Primate Abundance in an Unhunted Region of the Northern Peruvian Amazon and the Influence of Seismic Oil Exploration

The western Amazon, a relatively remote and unstudied region, is experiencing unprecedented levels of oil and gas exploration. Despite the widespread use of seismic reflection technology for oil and gas exploration, no studies have investigated the response of primate populations to this disturbance in the Amazon. We conducted distance sampling along transects in pristine, unhunted lowland rain forest inside a large oil concession (Block 39) in the northern Peruvian Amazon with ongoing 2D seismic exploration. We aimed to investigate seismic exploration effects on local primate abundance, with a particular focus on the region’s most endangered primates, lowland woolly monkeys (Lagothrix poeppigii) and white-bellied spider monkeys (Ateles belzebuth). We sampled transects before the arrival of exploration crews (control) and during the seismic operation (disturbance) and compared primate counts using mixed-effect models. We confirmed the presence of nine species of primates along sampled transects. Abundance of primate groups (species pooled) was not different between the control and disturbance period, yet abundance of primate individuals was significantly lower in the disturbance period. Although we encountered groups of Ateles belzebuth equally often during the control and disturbance periods, overall counts of individuals of this species were lower during the disturbance period owing to lower subgroup sizes. This suggests this species may have responded, at least temporarily, with localized spatial avoidance, and that it may be particularly sensitive to human disturbance regardless of hunting pressure. Our overall density estimate for Lagothrix poeppigii (30.6/km²) approaches the highest reported for the species. Although the relatively temporary nature of 2D seismic exploration may limit its effect on primate species, our data indicate some species may respond more negatively than others.     

The Hand That Feeds the Monkey: Mutual Influence of Humans and Rhesus Macaques (<Emphasis Type="Italic">Macaca mulatta</Emphasis>) in the Context of Provisioning

Historically, humans and other primates (primates henceforth) have coexisted across cultures and contexts, and many primate populations use anthropogenic food sources as their main or supplementary food. While primates may actively forage for such food, they are also directly provisioned by humans in many regions. Ethnoprimatology views humans and primates as cohabitants of integrated socioecological spaces who mutually influence each other’s ecologies and social lives. We contextualized provisioning of primates by humans within an ethnoprimatological framework and examined if the availability of anthropogenic food affected primate diets or the amount of time primates spent in anthropogenic habitats and whether primates influenced the human act of provisioning. To this end, we used scan sampling on a group of rhesus macaques across a year, and conducted interviews with 86 people who paused at a nearby tea shop for refreshments. We found that the macaques’ consumption of natural resources and dietary diversity decreased, and they spent more time in human-modified habitats when provisioned food was available. We also found that particular behaviors of the provisioned macaques stimulated provisioning by humans. Our findings show that provisioning influences macaque feeding ecology and habitat use, and that the behavior of the macaques themselves drives people to provide them with food subsidies, illustrating a complex web of interactions between the sympatric species.     

Distinguished primatologist address—moving from advocacy to activism: Changing views of primate field research and conservation over the past 40 years

Field studies of wild nonhuman primates have grown exponentially over the past 40 years and our knowledge of primate behavior, ecology, and social, and mating systems has expanded greatly. However, we are facing a major extinction crisis with some 60% of all primate species listed as threatened and more than 75% of species with declining populations. The primary factor driving primate population decline is human population increase, which over the past 50 years has resulted in the unsustainable conversion and degradation of natural landscapes for industrial agriculture, the production of nonagricultural commodities for international trade, pastureland for cattle, dam construction, fossil fuel exploration, mining, and the construction of road networks and infrastructure to support large urban centers. Recent ecological modeling predicts that by the end of the century, the four primate‐richest countries in the world will lose 32–78% of their existing primate habitat to agricultural expansion, and nine of the top 15 primate‐richest countries are expected to have 80–100% of their primate species extinct or threatened with extinction. If we are going to save the world's primates, the time to act is now! Not only should all primate field research include a strong conservation component, but in addition we must actively join with our professional societies, zoos and research facilities, universities, conservation organizations, concerned business leaders, global citizens, like‐minded political leaders, and grassroots organizations to inform, demand and direct governments, multinational corporations, and international organizations to engage in transformational change to protect biodiversity and seek environmental justice against those entities that actively destroy our planet. As the chief academic discipline dedicated to the study of primates, we must organize and collectively move from being advocates for primate conservation to becoming activists for primate conservation. This is a call to action.     

The nutritional value of feeding on crops: Diets of vervet monkeys in a humanized landscape

Anthropogenic influences have dramatically altered the environments with which primates interact. In particular, the introduction of anthropogenic food sources to primate groups has implications for feeding behaviour, social behaviour, activity budgets, demography and life history. While the incorporation of anthropogenic foods can be beneficial to primates in a variety of nutritional ways including increased energetic return, they also carry risks associated with proximity to humans, such as risk of being hunted, disease risk and risk of conflict. Given such risks, we initiated a 3‐year study where we sought to understand the underlying nutritional motivations for anthropogenic food resource use by vervet monkeys (Cercopithecus aethiops) in the humanized matrix surrounding the Nabugabo Field Station in central Uganda. Feeding effort, defined as proportion of feeding scans spent on anthropogenic food, was not associated with ripe fruit availability nor with crop availability as determined by phenological monitoring. Likewise, there was no difference in the protein, fibre, or lipid composition of crop food items compared to wild food items. Individuals spent less time feeding overall in months over the 3 years with a higher proportion of time spent feeding on crop foods, suggesting a potential benefit in terms of accessibility (reduction in the proportion of activity budget devoted to feeding).     

Putting the Spotlight on Internally Displaced Animals (IDAs): A Survey of Primate Sanctuaries in Africa,Asia, and the Americas

As anthropogenic activity makes deeper incursions into forests, fragmenting habitat, wildlife is forced into closer proximity to humans leading to increased incidences of human–wildlife conflict and wildlife displacement. These same incursions facilitate poaching for the commercial trade in dead and live animals. As a direct result, the number of sanctuaries and internally displaced animals (IDAs) in need of sanctuary placement and rehabilitation are increasing. We focus on internally displaced primates given the prevalence of primate‐focused facilities and anthropomorphic considerations surrounding this taxonomic group. Surveys were distributed globally to map the extent and range of native primate sanctuaries and species. Over 70 facilities care for more than 6,000 native primates comprising 64 species, with almost half listed as endangered or critically endangered. As not all sanctuaries were identified at the time of the survey distribution, we estimate that the actual number of facilities is closer to double this number with a captive population in excess of 10,000 individual primates. Native primate sanctuaries hold significant numbers of primates in long‐term captive care, with less than half (37%) identified as candidates for release. The surveyed sanctuary population accounts for 35% of the world's captive primates, as compared to ISIS‐registered (where ISIS is International Species Information System) zoological facilities, although we estimate that the actual population is closer to 58%. For some species, the sanctuary population represents the only population in captivity. We discuss the prevalence of range‐state sanctuaries and their primate populations, and issues surrounding their future development and management. Am. J. Primatol. 75:116‐134, 2013. © 2012 Wiley Periodicals, Inc.     

Recalculating route: dispersal constraints will drive the redistribution of Amazon primates in the Anthropocene

Climate change will redistribute the global biodiversity in the Anthropocene. As climates change, species might move from one place to another, due to local extinctions and colonization of new environments. However, the existence of permeable migratory routes precedes faunal migrations in fragmented landscapes. Here, we investigate how dispersal will affect the outcome of climate change on the distribution of Amazon's primate species. We modeled the distribution of 80 Amazon primate species, using ecological niche models, and projected their potential distribution on scenarios of climate change. Then, we imposed landscape restrictions to primate dispersal, derived from a natural biogeographical barrier to primates (the main tributaries of the Amazon river) and an anthropogenic constraint to the migration of many canopy‐dependent animals (deforested areas). We also highlighted potential conflict zones, i.e. regions of high migration potential but predicted to be deforested. Species response to climate change varied across dispersal limitation scenarios. If species could occupy all newly suitable climate, almost 70% of species could expand ranges. Including dispersal barriers (natural and anthropogenic), however, led to range expansion in only less than 20% of the studied species. When species were not allowed to migrate, all of them lost an average of 90% of the suitable area, suggesting that climate may become unsuitable within their present distributions. All Amazon primate species may need to move as climate changes to avoid deleterious effects of exposure to non‐analog climates. The effect of climate change on the distribution of Amazon primates will ultimately depend on whether landscape permeability will allow climate‐driven faunal migrations. The network of protected areas in the Amazon could work as ‘stepping stones’ but most are outside important migratory routes. Therefore, protecting important dispersal corridors is foremost to allow effective migrations of the Amazon fauna in face of climate change and deforestation.     

Agroecosystems and Primate Conservation in The Tropics: A Review

Agroecosystems cover more than one quarter of the global land area (ca. 50 million km²) as highly simplified (e.g. pasturelands) or more complex systems (e.g. polycultures and agroforestry systems) with the capacity to support higher biodiversity. Increasingly more information has been published about primates in agroecosystems but a general synthesis of the diversity of agroecosystems that primates use or which primate taxa are able to persist in these anthropogenic components of the landscapes is still lacking. Because of the continued extensive transformation of primate habitat into human‐modified landscapes, it is important to explore the extent to which agroecosystems are used by primates. In this article, we reviewed published information on the use of agroecosystems by primates in habitat countries and also discuss the potential costs and benefits to human and nonhuman primates of primate use of agroecosystems. The review showed that 57 primate taxa from four regions: Mesoamerica, South America, Sub‐Saharan Africa (including Madagascar), and South East Asia, used 38 types of agroecosystems as temporary or permanent habitats. Fifty‐one percent of the taxa recorded in agroecosystems were classified as least concern in the IUCN Red List, but the rest were classified as endangered (20%), vulnerable (18%), near threatened (9%), or critically endangered (2%). The large proportion of threatened primates in agroecosystems suggests that agroecosystems may play an important role in landscape approaches to primate conservation. We conclude by discussing the value of agroecosystems for primate conservation at a broad scale and highlight priorities for future research. Am. J. Primatol. 74:696‐711, 2012. © 2012 Wiley Periodicals, Inc.     

High density of white-faced capuchins (Cebus capucinus) and habitat quality in the Taboga Forest of Costa Rica

Across the globe, primates are threatened by human activities. This is especially true for species found in tropical dry forests, which remain largely unprotected. Our ability to predict primate abundance in the face of human activity depends on different species' sensitivities as well as on the characteristics of the forest itself. We studied plant and primate distribution and abundance in the Taboga Forest, a 516-ha tropical dry forest surrounded by agricultural fields in northwestern Costa Rica. We found that the density of white-faced capuchins (Cebus capucinus) at Taboga is 2–6 times higher than reported for other long-term white-faced capuchin sites. Using plant transects, we also found relatively high species richness, diversity, and equitability compared with other tropical dry forests. Edge transects (i.e., within 100 m from the forest boundary) differed from interior transects in two ways: (a) tree species associated with dry forest succession were well-established in the edge and (b) canopy cover in the edge was maintained year-round, while the interior forest was deciduous. Sighting rates for capuchins were higher near water sources but did not vary between the edge and interior forest. For comparison, we also found the same to be true for the only other primate in the Taboga Forest, mantled howler monkeys (Alouatta palliata). Year-round access to water might explain why some primate species can flourish even alongside anthropogenic disturbance. Forest fragments like Taboga may support high densities of some species because they provide a mosaic of habitats and key resources that buffer adverse ecological conditions.     

Primates and Cameras

Field-based primate studies often make population inferences using count-based indices (e.g., individuals/plot) or distance sampling; the first does not account for the probability of detection and thus can be biased, while the second requires large sample sizes to obtain precise estimates, which is difficult for many primate studies. We discuss photographic sampling and occupancy modeling to correct for imperfect detection when estimating system states and dynamics at the landscape level, specifically in relation to primate ecology. We highlight the flexibility of the occupancy framework and its many applications to studying low-density primate populations or species that are difficult to detect. We discuss relevant sampling and estimation procedures with special attention to data collection via photographic sampling. To provide tangible meaning to terminology and clarify subtleties, we use illustrative examples. Photographic sampling can have many advantages over observer-based sampling, especially when studying rare or elusive species. Combining photographic sampling with an occupancy framework allows inference to larger scales than is common in primate studies, addresses uncertainty due to the observation process, and allows researchers to examine questions of how landscape-level anthropogenic changes affect primate distributions.     

Spatial structure of reproductive success infers mechanisms of ungulate invasion in Nearctic boreal landscapes

1. Landscape change is a key driver of biodiversity declines due to habitat loss and fragmentation, but spatially shifting resources can also facilitate range expansion and invasion. Invasive populations are reproductively successful, and landscape change may buoy this success.
2. We show how modeling the spatial structure of reproductive success can elucidate the mechanisms of range shifts and sustained invasions for mammalian species with attendant young. We use an example of white‐tailed deer (deer; Odocoileus virginianus) expansion in the Nearctic boreal forest, a North American phenomenon implicated in severe declines of threatened woodland caribou (Rangifer tarandus).
3. We hypothesized that deer reproductive success is linked to forage subsidies provided by extensive landscape change via resource extraction. We measured deer occurrence using data from 62 camera traps in northern Alberta, Canada, over three years. We weighed support for multiple competing hypotheses about deer reproductive success using multistate occupancy models and generalized linear models in an AIC‐based model selection framework.
4. Spatial patterns of reproductive success were best explained by features associated with petroleum exploration and extraction, which offer early‐seral vegetation resource subsidies. Effect sizes of anthropogenic features eclipsed natural heterogeneity by two orders of magnitude. We conclude that anthropogenic early‐seral forage subsidies support high springtime reproductive success, mitigating or exceeding winter losses, maintaining populations.
5. Synthesis and Applications. Modeling spatial structuring in reproductive success can become a key goal of remote camera‐based global networks, yielding ecological insights into mechanisms of invasion and range shifts to inform effective decision‐making for global biodiversity conservation.

     

Technological Response of Wild Macaques (<Emphasis Type="Italic">Macaca fascicularis</Emphasis>) to Anthropogenic Change

Anthropogenic disturbances have a detrimental impact on the natural world; the vast expansion of palm oil monocultures is one of the most significant agricultural influences. Primates worldwide consequently have been affected by the loss of their natural ecosystems. Long-tailed macaques (Macaca fascilularis) in Southern Thailand have, however, learned to exploit oil palm nuts using stone tools. Using camera traps, we captured the stone tool behavior of one macaque group in Ao Phang-Nga National Park. Line transects placed throughout an abandoned oil palm plantation confirmed a high abundance of nut cracking sites. Long-tailed macaques previously have been observed using stone tools to harvest shellfish along the coasts of Thailand and Myanmar. The novel nut processing behavior indicates the successful transfer of existing lithic technology to a new food source. Such behavioral plasticity has been suggested to underlie cultural behavior in animals, suggesting that long-tailed macaques have potential to exhibit cultural tendencies. The use of tools to process oil palm nuts across multiple primate species allows direct comparisons between stone tool using nonhuman primates living in anthropogenic environments.     

The Implications of Primate Behavioral Flexibility for Sustainable Human–Primate Coexistence in Anthropogenic Habitats

People are an inescapable aspect of most environments inhabited by nonhuman primates today. Consequently, interest has grown in how primates adjust their behavior to live in anthropogenic habitats. However, our understanding of primate behavioral flexibility and the degree to which it will enable primates to survive alongside people in the long term remains limited. This Special Issue brings together a collection of papers that extend our knowledge of this subject. In this introduction, we first review the literature to identify past and present trends in research and then introduce the contributions to this Special Issue. Our literature review confirms that publications on primate behavior in anthropogenic habitats, including interactions with people, increased markedly since the 2000s. Publications concern a diversity of primates but include only 17% of currently recognized species, with certain primates overrepresented in studies, e.g., chimpanzees and macaques. Primates exhibit behavioral flexibility in anthropogenic habitats in various ways, most commonly documented as dietary adjustments, i.e., incorporation of human foods including agricultural crops and provisioned items, and as differences in activity, ranging, grouping patterns, and social organization, associated with changing anthropogenic factors. Publications are more likely to include information on negative rather than positive or neutral interactions between humans and primates. The contributions to this Special Issue include both empirical research and reviews that examine various aspects of the human–primate interface. Collectively, they show that primate behavior in shared landscapes does not always conflict with human interests, and demonstrate the value of examining behavior from a cost–benefit perspective without making prior assumptions concerning the nature of interactions. Careful interdisciplinary research has the potential to greatly improve our understanding of the complexities of human–primate interactions, and is crucial for identifying appropriate mechanisms to enable sustainable human–primate coexistence in the 21st century and beyond.     

Are local patterns of anthropoid primate diversity related to patterns of diversity at a larger scale?

Aims (1) To determine the relationship between local and regional anthropoid primate species richness. (2) To establish the spatial and temporal scale at which the ultimate processes influencing patterns of primate species coexistence operate. Location Continental landmasses of Africa, South America and Asia (India to China, and all islands as far south as New Guinea). Methods The local–regional species richness relationship for anthropoid primates is estimated by regressing local richness against regional richness (independent variable). Local richness is estimated in small, replicate local assemblages sampled in regions that vary in total species richness. A strong linear relationship is taken as evidence that local assemblages are unsaturated and local richness results from proportional sampling of the regional pool. An asymptotic curvilinear relationship is interpreted to reflect saturated communities, where strong biotic interactions limit local richness and local processes structure the species assemblage. As a further test of the assumption of local assemblage saturation, we looked for density compensation in high‐density local primate assemblages. Results The local–regional species richness relationship was linear for Africa and South America, and the slope of the relationship did not differ between the two continents. For Asia, curvilinearity best described the relationship between local and regional richness. Asian primate assemblages appear to be saturated and this is confirmed by density compensation among Asian primates. However, density compensation was also observed among African primates. The apparent assemblage saturation in Asia is not a species–area phenomenon related to the small size of the isolated islands and their forest blocks, since similar low local species richness occurs in large forests on mainland and/or peninsular Asia. Main conclusions In Africa and South America local primate assemblage composition appears to reflect the influence of biogeographic processes operating on regional spatial scales and historical time scales. In Asia the composition of primate assemblages are by‐and‐large subject to ecological constraint operating over a relatively small spatial and temporal scale. The possible local influence of the El Niño Southern Oscillations on the evolution and selection of life‐history characteristics among Asian primates, and in determining local patterns of primate species coexistence, warrants closer inspection.     

Predator–Primate Distribution,Activity, and Co-occurrence in Relation to Habitat and Human Activity Across Fragmented and Contiguous Forests in Northeastern Madagascar

Predator–primate interactions are understudied, yet predators have been shown to influence primate behavior, population dynamics, and spatial distribution. An understanding of these interactions is important for the successful management and conservation of these species. Novel approaches are needed to understand better the spatial relationships between predators and primates across changing landscapes. We combined photographic surveys of predators and humans with line-transect sampling of lemurs across contiguous and fragmented forests in Madagascar to 1) compare relative activity; 2) estimate probability of occupancy and detection; 3) estimate predator–primate and local people–primate co-occurrence; and 4) assess variables influencing these parameters across contiguous and fragmented forests. In fragmented (compared to contiguous) forest sites endemic predator and lemur activity were lower whereas introduced predator and local people activity were higher. Our two-species interaction occupancy models revealed a higher number of interactions among species across contiguous forest where predator and lemur occupancy were highest. Mouse lemurs show evidence of “avoidance” (SIF < 1.0) with all predator species (endemic and introduced) in contiguous forest whereas white-fronted brown lemurs show “attraction” (SIF > 1.0) with feral cats and local people in contiguous forest. Feral cats demonstrated the highest number of interactions with lemurs, despite their distribution being limited to only contiguous forest. Distance to forest edge and distance to nearby villages were important in predicting predator occupancy and detection. These results highlight the growing threat to endemic predators and lemurs as habitat loss and fragmentation increase throughout Madagascar. We demonstrate the effectiveness of a novel combination of techniques to investigate how predator species impact primate species across a gradient of forest fragmentation.     

Control, choice, and assessments of the value of behavioral management to nonhuman primates in captivity

Many people have devoted considerable effort to enhancing the environments of nonhuman primates in captivity. There is substantial motivation to develop experimental, analytical, and interpretational frameworks to enable objective measurements of the value of environmental enrichment/behavioral management efforts. The consumer-demand approach is a framework not frequently implemented in studies of nonhuman primate welfare but profitably used in studies of the welfare of nonhuman animals in agriculture. Preference studies, in which primates can voluntarily choose to socialize or to participate in training, may be the best current examples of a consumer-demand-like approach to assessing the effects of captive management strategies on primate welfare. Additional work in this area would be beneficial; however, there are potential ethical constraints on purposefully subjecting primates to adverse circumstances to measure their demand for a resource. Primate welfare researchers need to design consumer-demand studies with obstacles that will help measure the relative value of resources to captive primates without compromising the welfare they are attempting to evaluate and enhance.     

Control,Choice, and Assessments of the Value of Behavioral Management to Nonhuman Primates in Captivity

Many people have devoted considerable effort to enhancing the environments of nonhuman primates in captivity. There is substantial motivation to develop experimental, analytical, and interpretational frameworks to enable objective measurements of the value of environmental enrichment/behavioral management efforts. The consumer-demand approach is a framework not frequently implemented in studies of nonhuman primate welfare but profitably used in studies of the welfare of nonhuman animals in agriculture. Preference studies, in which primates can voluntarily choose to socialize or to participate in training, may be the best current examples of a consumer-demand-like approach to assessing the effects of captive management strategies on primate welfare. Additional work in this area would be beneficial; however, there are potential ethical constraints on purposefully subjecting primates to adverse circumstances to measure their demand for a resource. Primate welfare researchers need to design consumer-demand studies with obstacles that will help measure the relative value of resources to captive primates without compromising the welfare they are attempting to evaluate and enhance.     

Spatial Overlap Between People and Non-human Primates in a Fragmented Landscape

In western Uganda, the landscape surrounding Kibale National Park (KNP) contains households, trading centers, roads, fields, and forest fragments. The mosaic arrangement of these landscape features is thought to enhance human–primate interaction, leading to primate population declines and increased bi-directional disease transmission. Using a social–ecological systems research framework that captures the complexity of interaction among people, wildlife, and environment, we studied five forest fragments near KNP and conducted intensive on-the-ground mapping to identify locations of human–primate spatial overlap. Primate locations and human activities were distributed within, on the edges, and far beyond fragment borders. Analysis of shared spaces indicated that 5.5% of human space overlapped with primate spaces, while 69.5% of primate spaces overlapped with human spaces. Nearest neighbor analysis indicated that human activities were significantly spatially clustered within and around individual fragments, as were primate locations. Getis–Ord statistics revealed statistically significant “hotspots” of human activity and primate activity, but only one location where spatial overlap between humans and primates was statistically significant. Human activities associated with collecting fuelwood and other forest products were the primary drivers of human–primate overlap; however, primates also spent time outside of forest fragments in agricultural spaces. These results demonstrate that fragmented landscapes are not uniform with respect to human–primate overlap, and that the implications of human–primate interaction, such as primate population declines and possible cross-species disease transmission, are spatially aggregated.     

A global assessment of primate responses to landscape structure

Land‐use change modifies the spatial structure of terrestrial landscapes, potentially shaping the distribution, abundance and diversity of remaining species assemblages. Non‐human primates can be particularly vulnerable to landscape disturbances, but our understanding of this topic is far from complete. Here we reviewed all available studies on primates' responses to landscape structure. We found 34 studies of 71 primate species (24 genera and 10 families) that used a landscape approach. Most studies (82%) were from Neotropical forests, with howler monkeys being the most frequently studied taxon (56% of studies). All studies but one used a site‐landscape or a patch‐landscape study design, and frequently (34% of studies) measured landscape variables within a given radius from the edge of focal patches. Altogether, the 34 studies reported 188 responses to 17 landscape‐scale metrics. However, the majority of the studies (62%) quantified landscape predictors within a single spatial scale, potentially missing significant primate–landscape responses. To assess such responses accurately, landscape metrics need to be measured at the optimal scale, i.e. the spatial extent at which the primate–landscape relationship is strongest (so‐called ‘scale of effect’). Only 21% of studies calculated the scale of effect through multiscale approaches. Interestingly, the vast majority of studies that do not assess the scale of effect mainly reported null effects of landscape structure on primates, while most of the studies based on optimal scales found significant responses. These significant responses were primarily to landscape composition variables rather than landscape configuration variables. In particular, primates generally show positive responses to increasing forest cover, landscape quality indices and matrix permeability. By contrast, primates show weak responses to landscape configuration. In addition, half of the studies showing significant responses to landscape configuration metrics did not control for the effect of forest cover. As configuration metrics are often correlated with forest cover, this means that documented configuration effects may simply be driven by landscape‐scale forest loss. Our findings suggest that forest loss (not fragmentation) is a major threat to primates, and thus, preventing deforestation (e.g. through creation of reserves) and increasing forest cover through restoration is critically needed to mitigate the impact of land‐use change on our closest relatives. Increasing matrix functionality can also be critical, for instance by promoting anthropogenic land covers that are similar to primates' habitat.     

What,where and when: spatial foraging decisions in primates

When exploiting the environment, animals have to discriminate, track, and integrate salient spatial cues to navigate and identify goal sites. Actually, they have to know what can be found (e.g. what fruit), where (e.g. on which tree) and when (in what season or moment of the year). This is very relevant for primate species as they often live in seasonal and relatively unpredictable environments such as tropical forests. Here, we review and compare different approaches used to investigate primate spatial foraging strategies: from direct observations of wild primates to predictions from statistical simulations, including experimental approaches on both captive and wild primates, and experiments in captivity using virtual reality technology. Within this framework, most of these studies converge to show that many primate species can (i) remember the location of most of food resources well, and (ii) often seem to have a goal‐oriented path towards spatially permanent resources. Overall, primates likely use mental maps to plan different foraging strategies to enhance their fitness. The majority of studies suggest that they may organise spatial information on food resources into topological maps: they use landmarks to navigate and encode local spatial information with regard to direction and distance. Even though these studies were able to show that primates can remember food quality (what) and its location (where), still very little is known on how they incorporate the temporal knowledge of available food (when). Future studies should attempt to increase our understanding of the potential of primates to learn temporal patterns and how both socio‐ecological differences among species and their cognitive abilities influence such behavioural strategies.     

Hybridization effects and genetic diversity of the common and black‐tufted marmoset (Callithrix jacchus and Callithrix penicillata) mitochondrial control region

Hybridization is continually documented in primates, but effects of natural and anthropogenic hybridization on biodiversity are still unclear and differentiating between these contexts remains challenging in regards to primate evolution and conservation. Here, we examine hybridization effects on the mitochondrial DNA (mtDNA) control region of Callithrix marmosets, which provide a unique glimpse into interspecific mating under distinct anthropogenic and natural conditions. DNA was sampled from 40 marmosets along a 50‐km transect from a previously uncharacterized hybrid zone in NE Brazil between the ranges of Callithrix jacchus and Callithrix penicillata. DNA was also collected from 46 marmosets along a 30‐km transect in a hybrid zone in Rio de Janeiro state, Brazil, where exotic marmosets appeared in the 1980s. Combining Callithrix DNA sampled inside and outside of these hybrid zones, phylogenetic and network analyses show C. jacchus and C. penicillata being parental species to sampled hybrids. We expand limited Callithrix population genetics work by describing mtDNA diversity and demographic history of these parental species. We show ancient population expansion in C. jacchus and historically constant population size in C. penicillata, with the latter being more genetically diverse than the former. The natural hybrid zone contained higher genetic diversity relative to the anthropogenic zone. While our data suggest hybrid swarm formation within the anthropogenic zone due to removed physical reproductive barriers, this pattern is not seen in the natural hybrid zone. These results suggest different genetic dynamics within natural and anthropogenic hybridization contexts that carry important implications for primate evolution and conservation. Am J Phys Anthropol 155:522–536, 2014. © 2014 Wiley Periodicals, Inc.