas for the Bornean slow loris (N. menagensis) on Borneo. Eighteen PA extensions and 23 priority survey sites were identified across the study region. Main conclusions: Discriminating areas of high habitat suitability lays the foundations for planning field studies and conservation initiatives. This study highlights potential reintroduction zones that will minimize anthropogenic threats to animals that are released. These data reiterate the conclusion of previous research, showing MaxEnt is a viable technique for modelling species distributions with small sample sizes.
In this study we describe tree hole characteristics and use by the hairy-eared dwarf lemur (Allocebus trichotis) to determine habitat needs, potential functions of tree holes and sleeping group composition. We radio-tracked 6 adult individuals between April and November 2007 in the Analamazaotra Special Reserve. Tree holes were 1-9 m high (median: 7 m), in living trees measuring 26-54 cm in diameter at breast height (median: 32 cm), and could be a limiting resource. Each individual used 4 or 5 tree holes and had high nest fidelity. Animals most often slept socially in mixed-sex groups of 2-6 individuals and occasionally shared a tree hole with white-tailed tree rats (Brachytarsomys albicauda). We identified two sleeping groups: one composed of 2 adult males, 2 adult females and 2 juveniles; one composed of at least 2 adult females and 2 juveniles. Although tree holes were generally group exclusive, some intergroup sleeping was observed. Tree holes could have antipredator and thermoregulatory functions. Further research into sleeping hole availability, nest use and the degree of niche separation or competition between sympatric Cheirogaleidae and other tree hole users (e.g. endemic rodents) is needed to assess better the conservation needs of these species.
We integrate information from the fossil record, morphology, behavior and molecular studies to provide a current overview of lorisoid evolution. Several Eocene prosimians of the northern continents, including both omomyids and adapoids, have been suggested as possible lorisoid ancestors, but these cannot be substantiated as true strepsirhines. A small-bodied primate, Anchomomys, of the middle Eocene of Europe may be the best candidate among putative adapoids for status as a true strepsirhine. Recent finds of Eocene primates in Africa have revealed new prosimian taxa that are also viable contenders for strepsirhine status. Plesiopithecus teras is a Nycticebus-sized, nocturnal prosimian from the late Eocene, Fayum, Egypt, that shares cranial specializations with lorisoids, but it also retains primitive features (e.g. four premolars) and has unique specializations of the anterior teeth excluding it from direct lorisiform ancestry. Another unnamed Fayum primate resembles modern cheirogaleids in dental structure and body size. Two genera from Oman, Omanodon and Shizarodon, also reveal a mix of similarities to both cheirogaleids and anchomomyin adapoids. Resolving the phylogenetic position of these Africa primates of the early Tertiary will surely require more and better fossils. By the early to middle Miocene, lorisoids were well established in East Africa, and the debate about whether these represent lorisines or galagines is reviewed. Neontological data are used to address the controversial branching sequences among extant lorisid clades. Data from the skin and scent glands, when integrated with other lines of evidence, suggest that Asian and African lorisines share a common lorisine ancestry. The hypothesis of an African clade containing both pottos and galagos to the exclusion of Asian lorisines is less tenable. True galagines are found in the fossil record of Namibia, while true lorisines are known from the Miocene of Asia. The hypothetical branching sequences can be integrated with behavioral and morphological features to develop an adaptive model of lorisoid divergence. By specializing on two different foraging modes early in their radiation, lorisines and galagines subsequently underwent a chain of integrated evolutionary changes eventually having an impact on many components of locomotor behavior, anatomy, physiology, reproduction, life history, and social behavior. Ongoing evolutionary studies of extant galagines are illuminating population phenomena and processes of speciation in an ecological context.
The Evolution of Exudativory in Primates is the first edited volume to offer a comprehensive overview of this rare dietary niche in the primate order. Leading researchers in the field of primatology synthesize our current knowledge of the behavioral, socioecological, nutritional, morphological, and evolutionary aspects of exudate-feeding in primates. The Evolution of Exudativory in Primates covers exudate-feeding in callitrichines, callimicos, mouse lemurs, lorises, and galagos. Advances in our understanding of how these animals obtain their food and digest it, how this food resource affects social relationships, and how morphology is related to exudate-feeding are presented in subsequent essays. The final chapter synthesizes current data on what role exudate-feeding may have played in the earliest primates, the plesiadapiforms, and what exudate-feeding signals may be present in the fossil record. Ideal for upper-level undergraduate and graduate primatology courses, The Evolution of Exudativory in Primates can also be used for courses in biology, comparative mammalogy, and conservation. About the Editors: ANNE M. BURROWS is an Associate Professor in the Department of Physical Therapy at Duquesne University and a Research Associate Professor in the Department of Anthropology at the University of Pittsburgh. She has worked on the functional and evolutionary morphology of the primate craniofacial complex with a focus on strepsirrhines. LEANNE T. NASH is a Professor of Anthropology in the School of Human Evolution and Social Change at Arizona State University. She has worked extensively with a captive colony of Galago senegalensis held previously at ASU for 20 years. She has also done fieldwork in Africa and Madagascar on baboons, galagos, and sportive lemurs. Other collaborations have been on captive chimpanzee behavior with the Primate Foundation of Arizona.
Throughout much of Asia slow lorises (Nycticebus) and tarsiers (Tarsius) live allopatrically but on several islands they occur in sympatry. As habitats dwindle, competition for resources may increase within the area of sympatry. An understanding of how they are coping with competition is necessary for conservation measures. To address this we gathered data on the abundances and vertical strata preferences of slow loris and tarsier species from the literature. We predict sympatric species will favour different heights from congeners. Allopatric species will have lower abundances compared to sympatric species. In addition, we studied tarsiers and lorises in sympatry in Sabah, Borneo. We estimated abundances of Bornean lorises (Nycticebus menagensis) and Western tarsiers (Tarsius bancanus borneanus) and investigated habitat use. Through the literature review we found lorises do not vary in densities, whether allopatric or sympatric. Abundances of sympatric and allopatric tarsiers were significant (sympatric: 3-27 individuals/km2, allopatric: 57-268 individuals/ km2). Vertical strata use of sympatric and allopatric tarsier populations was not significant, but was for sympatric and allopatric loris populations (p=0.036). On a small scale estimated densities of Bornean lorsies were 5.105 slow lorises/km² and 3.646 individuals/km² for Western tarsiers. Slow lorises favoured the upper and middle level of the forest (10-30 m) and tarsiers the lower levels (<5 m). In our analysis of vegetation plots we found that tree heights and diameter at breast height preferences differed between genera. Results indicate sympatric genera are able to share their nocturnal environment due to niche separation.
Despite a large geographic distribution, the African nocturnal perodicticines, pottos (Perodicticus) and angwantibos (Arctocebus ) remain amongst the least studied primate taxa. Only two one-year field studies have been conducted on pottos, with only circumstantial data onangwantibos, coming from field data on shot animals. Through a meta-analysis, based on published literature and unpublished reports, we here review recent skeletal and genetic evidence that point to five species, and indicate far more diversity: Perodicticus potto, P. Ibeanus, P. edwardsi, Arctocebus aureus, A. calabarensis. Pelage colour, dorsal markings and tail characteristics (for pottos) supplement the genetic data that suggest these comprise distinct taxa. Arctocebus ranges from Nigeria and Cameroon in the north to Gabon and Congo in the south, whilst Perodicticus is more widespread, having a combined distribution that encompasses a large portion of central and western Africa. Despite this large range, only nine surveys with any substantial effort have been published in the last twenty years from only five range countries; two re-ported new taxa (P. p. stockleyi and P. p. juju). Although not included in abundance counts,pottos frequently appear in bushmeat reports throughout their range, suggesting this is a realthreat to this cryptic, easy-to-catch primate. Despite an almost complete dearth of knowledgeabout these taxa, all perodicticine taxa are listed on the IUCN Red List of Threatened Species as Least Concern, with, contradictorily, only the reasonably studied P. p. stockleyi as Data Deficient. The situation of these primates is mirrored in zoos. No Arctocebus are kept in European zoos, with only 17 Perodicticus in ISIS institutions. Their taxonomy is uncertain, breeding rates are poor and infant mortality is high. Clearly the perodictines offer an open frontier for both in situ and ex situ studies. We certainly do not have the data to assess their conservation status yet.