Assessing habitat utilization by neotropical primates: a new approach

This study aims to ascertain habitat utilization, in relation to forest structural variation, by a multi-species group of primates in tropical lowland rainforest in Southeast Peru during dry season. A new approach to assessing habitat utilization was used. Habitat variation was described by structural and indicator variables collected in quadrats along transects through a study area within Terra Firme and Floodplain forest. Variables were grouped into ‘factors’ accounting for most of the variation by means of a Principal Components Analysis (PCA). Presence or absence of the primates within the quadrats, assessed by repeat transect surveys, was taken to indicate habitat preferences. Discrimination between the habitat and forest structure in areas of primate presence as opposed to absence was carried out by means of Discriminant Function Analysis (DFA). This highlighted patterns in most utilized habitat. Vertical utilization of the forest was also assessed along with presence in bamboo and general activity on encounter. Suggestions of habitat preference and utilization are made for each of the six sympatric species studied, based on significantly discriminating habitat factors, vertical stratification on encounter and relationships with bamboo.Saguinus fuscicollis andCebus moloch appeared as habitat generalists.Cebus apella, Saimiri sciureus, andAotus spp., exhibited varying degrees of preference for habitat factors suggesting disturbed forest,Cebus albifrons was more generalistic but with a possible association with primary, naturally disturbed forest.C. appella was encountered in Terra Firme forest significantly more than in Floodplain. ForS. sciureus, C. moloch, andC. apella, upper understory was the most utilized forest layer, forC. albifrons, middle canopy and forS. sciureus andAotus spp., lower understory. Both positive and negative relationships with bamboo were highlighted. Significant positive relationships betweenAotus spp., and bamboo suggest dense bamboo stands provide important daytime resting sites for this nocturnal species.C. moloch was also shown to utilize bamboo whereasS. fuscicollis appeared to actively avoid it. High levels of conformity with past studies in terms of habitat utilization patterns described for the species studied supports the conclusion that the methods used in this study provide an effective means of assessing primate habitat utilization within complex habitat.     

Comparison of responses to alarm calls by patas (Erythrocebus patas) and vervet (Cercopithecus aethiops) monkeys in relation to habitat structure

We studied responses to alarm calls of sympatric patas (Erythrocebus patas) and vervet (Cercopithecus aethiops) monkeys in relation to habitat structure, with the intention of understanding the relationship between the environment and predator avoidance. Patas and vervet monkeys are phylogenetically closely related and overlap in body size. However, while patas monkeys are restricted to nonriverine habitats at our study site, vervets use both nonriverine and riverine habitats, allowing us to "vary" habitat structure while controlling for effects of group size, composition, and phylogeny. Patas monkeys in the nonriverine habitat responded to mammalian predator alarm calls with a greater variety of responses than did vervets in the riverine habitat, but not when compared with vervets in the nonriverine habitat. Ecological measurements confirm subjective assessments that trees in the riverine habitat are significantly taller and occur at lower densities than trees in the nonriverine habitat. Despite the lower density of trees in the riverine habitat, locomotor behavior of focal animals indicates that canopy cover is significantly greater in the riverine than the nonriverine habitat. Differences in responses to alarm calls by the same groups of vervets in different habitat types, and convergence of vervets with patas in the same habitat type, suggest that habitat type can be a significant source of variation in antipredator behavior of primates.     

Nonhuman Primates in the Namdapha National Park, Arunachal Pradesh, India

Namdapha National Park and Tiger Reserve in the Changlang District of Arunachal Pradesh in northeastern India are rich in biodiversity. The dense evergreen forest of the park with high canopy coverage supports a variety of fauna including primates. In February, 2002, we surveyed the primates in Namdapha National Park to assess their status. We directly sighted, 5 species of diurnal primates, and secondary information shows the presence of stump-tailed macaques and slow lories. We encountered 10 groups of hoolock gibbons (33 individuals), 9 troops of capped langurs (61 individuals), 15 groups of Assam macaques (209 individuals), 6 groups of rhesus macaques (74 individuals) and one unidentified group of macaques (15 individuals). Hunting, rather than habitat destruction, is the chief potential threat for primates in the park.     

Seasonality in the Ecology and Life Histories of Mountain Gorillas (Gorilla gorilla beringei)

The abundance of food, especially that of fruit and often that of young leaves, varies considerably over time for most primates. This variation can depend on or be independent of seasonality in rainfall. Mountain gorillas (Gorilla gorilla beringei) in the Virungas are exceptional: their habitat contains almost no edible fruit, and they mostly eat perennially available herbs and vines that are densely and evenly distributed in much of their habitat. Earlier studies documented little consistent temporal variation in mountain gorilla diets and habitat use, except for seasonal use of bamboo by some groups, and documented no birth seasonality. Long-term data ( 7 years) on 6 mountain gorilla groups confirm these results for habitat use, except that they show some seasonality in use of the upper altitudinal extremes of the gorillas' home ranges for unclear reasons. Relatively low and inconsistent variation in habitat quality over time should lower the costs of grouping for gorillas compared to other apes. Long-term data also confirm the absence of seasonality in births and conceptions. However, they show that mortality rates and risk of respiratory infections vary directly with rainfall. These relationships are probably causal and may be mediated through thermoregulatory stress.     

Resource use of Japanese macaques in heavy snowfall areas: implications for habitat management

Populations of Japanese macaque (Macaca fuscata) that inhabit the northernmost distribution of any nonhuman primates have been listed as endangered in Japan; however, macaques are widely known for being pests that cause agricultural damage. This study identified priority areas for the conservation and management of macaque habitats, by comparing the resource use of troops occupying remote mountains (montane troops) against troops inhabiting disturbed forests adjacent to settlements (rural troops). We collected species presence data across 2 years by radio-tracking two montane troops and two rural troops in the Shirakami Mountains. We developed seasonal utilization distributions by using the kernel method, and identified habitat characteristics by using ecological-niche factor analysis (ENFA). Our results indicate that environmental factors influencing the potential habitat varied widely with season in montane troops as compared with that in rural troops. ENFA results demonstrated that rural troops exhibited more biased resource use and narrower niche breadths than montane troops. Based on our findings, we propose that (1) primary broadleaf forests are the spring habitat conservation priority of montane troops; (2) the habitat unit—the product of habitat suitability index and its surface area—for montane troops is enhanced by removing old conifer plantations from the forest edge at low elevations; (3) such removal around settlements may also contribute toward removing a frontline refuge for rural troops intruding farmlands; and (4) intensive prevention measures against macaque intrusions into settlements during the bottleneck snowy season contribute toward reducing the habitat unit of rural troops.     

Habitat use of Bornean Orangutans (<Emphasis Type="Italic">Pongo pygmaeus morio</Emphasis>) in an Industrial Forestry Plantation in East Kalimantan,Indonesia

Many primates now live in anthropogenic landscapes dominated by human activity such as agriculture. Conserving primates in such contexts requires detailed information about habitat use, including landscape features that may influence population viability. We studied Northeast Bornean orangutan (Pongo pygmaeus morio) habitat use in a forestry plantation in East Kalimantan, Indonesia. We conducted camera trapping and nest surveys at 13 locations across three habitat types in the plantation (planted acacia stands, planted eucalyptus stands, and secondary forest patches left uncut or allowed to regenerate) September 2012–March 2013, and calculated four measures of orangutan abundance for each location (independent photo captures/100 camera trap days, or RAI₂; nest encounter rate; nest density; and orangutan density). Orangutans are relatively common in the plantation; they used all three habitat types and exhibited a higher RAI₂ than 70% of other mammal species detected. A logistic regression found that proximity to natural forest areas best predicted orangutan abundance calculated using camera trap data (RAI₂) but that habitat type combined with distance to natural forest best predicted orangutan abundance calculated using nest counts. This suggests that orangutans use planted areas for movement and feeding, but rely on patches of natural forest for resting and access to key resources. Our study and others indicate that orangutans can coexist with some human activities if provided with sufficient access to natural forest. However, we must conduct further research to facilitate effective conservation planning, including gathering additional details about habitat and resource use and possible long-term population impacts.     

Theoretical habitat templets, species traits, and species richness: Trichoptera in the Upper Rhône River and its floodplain

• 1 For Trichoptera occurring in two sites of the Upper Rhône River (France) we examine: (i) relationships among species traits; (ii) habitat utilization of Trichoptera species; (iii) the relationship between species traits and habitat utilization; (iv) trends of species traits in the framework of spatial–temporal habitat variability to test predictions of the habitat templet concept; and (v) trends of species richness in the framework of spatial–temporal habitat variability to test predictions of the patch dynamics concept.
• 2 Of the sixteen species traits selected, twelve have high correlation ratios for the seventy-five species used in this analysis; these traits are related to behavioural, morphological, or physiological aspects. Traits related to reproduction or life cycle have lower correlation ratios.
• 3 An ordination by species traits separates the five main families into three groups: (i) Hydropsychidae and Polycentropodidae; (ii) Hydroptilidae; and (iii) Leptoceridae and Limnephilidae. An ordination of the habitat utilization of the species in ten habitats indicates that the Hydropsychidae occur preferentially in the main channel, Hydroptilidae, Polycentropodidae, and Limnephilidae occur in backwaters or oxbow lakes, and the Leptoceridae are ubiquitous.
• 4 The Hydropsychidae exhibit a relationship between species traits and habitat utilization, i.e. they use similar habitat types with similar species traits. The species traits of the other four families are similar but their habitat utilization is quite different.
• 5 The Hydropsychidae occur in lowest spatial–temporal variability habitats and Limnephilidae in the highest. Therefore, net spinners and filterers are characteristic of habitats with a low spatial–temporal variability, whereas shredders and case makers using plant material are characteristic of habitats with high spatial–temporal variability. The trends in species traits show little agreement with trends predicted from the river habitat templet.
• 6 Trends of species richness in the framework of spatial and temporal variability do not follow the predictions of the patch dynamics concept because richness is similar in all superficial habitats. This implies that each habitat, in spite of large differences in their spatial and temporal variability, offers Trichoptera a similar but limited number of ecological niches.

     

Response to Darting Primates: Steps toward Procedural and Reporting Standards

The safety of primates which are captured and released in the wild is a topic of concern for many field primatologists. Our article and the recent commentary by Fernandez-Duque et al. contribute to the discussion. Although Fernandez-Duque et al. found a slightly higher rate of fatalities (2.5 %) than Cunningham et al. (2.0 %), their combined rate of fatal and serious injuries was lower (4.0 % vs 5.0 %). The differences in rate are not substantial, given limitations of the data. However, as Fernandez-Duque et al. highlight the need for standardizing methods of analysis, we believe the methods they suggest merit careful consideration. We agree that variation in size, habitat, and the experience of the darting team are important factors. Cunningham et al. reported the influence of these factors on injury and fatality rates. There are, however, some important differences in the methods of Cunningham et al. and Fernandez-Duque et al. We believe it is important to 1) acknowledge possible bias in the data, 2) report results of serious complications that arise during capture, 3) report results of capturing medically compromised primates, and 4) report rates of primates falling to the ground.     

Theoretical habitat templets, species traits, and species richness: aquatic oligochaetes in the Upper Rhône River and its floodplain

• 1 This paper summarizes twenty years of ecological research on aquatic oligochaetes of the Upper Rhône River and its alluvial floodplain (France). Species traits of fifty species of the ninety taxa recorded from two areas Gons and Brégnier-Cordon) were used to examine the relationships among species traits, habitat utilization of these species, whether a relationship exists between species traits and habitat utilization, and the applicability of predictions from the river habitat templet and the patch dynamics concept in the framework of spatial and temporal habitat variability. We used fourteen habitat types and sixteen species traits in this analysis.
• 2 When examined by correspondence analysis, species traits separate the Naididae (with a higher potential for reproduction, small size, high mobility, and opportunistic diet) from all other families.
• 3 Habitat utilization by oligochaetes demonstrates two gradients: a vertical gradient that arranges species by their affinity for interstitial habitats (stygophily) and a transversal gradient that arranges them by their affinity for main channel habitats (rheophily).
• 4 No significant relationship was found between species traits and habitat utilization in a co-inertia analysis.
• 5 Trends observed for species traits within the framework of spatial-temporal habitat variability show only minor agreement with predictions of the river habitat templet.
• 6 Species richness is generally higher in superficial and interstitial habitats that are permanently connected with the main channel, and peaks in the superficial parapotamons (backwaters that are permanently connected with the main channel) characterized by intermediate levels of spatial as well as temporal variability; this pattern only partially fits with predictions of the patch dynamics concept.

     

Distribution and Forest Utilization of Saguinus and Other Primates of the Pando Department, Northern Bolivia

We carried out a 4-month census of primates in the Pando Department of northern Bolivia with special emphasis on Saguinus species. Contrary to a previous report by Izawa and Bejarano (1981), there was no evidence for the presence of the two populations of Saguinus mystax that they reported, or that Lagothrix occurs in the Pando. In addition, we found the distribution of Saguinus imperator to be more restricted than they suggested. We confirm the presence of Cebuella south of the Río Tahuamanu (cf. Brown and Rumiz, 1986) and report two new locations for Callimico goeldii. We present data on group sizes, habitat utilization, and locomotor behavior of the primates and compare them with previous studies in the Pando. Differences in body size, diet, foraging techniques, and vertical use of the forest appear to be key factors in both sympatry and in the formation of polyspecific associations.     

Positional behavior and body size of arboreal primates: a theoretical framework for field studies and an illustration of its application.

The rationale for most field studies of the positional behavior of arboreal primates has been the need to document natural behaviors quantitatively in order to infer the functional significance of morphological configurations. This focus on interactions of morphology with behavior is justifiable, but there exists another important level of biological relationships, that of the animal with its structural habitat, which it must negotiate to find food and avoid being preyed on. Recently it has become apparent that body size is likely to affect relationships of positional behavior with habitat structure, as well as with morphology. Here I offer a framework for research on functional relationships of positional behavior, body size, and habitat structure, with the ultimate objective of elucidating the aptive significance of the great diversity exhibited by arboreal primates. This approach specifies several distinct problems that animals solve, and indicates how research might be directed at revealing the relative effectiveness with which different primates solve them. A preliminary application of the framework examines sympatric north Sumatran primates.     

A global risk assessment of primates under climate and land use/cover scenarios

Primates are facing an impending extinction crisis, driven by extensive habitat loss, land use change and hunting. Climate change is an additional threat, which alone or in combination with other drivers, may severely impact those taxa unable to track suitable environmental conditions. Here, we investigate the extent of climate and land use/cover (LUC) change‐related risks for primates. We employed an analytical approach to objectively select a subset of climate scenarios, for which we then calculated changes in climatic and LUC conditions for 2050 across primate ranges (N = 426 species) under a best‐case scenario and a worst‐case scenario. Generalized linear models were used to examine whether these changes varied according to region, conservation status, range extent and dominant habitat. Finally, we reclassified primate ranges based on different magnitudes of maximum temperature change, and quantified the proportion of ranges overall and of primate hotspots in particular that are likely to be exposed to extreme temperature increases. We found that, under the worst‐case scenario, 74% of Neotropical forest‐dwelling primates are likely to be exposed to maximum temperature increases up to 7°C. In contrast, 38% of Malagasy savanna primates will experience less pronounced warming of up to 3.5°C. About one quarter of Asian and African primates will face up to 50% crop expansion within their range. Primary land (undisturbed habitat) is expected to disappear across species' ranges, whereas secondary land (disturbed habitat) will increase by up to 98%. With 86% of primate ranges likely to be exposed to maximum temperature increases >3°C, primate hotspots in the Neotropics are expected to be particularly vulnerable. Our study highlights the fundamental exposure risk of a large percentage of primate ranges to predicted climate and LUC changes. Importantly, our findings underscore the urgency with which climate change mitigation measures need to be implemented to avert primate extinctions on an unprecedented scale.     

Habitat characterization of western hoolock gibbons Hoolock hoolock by examining home range microhabitat use

Conserving a species depends on an understanding of its habitat requirements. Primatologists often characterize the habitat requirements of primates using macroscale population-based approaches relying on correlations between habitat attributes and population abundances between sites with varying levels of disturbance. This approach only works for species spread between several populations. The populations of some primates do not fulfill these criteria, forcing researchers to rely on individual-based (microscale) rather than population-based approaches for habitat characterization. We examined the reliability of using micro-scale habitat characterizations by studying the microhabitat preferences of a group of wild western hoolock gibbons (Hoolock hoolock) in order to compare our results to the habitat preferences of western hoolock gibbons identified during a macroscale study of populations across Bangladesh. We used stepwise discriminant analysis to differentiate between the areas of low, medium, and high usage based on microhabitat characteristics (tree species availability, altitude, canopy connection, distance from forest edge, and levels of human disturbance). The gibbons used interior forest habitat with low food tree availability most frequently for sleeping and socializing, and used edge habitat containing high food tree availability for medium periods for feeding. These results indicate that the gibbons prefer interior forest but are frequently forced to visit the forest edge to feed. Therefore, the optimal habitat would be interior forest away from human disturbance with high sleeping-tree and feeding-tree availability. These habitat preferences are consistent with the habitat attributes of Bangladesh’s largest remaining western hoolock gibbon populations, which live in areas containing low agricultural encroachment and high food-tree availability. Microhabitat use studies can be used to characterize the habitat requirements of a species, but should include multiple scales of analysis wherever possible.     

What is dental ecology?

Teeth have long been used as indicators of primate ecology. Early work focused on the links between dental morphology, diet, and behavior, with more recent years emphasizing dental wear, microstructure, development, and biogeochemistry, to understand primate ecology. Our study of Lemur catta at the Beza Mahafaly Special Reserve, Madagascar, has revealed an unusual pattern of severe tooth wear and frequent tooth loss, primarily the result of consuming a fallback food for which these primates are not dentally adapted. Interpreting these data was only possible by combining our areas of expertise (dental anatomy [FC] and primate ecology [MS]). By integrating theoretical, methodological, and applied aspects of both areas of research, we adopted the term "dental ecology"-defined as the broad study of how teeth respond to the environment. Specifically, we view dental ecology as an interpretive framework using teeth as a vehicle for understanding an organism's ecology, which builds upon earlier work, but creates a new synthesis of anatomy and ecology that is only possible with detailed knowledge of living primates. This framework includes (1) identifying patterns of dental pathology and tooth use-wear, within the context of feeding ecology, behavior, habitat variation, and anthropogenic change, (2) assessing ways in which dental development and biogeochemical signals can reflect habitat, environmental change and/or stress, and (3) how dental microstructure and macro-morphology are adapted to, and reflect feeding ecology. Here we define dental ecology, provide a short summary of the development of this perspective, and place our new work into this context.     

Nutritional Characteristics of Wild and Cultivated Foods for Chimpanzees (<Emphasis Type="Italic">Pan troglodytes</Emphasis>) in Agricultural Landscapes

Primate habitats are being transformed by human activities such as agriculture. Many wild primates include cultivated foods (crops) in their diets, calling for an improved understanding of the costs and benefits of crop feeding. We measured the macronutrient and antifeedant content of 44 wild and 21 crop foods eaten by chimpanzees (Pan troglodytes schweinfurthii) in a mosaic habitat at Bulindi, Uganda, to evaluate the common assertion that crops offer high nutritional returns compared to wild forage for primates. In addition, we analyzed 13 crops not eaten at Bulindi but that are consumed by chimpanzees elsewhere to assess whether nutritional aspects explain why chimpanzees in Bulindi ignored them. Our analysis of their wild plant diet (fruit, leaves, and pith) corresponds with previous chemical analyses of primate plant foods. Compared to wild food equivalents, crops eaten by the chimpanzees contained higher levels of digestible carbohydrates (mainly sugars) coupled with lower amounts of insoluble fiber and antifeedants. Cultivated fruits were relatively nutritious throughout the ripening process. Our data support the assumption that eating cultivated foods confers energetic advantages for primates, although crops in our sample were low in protein and lipids compared to some wild foods. We found little evidence that crops ignored by the chimpanzees were less nutritious than those that they did eat. Nonnutritional factors, e.g., similarity to wild foods, probably also influence crop selection. Whether cultivated habitats can support threatened but flexible primates such as chimpanzees in the long term hinges on local people’s willingness to share their landscape and resources with them.     

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.     

Theoretical habitat templets, species traits, and species richness: aquatic insects in the Upper Rhône River and its floodplain

• 1 For five orders of Insecta (Plecoptera, Ephemeroptera, Odonata, Trichoptera, and Coleoptera) in two sites of the Upper Rhône River (France), the following are examined: (i) relationships among nineteen species traits; (ii) habitat utilization of species; (iii) the relationship between species traits and habitat utilization; and (iv) trends of species traits and species richness in a templet of spatial-temporal habitat variability.
• 2 The species traits having the highest correlations correspond to reproduction, life cycle, nutritional, and morphological features. Species trait characteristics of Coleoptera are distinctly contrasted with those of Plecoptera and Ephemeroptera; Odonata and Trichoptera are intermediate to these orders.
• 3 The distribution of species in fourteen habitat types of the Upper Rhône River floodplain demonstrates a transverse gradient from the main channel to the oxbow lakes and the temporary water habitats, and a vertical gradient from interstitial to superficial habitats.
• 4 Despite a significant relationship between species traits and habitat utilization, superposition between species traits and habitat utilization is limited. At the order level, species form usually one (Ephemeroptera, Trichoptera, Odonata) or several (Coleoptera) groups of relatively homogeneous species traits; however, the species of each of these groups utilize rather different habitat types.
• 5 Only for some life history traits, e.g. the minimum age of reproduction or the number of reproductive cycles per year, do the trends observed in the framework of spatial—temporal variability of habitat types agree with the predictions from the river habitat templet. This mismatch mainly results from the unique phylogenetic history of the Coleoptera compared with that of the other four orders.
• 6 Species richness peaks at an intermediate level of temporal variability; however, it does not gradually increase with increasing spatial variability, nor increase from low to intermediate temporal variability.

     

Conceptualization and Measurement of Habitat Fragmentation from the Primates’ Perspective

Habitat fragmentation is one of the principal threats to primates. Studies of primates in fragments usually conclude that fragmentation negatively affects some aspect of their biology or ecology. Nevertheless, the definition and quantification of fragmentation vary considerably among studies, resulting in contradictions and results that are difficult to interpret. We here 1) discuss the problems associated with the definition of habitat fragmentation and the ways of measuring it, 2) emphasize the importance of the concepts and methods from landscape ecology and metapopulation theory for the study of primates in fragmented landscapes, and 3) offer recommendations for more precise use of concepts associated with habitat fragmentation from the primates’ perspective. When specific knowledge of the study species/population is available, we suggest that the definition of the variables to be measured should be functional from the primates’ perspective, based, e.g., on their habitat requirements and dispersal capacity. The distance to the nearest fragment may not be the best way to measure the isolation between populations. Fragmentation per se is a landscape scale process and, hence, landscape scale studies are required to understand how species are distributed across heterogeneous landscapes. Finally, it is important to consider that what happens at the fragment scale could be the consequence of processes that interact at various spatial and temporal scales.     

A theory on the evolution of the habitual orthograde human bipedalism--the "Amphibische Generalistentheorie"

The theory is formulated that ubiquitous scarcity of energy is one of the main motors of evolution. It is concluded that our primate ancestors never came down from the trees, but rather they have always been (semi-)terrestrial. This habit is probably an old symplesiomorph trait, older than primates themselves. Terrestrial habits in primates correlate to body weight in small systematic groups (e.g., large genera, families) but are, overall, completely independent from individual body mass. An omnivorous, semiterrestrial quadrupedal locomotor generalist seems to be the most probable morpho- and eco-type for our ancestor at the threshold of a hominoid stage of our evolution. The theory presented here suggests that our hominoid ancestor lived in gallery forests and changed strata in order also to inhabit the savannah habitat as well as the shallow water of the rivers or coasts. Foraging in a wading manner was extremely favourable for an effective and, especially, seasonally independent, animal protein supply. Anatomical adaptations to orthogradism and proportions of the extremities are discussed in relation to the necessary and frequent change of habitat strata. Ultimately, human bipedalism is seen here to be derived as a consequence of the centre of body mass, which is, in primates, near the hind extremities. By contrast to other mammals entering the water, wading primates sink back on their hind limbs. Selective forces for habitat use, limb proportions and wading habits are discussed, as well as the phylogenetic origin of human affinity to water and shores in all peoples through all times, from australopithecine times through the Paleolithic until today.     

Activity and Habitat Use of Chimpanzees (<Emphasis Type="Italic">Pan troglodytes verus</Emphasis>) in the Anthropogenic Landscape of Bossou,Guinea, West Africa

Many primate populations inhabit anthropogenic landscapes. Understanding their long-term ability to persist in such environments and associated real and perceived risks for both primates and people is essential for effective conservation planning. Primates in forest–agricultural mosaics often consume cultivars to supplement their diet, leading to potentially negative encounters with farmers. When crossing roads, primates also face the risk of encounters with people and collision with vehicles. Chimpanzees (Pan troglodytes verus) in Bossou, Guinea, West Africa, face such risks regularly. In this study, we aimed to examine their activity budget across habitat types and the influence of anthropogenic risks associated with cultivated fields, roads, and paths on their foraging behavior in noncultivated habitat. We conducted 6-h morning or afternoon follows daily from April 2012 to March 2013. Chimpanzees preferentially used forest habitat types for traveling and resting and highly disturbed habitat types for socializing. Wild fruit and crop availability influenced seasonal habitat use for foraging. Overall, chimpanzees preferred mature forest for all activities. They showed a significant preference for foraging at >200 m from cultivated fields compared to 0–100 m and 101–200 m, with no effect of habitat type or season, suggesting an influence of associated risk. Nevertheless, the chimpanzees did not actively avoid foraging close to roads and paths. Our study reveals chimpanzee reliance on different habitat types and the influence of human-induced pressures on their activities. Such information is critical for the establishment of effective land use management strategies in anthropogenic landscapes.