Distribution by Scientific Domains

Kinds of Chimpanzees

  • adult chimpanzee
  • captive chimpanzee
  • common chimpanzee
  • wild chimpanzee

  • Terms modified by Chimpanzees

  • chimpanzee genome
  • chimpanzee population

  • Selected Abstracts

    Temperature's influence on the activity budget, terrestriality, and sun exposure of chimpanzees in the Budongo Forest, Uganda

    Valerie P. Kosheleff
    Abstract Chimpanzee (Pan troglodytes schweinfurthii) activity budget, terrestriality, and sun exposure were found to be influenced by the immediate environmental temperature. Thirty adult chimpanzees in the Budongo Forest, Uganda, were observed for 247 h. Temperatures in the shade and sun, sky cover, sun exposure, activity, and terrestriality were recorded at 5-min intervals at <15 m from the center of the party. Terrestriality frequency was 26.5% for females and 41.5% for males. Terrestriality and resting both show a significant positive correlation with temperature in the sun. Controlling for seven potential confounding factors, temperature in the sun remained the strongest predictor of terrestriality. The difference between temperatures in the sun and shade had a significant effect on chimpanzee sun exposure frequency. Time spent continuously in the sun was negatively correlated with temperature, beginning to decrease around 30°C, and markedly decreasing around 40°C. A concurrent experiment determined that dark pelage (lacking physiological coping mechanisms) exposed to the same solar regime can easily reach 60°C within minutes. This study indicates that both temperature in the sun and sun exposure play a role in influencing chimpanzee activity behavior, and specifically suggests that chimpanzees thermoregulate behaviorally both by moving to the ground and by decreasing their activity level. These results, in the context of deforestation and increasing global temperatures, have physiological and conservation implications for wild chimpanzees. Am J Phys Anthropol, 2009. © 2008 Wiley-Liss, Inc. [source]

    A New Entodiniomorphid Ciliate, Troglocorys cava n. g., n. sp., from the Wild Eastern Chimpanzee (Pan troglodytes schweinfurthii) from Uganda

    ABSTRACT. Troglocorys cava n. g., n. sp. is described from the feces of wild eastern chimpanzee, Pan troglodytes schweinfurthii, in Uganda. This new species has a spherical body with a frontal lobe, a long vestibulum, a cytoproct located at the posterior dorsal side of the body, an ovoid macronucleus, a contractile vacuole near the cytoproct, and a large concavity on the left surface of the body. Buccal ciliature is non-retractable and consists of three ciliary zones: an adoral zone surrounding the vestibular opening, a dorso-adoral zone extending transversely at the basis of the frontal lobe, and a vestibular zone longitudinally extending in a gently spiral curve to line the surface of the vestibulum. Two non-retractable somatic ciliary zones comprise arches over the body surface: a short dorsal ciliary arch extending transversely at the basis of the frontal lobe and a wide C-shaped left ciliary arch in the left concavity. Because of the presence of three ciliary zones in the non-retractable buccal ciliature, the present genus might be a member of the family Blepharocorythidae, but the large left concavity and the C-shaped left ciliary arch are unique, such structures have never been described from other blepharocorythids. [source]

    Conservation Biology Framework for the Release of Wild-Born Orphaned Chimpanzees into the Conkouati Reserve, Congo

    Caroline E. G. Tutin
    Release of captive individuals is complex and controversial, however, particularly when risks are potentially high, as in the case of orphaned apes. We describe the decision-making process that led to the successive release of 20 wild-born orphan chimpanzees ( Pan troglodytes troglodytes) into the Conkouati Reserve in the Republic of Congo. Recommendations of the Reintroduction Specialist Group of the World Conservation Union's Species Survival Commission were followed closely. The conservation status, ecology, and behavior of wild chimpanzees; the biological, social, economic and political context of the release site; and the health and genetic status of the candidates for release were all taken into account in the planning and execution of the project. Rigorous post-release monitoring of behavior and health allowed documentation of the outcome. The project was of benefit to the chimpanzees that were released but also brought broad benefits to the site through effective protection from poaching and deforestation, and direct and indirect benefits to local people. The genetic and behavioral diversity of chimpanzees require a variety of conservation strategies to reduce threats and maintain as many viable wild populations as possible. Resumen: El retorno de animales confiscados a sus hábitats nativos es deseable cuando ocasiona una contribución positiva para la conservación de la especie. Sin embargo, la liberación de individuos cautivos es compleja y controversial, particularmente cuando los riesgos son potencialmente altos, como es el caso de los monos huérfanos. Describimos el proceso de toma de decisiones que condujo a la liberación de exitosa de 20 chimpancés silvestres huérfanos ( Pan troglodytes troglodytes) dentro de la Reserva Conkouati de la República de Congo. Las recomendaciones del Grupo de especialistas en reintroducción de la UICN-SSC fueron seguidas de cerca. El estatus de conservación, ecología y conducta de los chimpancés silvestres; el contexto biológico, social, económico y político del sitio de liberación y la salud y estatus genético de los candidatos a ser liberados fueron también tomados en consideración en la planeación y ejecución del proyecto. El monitoreo riguroso post-liberación de la conducta y salud permitió la documentación de los resultados. El proyecto fue benéfico para los chimpancés liberados pero también trajo beneficios amplios al sitio mediante la protección efectiva de la caza fortuita y la deforestación y beneficios directos e indirectos para la población humana local. La diversidad genética y conductual de los chimpancés requiere de una variedad de estrategias de conservación para reducir las amenazas y mantener cuantas poblaciones silvestres viables sean posibles. [source]

    Components of Relationship Quality in Chimpanzees

    ETHOLOGY, Issue 9 2008
    Orlaith N. Fraser
    A novel approach to studying social relationships in captive adult chimpanzees (Pan troglodytes) was taken by using principal components analysis (PCA) to extract three key components of relationship quality from nine behavioural variables. Based on the loadings of the behavioural variables, the components appeared to match previously hypothesized critical aspects of social relationships and were therefore labelled Value, Compatibility and Security. The effects of kinship, sex combination, age difference and time spent together on each of the relationship quality components were analysed. As expected, kin were found to have more valuable, compatible and secure relationships than non-kin. Female,female dyads were found to be more compatible than male,male or mixed-sex dyads, whereas the latter were found to be most secure. Partners of a similar age were found to have more secure and more valuable relationships than those with a larger age gap. Individuals that were together in the group for longer were more valuable and more compatible, but their relationships were found to be less secure than individuals that were together in the group for a shorter time. Although some of the results may be unexpected based on chimpanzee socio-ecology, they fit well overall with the history and social dynamics of the study group. The methods used confer a significant advantage in producing quantitative composite measures of each component of relationship quality, obtained in an objective manner. These findings therefore promote the use of such measures in future studies requiring an assessment of the qualities of dyadic social relationships. [source]

    Immediate and Delayed Benefits of Play Behaviour: New Evidence from Chimpanzees (Pan troglodytes)

    ETHOLOGY, Issue 12 2004
    E. Palagi
    Evidence for the anticipation of competition at feeding time has been previously documented in both Pan species. Chimpanzees seem to cope with competitive tendency through behavioural mechanisms of tension reduction, and grooming is certainly one of these. Social play and grooming are often matched because they bring animals into close physical contact for long periods, and they have an important role in social cohesion. Our goal was to investigate the occurrence of play behaviour during the pre-feeding period, before a basic maintenance activity is about to take place, in the chimpanzee colony housed in the ZooParc de Beauval (St Aignan sur Cher, France). The group was composed of 10 adults and nine immature individuals. By scan animal sampling (344 h of observation), we recorded play and grooming interactions in all age-class combinations during four different periods (pre-feeding, feeding, post-feeding, control). We found peak levels of grooming interactions among adults during the pre-feeding time. A peak frequency at the pre-feeding time was also found in social play between adults and unrelated immature subjects. This finding suggests that during high tension periods, grooming and play might share similar functions in conflict management. Like grooming, play might have an important role to limit aggression and increase tolerance around food (immediate benefits). Immature animals showed a higher frequency of play in the pre-feeding than in any other condition (feeding, post-feeding, and control). During high excitement periods social play probably represents a safe mechanism for immature subjects to test their personal abilities (self-assessment), the strength/weakness of playmates, and the degree of cooperation/competition with them (social-assessment). In the light of this new evidence, we can assert that play behaviour is far from being a purposeless activity, at least in the chimpanzee colony under study. [source]

    Leaf Processing by Wild Chimpanzees: Physically Defended Leaves Reveal Complex Manual Skills

    ETHOLOGY, Issue 8 2002
    Nadia Corp
    The manual processing of eight species of leaf was investigated in the M-group chimpanzees of Mahale Mountains National Park, Tanzania. Leaf species varied in the extent to which physical defences made consumption difficult. In all, 96 distinct techniques for leaf processing were identified, but two species with defended leaves (Ficus asperifolia and F. exasperata) required 2.5 as many techniques as did any of the six undefended species. Moreover, chimpanzees made more multiple leaf detachments, and made more subsequent modifications of the leaves, when dealing with the leaves of these two Ficus species, compared with the undefended leaf species. This greater complexity was associated with evidence of flexible, hierarchical organization of the process: iteration of modules consisting of several processing elements, facultative omission of modules, or substitutions of alternative modules. Comparison with data from mountain gorillas is made, and is consistent with similar cognitive architecture in the two species. We consider that, not only is hierarchical organization currently associated with mechanical difficulty in food processing, but that over evolutionary time-scales difficulties in food processing may have selected for cognitive advance. [source]

    Chimpanzee Forest exhibit at Chester Zoo

    In 2000 an exhibit was altered substantially for Chimpanzees Pan troglodytes at Chester Zoo. A flat grass-covered island was initially planted with over 300 plants of 31 species and a complex climbing structure, made from poles, hammocks, tyres and cargo nets, was erected in the centre of the enclosure. In this article the new Chimpanzee Forest exhibit is described and details of the plantings are given. The ways in which the structure and vegetation have improved the environment and how the Chimpanzees use the redesigned space are also reported. [source]

    Chimpanzees in hepatitis C virus research: 1998,2007

    R.H. Bettauer
    Abstract Background, Chimpanzees have been widely used in hepatitis C virus (HCV) research, but their endangered status and high financial and ethical costs have prompted a closer review. Methods, One hundred and nine articles published in 1998,2007 were analyzed for the number of chimpanzees involved, experimental procedures, objectives and other relevant issues. Results, The articles described the use of 852 chimpanzees, but accounting for likely multiple uses, the number of individual chimpanzees involved here is estimated to be approximately 500. Most articles addressed immunology and inoculation studies. A significant portion of studies lasted for several months or years. Approximately one half of the individual chimpanzees were each used in 2,10 studies. Conclusions, Significant financial and scientific resources have been expended in these chimpanzee HCV studies. Discussion addresses troublesome questions presented by some of the reviewed articles, including statistical validity, repeatability, and biological relevance of this model. These concerns merit attention as future approaches to HCV research and research priorities are considered. [source]

    Pinpointing a selective sweep to the chimpanzee MHC class I region by comparative genomics

    MOLECULAR ECOLOGY, Issue 8 2008
    Abstract Chimpanzees experienced a reduction of the allelic repertoire at the major histocompatibility complex (MHC) class I A and B loci, which may have been caused by a retrovirus belonging to the simian immunodeficiency virus (SIV) family. Extended MHC haplotypes were defined in a pedigreed chimpanzee colony. Comparison of genetic variation at microsatellite markers mapping inside and outside the Mhc region was carried out in humans and chimpanzees to investigate the genomic extent of the repertoire reduction. Multilocus demographic analyses underscored that chimpanzees indeed experienced a selective sweep that mainly targeted the chromosomal segment carrying the Mhc class I region. Probably due to genetic linkage, the sweep also affected other polymorphic loci, mapping in the close vicinity of the Mhc class I region genes. Nevertheless, although the allelic repertoire at particular Mhc class I and II loci appears to be limited, naturally occurring recombination events allowed the establishment of haplotype diversity after the sweep. However, recombination did not have sufficient time to erase the signal of the selective sweep. [source]

    Brief communication: Reaction to fire by savanna chimpanzees (Pan troglodytes verus) at Fongoli, Senegal: Conceptualization of "fire behavior" and the case for a chimpanzee model

    Jill D. Pruetz
    Abstract The use and control of fire are uniquely human traits thought to have come about fairly late in the evolution of our lineage, and they are hypothesized to correlate with an increase in intellectual complexity. Given the relatively sophisticated cognitive abilities yet small brain size of living apes compared to humans and even early hominins, observations of wild chimpanzees' reactions to naturally occurring fire can help inform hypotheses about the likely responses of early hominins to fire. We use data on the behavior of savanna chimpanzees (Pan troglodytes verus) at Fongoli, Senegal during two encounters with wildfires to illuminate the similarities between great apes and humans regarding their reaction to fire. Chimpanzees' close relatedness to our lineage makes them phylogenetically relevant to the study of hominid evolution, and the open, hot and dry environment at Fongoli, similar to the savanna mosaic thought to characterize much of hominid evolution, makes these apes ecologically important as a living primate model as well. Chimpanzees at Fongoli calmly monitor wildfires and change their behavior in anticipation of the fire's movement. The ability to conceptualize the "behavior" of fire may be a synapomorphic trait characterizing the human-chimpanzee clade. If the cognitive underpinnings of fire conceptualization are a primitive hominid trait, hypotheses concerning the origins of the control and use of fire may need revision. We argue that our findings exemplify the importance of using living chimpanzees as models for better understanding human evolution despite recently published suggestions to the contrary. Am J Phys Anthropol, 2010. © 2009 Wiley-Liss, Inc. [source]

    Understanding hind limb weight support in chimpanzees with implications for the evolution of primate locomotion

    David A. Raichlen
    Abstract Most quadrupedal mammals support a larger amount of body weight on their forelimbs compared with their hind limbs during locomotion, whereas most primates support more of their body weight on their hind limbs. Increased hind limb weight support is generally interpreted as an adaptation that reduces stress on primates' highly mobile forelimb joints. Thus, increased hind limb weight support was likely vital for the evolution of primate arboreality. Despite its evolutionary importance, the mechanism used by primates to achieve this important kinetic pattern remains unclear. Here, we examine weight support patterns in a sample of chimpanzees (Pan troglodytes) to test the hypothesis that limb position, combined with whole body center of mass position (COM), explains increased hind limb weight support in this taxon. Chimpanzees have a COM midway between their shoulders and hips and walk with a relatively protracted hind limb and a relatively vertical forelimb, averaged over a step. Thus, the limb kinematics of chimpanzees brings their feet closer to the COM than their hands, generating greater hind limb weight support. Comparative data suggest that these same factors likely explain weight support patterns for a broader sample of primates. It remains unclear whether primates use these limb kinematics to increase hind limb weight support, or whether they are byproducts of other gait characteristics. The latter hypothesis raises the intriguing possibility that primate weight support patterns actually evolved as byproducts of other traits, or spandrels, rather than as adaptations to increase forelimb mobility. Am J Phys Anthropol, 2009. © 2008 Wiley-Liss, Inc. [source]

    Chimpanzee responses to researchers in a disturbed forest,farm mosaic at Bulindi, western Uganda

    Matthew R. McLennan
    Abstract We describe the behavior of a previously unstudied community of wild chimpanzees during opportunistic encounters with researchers in an unprotected forest,farm mosaic at Bulindi, Uganda. Data were collected during 115 encounters between May 2006 and January 2008. Individual responses were recorded during the first minute of visual contact. The most common responses were "ignore" for arboreal chimpanzees and "monitor" for terrestrial individuals. Chimpanzees rarely responded with "flight". Adult males were seen disproportionately often relative to adult females, and accounted for 90% of individual responses recorded for terrestrial animals. Entire encounters were also categorized based on the predominant response of the chimpanzee party to researcher proximity. The most frequent encounter type was "ignore" (36%), followed by "monitor" (21%), "intimidation" (18%) and "stealthy retreat" (18%). "Intimidation" encounters occurred when chimpanzees were contacted in dense forest where visibility was low, provoking intense alarm and agitation. Adult males occasionally acted together to repel researchers through aggressive mobbing and pursuit. Chimpanzee behavior during encounters reflects the familiar yet frequently agonistic relationship between apes and local people at Bulindi. The chimpanzees are not hunted but experience high levels of harassment from villagers. Human-directed aggression by chimpanzees may represent a strategy to accommodate regular disruptions to foraging effort arising from competitive encounters with people both in and outside forest. Average encounter duration and proportion of encounters categorized as "ignore" increased over time, whereas "intimidation" encounters decreased, indicating some habituation occurred during the study. Ecotourism aimed at promoting tolerance of wildlife through local revenue generation is one possible strategy for conserving great apes on public or private land. However, the data imply that habituating chimpanzees for viewing-based ecotourism in heavily human-dominated landscapes, such as Bulindi, is ill-advised since a loss of fear of humans could lead to increased negative interactions with local people. Am. J. Primatol. Am. J. Primatol. 72:907,918, 2010. © 2010 Wiley-Liss, Inc. [source]

    Energetic costs of territorial boundary patrols by wild chimpanzees

    Sylvia J. Amsler
    Abstract Chimpanzees are well known for their territorial behavior. Males who belong to the same community routinely patrol their territories, occasionally making deep incursions into those of their neighbors. Male chimpanzees may obtain several fitness benefits by participating in territorial boundary patrols, but patrolling is also likely to involve fitness costs. Patrollers risk injury or even death, and patrols may be energetically costly and may involve opportunity costs. Although territorial patrols have been reported at all long-term chimpanzee study sites, quantitative data on their energetic costs have not previously been available. I evaluated the energy costs of patrolling for male chimpanzees at Ngogo, Kibale National Park, Uganda during 14 months of observation. In 29 patrols and matched control periods, I recorded the distances covered and time spent traveling and feeding by chimpanzees. I found that male chimpanzees covered longer distances, spent more time traveling, and spent less time feeding during patrols than during control periods. These results support the hypothesis that chimpanzees incur energetic costs while patrolling and suggest that ecological factors may constrain the ability of chimpanzees to patrol. Am. J. Primatol. 72:93,103, 2010. © 2009 Wiley-Liss, Inc. [source]

    Volumetric and lateralized differences in selected brain regions of chimpanzees (Pan troglodytes) and bonobos (Pan paniscus)

    William D. Hopkins
    Abstract The two species of Pan, bonobos and common chimpanzees, have been reported to have different social organization, cognitive and linguistic abilities and motor skill, despite their close biological relationship. Here, we examined whether bonobos and chimpanzee differ in selected brain regions that may map to these different social and cognitive abilities. Eight chimpanzees and eight bonobos matched on age, sex and rearing experiences were magnetic resonance images scanned and volumetric measures were obtained for the whole brain, cerebellum, striatum, motor-hand area, hippocampus, inferior frontal gyrus and planum temporale. Chimpanzees had significantly larger cerebellum and borderline significantly larger hippocampus and putamen, after adjusting for brain size, compared with bonobos. Bonobos showed greater leftward asymmetries in the striatum and motor-hand area compared with chimpanzees. No significant differences in either the volume or lateralization for the so-called language homologs were found between species. The results suggest that the two species of Pan are quite similar neurologically, though some volumetric and lateralized differences may reflect inherent differences in social organization, cognition and motor skills. Am. J. Primatol. 71:988,997, 2009. © 2009 Wiley-Liss, Inc. [source]

    Chimpanzee seed dispersal quantity in a tropical montane forest of Rwanda

    Nicole D. Gross-Camp
    Abstract We describe chimpanzee seed dispersal in the tropical montane forest of Nyungwe National Park (NNP), Rwanda, for a total of three years from January 1998 through May 2000 and May 2006 through March 2007. Relatively few studies have examined chimpanzee seed dispersal in montane communities where there are generally fewer fruiting tree species than in lowland forests. Such studies may reveal new insights into chimpanzee seed dispersal behaviors and the role that they play in forest regeneration processes. Chimpanzees are large-bodied, highly frugivorous, and tend to deposit the seeds of both large- and small-seeded fruits they consume in a viable state. We found that chimpanzees dispersed a total of 37 fruiting species (20 families) in their feces, 35% of which were large-seeded trees (,0.5,cm). A single large-seeded tree, Syzygium guineense, was the only species to be dispersed in both wadges and feces. Based on phenological patterns of the top five large-seeded tree species found in chimpanzee feces, our results indicate that chimpanzees do not choose fruits based on their availability. There was, however, a positive relationship between the presence of Ekebergia capensis seeds in chimpanzee feces and S. guineense seeds in chimpanzee wadges and their respective fruit availabilities. Our data reveal that proportionately fewer chimpanzee fecal samples at NNP contained seeds than that reported in two other communities in the Albertine Rift including one at mid-elevation and one in montane forest. As in other chimpanzee communities, seeds of Ficus spp. were the most common genus in NNP chimpanzee feces. Our data do not support previous studies that describe Ficus spp. as a fallback food for chimpanzees and highlights an intriguing relationship between chimpanzees and the large-seeded tree species, S. guineense. Am. J. Primatol. 71:901,911, 2009. © 2009 Wiley-Liss, Inc. [source]

    Use of wild and cultivated foods by chimpanzees at Bossou, Republic of Guinea: feeding dynamics in a human-influenced environment

    Kimberley J. Hockings
    Abstract Increased human population growth and more conversions of natural habitat to agricultural land have resulted in greater proximity between humans and nonhuman primate species. Consequent increases in resource competition including crop-raiding are a by-product of both natural resources becoming less available and the nutritional benefits of cultivated foods becoming more known to the nonhuman primates. Chimpanzees at Bossou in the Republic of Guinea, West Africa, consume 17 different types of cultivated foods that are grown extensively throughout their small, fragmented home range. Direct observations of feeding behavior conducted over an 18-month period revealed that during specific months crops account for up to one quarter of chimpanzee feeding time, with higher overall crop-raiding levels throughout the periods of wild fruit scarcity. Some cultivated foods, especially sugar fruits, are mostly fallback foods, whereas others, such as rice pith (Oryza sp.) and maize (Zea mays), are consumed according to their availability even when wild foods are abundant. These findings highlight the importance of both crop choice by farmers and a thorough understanding of the ecology of resident primate species when establishing land management techniques for alleviating human,primate conflict. Am. J. Primatol. 71:636,646, 2009. © 2009 Wiley-Liss, Inc. [source]

    Interactions between zoo-housed great apes and local wildlife

    S.R. Ross
    Abstract Although there are published reports of wild chimpanzees, bonobos, and orangutans hunting and consuming vertebrate prey, data pertaining to captive apes remain sparse. In this survey-based study, we evaluate the prevalence and nature of interactions between captive great apes and various indigenous wildlife species that range into their enclosures in North America. Our hypotheses were threefold: (a) facilities housing chimpanzees will report the most frequent and most aggressive interactions with local wildlife; (b) facilities housing orangutans and bonobos will report intermediate frequencies of these interactions with low levels of aggression and killing; and (c) facilities housing gorillas will report the lowest frequency of interactions and no reports of killing local wildlife. Chimpanzees and bonobos demonstrated the most aggressive behavior toward wildlife, which matched our predictions for chimpanzees, but not bonobos. This fits well with expectations for chimpanzees based on their natural history of hunting and consuming prey in wild settings, and also supports new field data on bonobos. Captive gorillas and orangutans were reported to be much less likely to chase, catch and kill wildlife than chimpanzees and bonobos. Gorillas were the least likely to engage in aggressive interactions with local wildlife, matching our predictions based on natural history. However unlike wild gorillas, captive gorillas were reported to kill (and in one case, eat) local wildlife. These results suggest that some behavioral patterns seen in captive groups of apes may be useful for modeling corresponding activities in the wild that may not be as easily observed and quantified. Furthermore, the data highlight the potential for disease transmission in some captive settings, and we outline the associated implications for ape health and safety. Am. J. Primatol. 71:458,465, 2009. © 2009 Wiley-Liss, Inc. [source]

    Reproductive aging in captive and wild common chimpanzees: factors influencing the rate of follicular depletion

    Sylvia Atsalis
    Abstract We examine and discuss evidence of contrasting differences in fertility patterns between captive and wild female chimpanzees, Pan troglodytes, as they age; in the wild females reproduce in their 40s, but captive studies suggest that menopause occurs around that time. Thus, despite the increased longevity generally observed in captive populations reproductive life span is shortened. We outline a hypothesis to explain the apparent differential pace of reproductive decline observed between wild and captive populations. The breeding schedules of captive primates may contribute to accelerated reproductive senescence because continuous cycling in captive animals results in early depletion of the ovarian stock and premature senescence. Available evidence supports the hypothesis that women with patterns of high oocyte loss experience earlier menopause. Chimpanzees in captivity live longer, and thus, similar to humans, they may experience follicular depletion that precedes death by many years. In captivity, chimpanzees typically have an early age at menarche and first birth, shorter interbirth intervals associated with short lactational periods as young mature faster, and nursery rearing, which allows mothers to begin cycling earlier. Variables typical of wild chimpanzee populations, including late age at menarche and first birth, long interbirth intervals associated with prolonged lactational periods, and a long period of female infertility after immigration, spare ovulations and may be responsible for the later age at reproductive termination. Finally, we describe and discuss the timing of specific reproductive landmarks that occur as female chimpanzees age, distinguishing between functional menopause (age at last birth) and operational menopause (end of cycling). Am. J. Primatol. 71:271,282, 2009. © 2008 Wiley-Liss, Inc. [source]

    A map of the common chimpanzee genome

    BIOESSAYS, Issue 6 2002
    Derek E. Wildman
    The completion of the chimpanzee genome will greatly help us determine which genetic changes are unique to humanity. Chimpanzees are our closest living relative, and a recent study has made considerable progress towards decoding the genome of our sister taxon.1 Over 75,000 common chimpanzee (Pan troglodytes) bacterial artificial chromosome end sequences were aligned and mapped to the human genome. This study shows the remarkable genetic similarity (98.77%) between humans and chimpanzees, while highlighting intriguing areas of potential difference. If we wish to understand the genetic basis of humankind, the completion of the chimpanzee genome deserves high priority. BioEssays 24:490,493, 2002. © 2002 Wiley Periodicals, Inc. [source]

    The Contribution of Long-Term Research at Gombe National Park to Chimpanzee Conservation

    chimpancé; conservación de simios mayores; Parque Nacional Gombe; Tanzania Abstract:,Long-term research projects can provide important conservation benefits, not only through research specifically focused on conservation problems, but also from various incidental benefits, such as increased intensity of monitoring and building support for the protection of an area. At Gombe National Park, Tanzania, long-term research has provided at least four distinct benefits to wildlife conservation. (1) Jane Goodall's groundbreaking discoveries of chimpanzee (Pan troglodytes) tool use, hunting, and complex social relationships in what was then a game reserve drew attention to the area and created support for upgrading Gombe to national park status in 1968. (2) The highly publicized findings have earned Gombe and Tanzania the attention of a worldwide public that includes tourists and donors that provide financial support for Gombe, other parks in Tanzania, and chimpanzee conservation in general. (3) Crucial information on social structure and habitat use has been gathered that is essential for effective conservation of chimpanzees at Gombe and elsewhere. (4) A clear picture of Gombe's chimpanzee population over the past 40 years has been determined, and this has helped identify the greatest threats to the viability of this population, namely disease and habita loss outside the park. These threats are severe and because of the small size of the population it is extremely vulnerable. Research at Gombe has led to the establishment of conservation education and development projects around Gombe, which are needed to build local support for the park and its chimpanzees, but saving these famous chimpanzees will take a larger integrated effort on the part of park managers, researchers, and the local community with financial help from international donors. Resumen:,Los proyectos de investigación de largo plazo pueden proporcionar beneficios importantes a la conservación, no solo a través de investigación enfocada específicamente a problemas de conservación, sino también a través de varios beneficios incidentales, como una mayor intensidad de monitoreo y construcción de soporte para la protección de un área. En el Parque Nacional Gombe, Tanzania, la investigación a largo plazo ha proporcionado por lo menos cuatro beneficios a la conservación de vida silvestre. (1) Los descubrimientos innovadores de Jane Goodall sobre el uso de herramientas, la cacería y las complejas relaciones sociales de chimpancés en lo que entonces era una reserva de caza atrajeron la atención al área y crearon el soporte para cambiar a Gombe a estatus de parque nacional en 1968. (2) Los hallazgos muy publicitados han ganado para Gombe y Tanzania la atención del público en todo el mundo incluyendo turistas y donadores que proporcionan soporte financiero a Gombe, otros parques en Tanzania y a la conservación de chimpancés en general. (3) Se ha reunido información crucial sobre la estructura social y el uso del hábitat que ha sido esencial para la conservación efectiva de chimpancés en Gombe y otros sitios. (4) Se ha determinado un panorama claro de la población de chimpancés en Gombe durante los últimos 40 años, y esto a ayudado a identificar las mayores amenazas a la viabilidad de esta población, a saber enfermedades y pérdida de hábitat fuera del parque. Estas amenazas son severas y la población es extremadamente vulnerable por su tamaño pequeño. La investigación en Gombe ha llevado al establecimiento de proyectos de desarrollo y de educación para la conservación en los alrededores del parque, lo cual es necesario para encontrar soporte local para el parque y sus chimpancés, pero el rescate de estos famosos chimpancés requerirá de un esfuerzo más integrado de parte de los manejadores del parque, investigadores y la comunidad local con la ayuda financiera de donadores internacionales. [source]

    Long peptides induce polyfunctional T cells against conserved regions of HIV-1 with superior breadth to single-gene vaccines in macaques

    Maximillian Rosario
    Abstract A novel T-cell vaccine strategy designed to deal with the enormity of HIV-1 variation is described and tested for the first time in macaques to inform and complement approaching clinical trials. T-cell immunogen HIVconsv, which directs vaccine-induced responses to the most conserved regions of the HIV-1, proteome and thus both targets diverse clades in the population and reduces the chance of escape in infected individuals, was delivered using six different vaccine modalities: plasmid DNA (D), attenuated human (A) and chimpanzee (C) adenoviruses, modified vaccinia virus Ankara (M), synthetic long peptides, and Semliki Forest virus replicons. We confirmed that the initial DDDAM regimen, which mimics one of the clinical schedules (DDDCM), is highly immunogenic in macaques. Furthermore, adjuvanted synthetic long peptides divided into sub-pools and delivered into anatomically separate sites induced T-cell responses that were markedly broader than those elicited by traditional single-open-reading-frame genetic vaccines and increased by 30% the overall response magnitude compared with DDDAM. Thus, by improving both the HIV-1-derived immunogen and vector regimen/delivery, this approach could induce stronger, broader, and theoretically more protective T-cell responses than vaccines previously used in humans. [source]

    Is culture a golden barrier between human and chimpanzee?

    Christophe Boesch
    Abstract Culture pervades much of human existence. Its significance to human social interaction and cognitive development has convinced some researchers that the phenomenon and its underlying mechanisms represent a defining criterion for humankind. However, care should be taken not to make hasty conclusions in light of the growing number of observations on the cultural abilities of different species, ranging from chimpanzees and orangutans to whales and dolphins. The present review concentrates on wild chimpanzees and shows that they all possess an extensive cultural repertoire. In the light of what we know from humans, I evaluate the importance of social learning leading to acquisition of cultural traits, as well as of collective meaning of communicative traits. Taking into account cross-cultural variations in humans, I argue that the cultural abilities we observe in wild chimpanzees present a broad level of similarity between the two species. [source]

    A study on genomic distribution and sequence features of human long inverted repeats reveals species-specific intronic inverted repeats

    FEBS JOURNAL, Issue 7 2009
    Yong Wang
    The inverted repeats present in a genome play dual roles. They can induce genomic instability and, on the other hand, regulate gene expression. In the present study, we report the distribution and sequence features of recombinogenic long inverted repeats (LIRs) that are capable of forming stable stem-loops or palindromes within the human genome. A total of 2551 LIRs were identified, and 37% of them were located in long introns (largely > 10 kb) of genes. Their distribution appears to be random in introns and is not restrictive, even for regions near intron,exon boundaries. Almost half of them comprise TG/CA-rich repeats, inversely arranged Alu repeats and MADE1 mariners. The remaining LIRs are mostly unique in their sequence features. Comparative studies of human, chimpanzee, rhesus monkey and mouse orthologous genes reveal that human genes have more recombinogenic LIRs than other orthologs, and over 80% are human-specific. The human genes associated with the human-specific LIRs are involved in the pathways of cell communication, development and the nervous system, as based on significantly over-represented Gene Ontology terms. The functional pathways related to the development and functions of the nervous system are not enriched in chimpanzee and mouse orthologs. The findings of the present study provide insight into the role of intronic LIRs in gene regulation and primate speciation. [source]

    Deconstructing language by comparative gene expression: from neurobiology to microarray

    M. C. Oldham
    Language is a defining characteristic of our species that has emerged quite recently on an evolutionary timescale. Understanding the neurobiological substrates and genetic underpinnings of language constitutes a basic challenge for both neuroscience and genetics. The functional localization of language in the brain has been progressively refined over the last century through studies of aphasics and more recently through neuroimaging. Concurrently, structural specializations in these brain regions have been identified by virtue of their lateralization in humans and also through comparisons with homologous brain regions in non-human primate species. Comparative genomics has revealed the genome of our closest living relative, the chimpanzee, to be astonishingly similar to our own. To explore the role that changes in the regulation of gene expression have had in recent human evolution, several groups have used microarrays to compare expression levels for thousands of genes in the brain between humans and chimpanzees. By applying this approach to the increasingly refined peri-sylvian network of brain regions involved in language, it may be possible to discern functionally significant changes in gene expression that are universal among humans but unique to our species, thus casting light on the molecular basis of language in the brain. [source]

    Farsightedness (presbyopia) in a wild elderly chimpanzee: The first report

    Michiko Fujisawa
    No abstract is available for this article. [source]

    Distinguishing between the nests of sympatric chimpanzees and gorillas

    Summary 1Our current inability to estimate precisely the population sizes of chimpanzees and gorillas across much of the Congo Basin has been detrimental to the development of conservation strategies for the preservation of these endangered apes. Systematic counts of nests are currently the most commonly used method to estimate ape abundance, but distinguishing between the nests of sympatric chimpanzees and gorillas has proven to be an enduring obstacle to estimating species-specific abundance. In general, the builder of more than 75% of nests recorded during surveys is undetermined. We hypothesized that sleeping habits and nest building patterns would allow us to differentiate between the nests of these apes. 2We constructed a predictive model using stepwise discriminant function analysis to determine characteristics that accurately distinguished between chimpanzee and gorilla nests. We analysed 13 variables associated with 3425 ape nests from three independent surveys conducted in the Goualougo Triangle of the Nouabalé-Ndoki National Park, Republic of Congo. 3The model correctly classified more than 90% of nests in our validation subsample. Nest height, nest type, forest type and understorey closure were identified as important variables for distinguishing between chimpanzee and gorilla nests at this site. Attributing nests to either species increased the precision of resulting density estimates, which enhanced the statistical power to detect trends in population fluctuation. 4Although specific variables may differ between study sites, we have demonstrated that predictive models to distinguish between the nests of sympatric chimpanzee and gorillas provide a promising approach to improving the quality of ape survey data. 5Synthesis and applications. Our study introduces an innovative solution to the dilemma of discriminating between the nests of sympatric chimpanzees and gorillas, which increases the specificity and precision of resulting ape abundance estimates. There is an urgent need to improve methods to evaluate and monitor remaining ape populations across western and central Africa that are experiencing the imminent threats of emergent diseases, poaching and expanding human development. Increasing the quality of density estimates from field survey data will aid in the development of local conservation initiatives, national strategies and international policies on behalf of remaining ape populations. [source]

    A survey of the apes in the Dzanga-Ndoki National Park, Central African Republic: a comparison between the census and survey methods of estimating the gorilla (Gorilla gorilla gorilla) and chimpanzee (Pan troglodytes) nest group density

    A. Blom
    Abstract A survey of apes was carried out between October 1996 and May 1997 in the Dzanga sector of the Dzanga-Ndoki National Park, Central African Republic (CAR), to estimate gorilla (Gorilla gorilla gorilla) and chimpanzee (Pan troglodytes) densities. The density estimates were based on nest counts. The strip transect census and the line transect survey method (Standing Crop Nest Count) were used to estimate the gorilla nest group density. The strip transect has been most commonly used to date. It assumes that all nest groups within the width of the strip are detected, but as this assumption is easily violated in the dense tropical rain forest, the line transect survey was also used. In this method, only the nest groups on the transect line itself should be detected. This method proved to be an adequate and easy technique for estimating animal densities in dense vegetation. The gorilla density of 1.6 individuals km,2 (line transect survey method) found for the Dzanga sector is one of the highest densities ever reported in the literature for the Western lowland gorilla. The density estimate for chimpanzees was 0.16 individuals km,2 (census method). The results of this study confirm the importance of the Dzanga-Ndoki National Park for primate conservation. Résumé Entre octobre 1996 et mai 1997, on a étudié les grands singes du secteur de Dzanga dans le Parc National de Dzanga-Ndoki, en République Centrafricaine (RCA), pour évaluer les densités de gorilles (Gorilla gorilla gorilla) et de chimpanzés (Pan troglodytes). Les estimations de densité se basaient sur le comptage des nids. On a utilisé le recensement par bande transect et la méthode de contrôle par transect linéaire (comptage réel des nids) pour estimer la densité des groupes de nids de gorilles. C'est la bande transect qui est la plus communément utilisée à ce jour. Cela suppose que l'on détecte tous les groupes de nids inclus dans la largeur de la bande, mais comme cette supposition est facilement mise en défaut dans la forêt tropicale humide dense, on a aussi utilisé la méthode des transects en ligne. Avec cette méthode, seuls les groupes de nids qui sont sur la ligne de transect doivent être détectés. Cette méthode s'est révélée une technique adéquate et facile pour estimer les densités animales dans la végétation dense. La densité des gorilles (1,6 individus / km2) relevée pour le secteur de Dzanga est une des plus élevées jamais reportées dans la littérature pour le Gorille de plaine occidental. On a estimé la densité des chimpanzés à 0,16 individus / km2 (par la méthode de recensement). Les résultats de cette étude confirment l'importance du Parc National de Dzanga-Ndoki pour la conservation des primates. [source]

    Analyses of amino acid sequences in hypervariable region-1 of hepatitis C virus (HCV) in sera from chimpanzees infected three times with the same HCV strain

    M. Sugitani
    Abstract Background, To investigate whether or not the same strain of hepatitis C virus (HCV) can twice re-infect the same chimpanzee, we analyzed nucleic and amino acid sequences in HCV hypervariable region-1 (HVR1). Two chimpanzees were inoculated, three times each, with the same HCV strain during the 1983,1991. After each inoculation, chimpanzees developed acute hepatitis C, and then recovered. Methods, Using sera, HVR1 cloning and antibody to HVR1 major clone measurement were performed. Results, Clones from the first inoculum were divisible into major and minor types. Clones from the second and third inocula, as well as all post-inoculation sera, were essentially identical to the major type. Titers of antibody to HVR1 major clone were consistently low in pre- and post-inoculation sera. Conclusions, Both chimpanzees were re-infected twice with the same strain of HCV. The sequences from the second and third infections were similar to the major sequences in the first inoculum. [source]

    Lessons from naked apes and their infections

    Robin A. Weiss
    Abstract Human infections come from two main sources. Our ,family heirlooms' have co-evolved with the host as we diverged from the common ancestor of humans and chimpanzees, and these are often vertically transmitted. Our ,new acquisitions' come from cross-species infections, and these are typically horizontally transmitted. Compared with other apes, naked apes harbor a larger variety of pathogens, acquired from the domesticated and commensal non-primate species which share our habitat, as well as from exotic species. Thus we are nouveaux riches in our collection of infections or ,metagenome' and this is reviewed with particular reference to retroviruses. Nakedness poses a challenge to ectoparasites which is discussed in relation to the origin and evolution of human lice from those of the great apes. As humans have acquired infections horizontally from our closest living relatives, the chimpanzee and the gorilla, might we also have exchanged pathogens with other hominid species? [source]

    Urinary steroids, FSH and CG measurements for monitoring the ovarian cycle and pregnancy in the chimpanzee

    Keiko Shimizu
    Abstract: Non-invasive methods for monitoring reproductive status of chimpanzee based on the measurement of urinary steroids and gonadotropins were examined. A typical pre-ovulatory urinary estrone conjugate (E1C) surge and post-ovulatory increase in pregnandiol glucuronide (PdG) were seen during the menstrual cycle. Urinary follicle stimulating hormone (FSH) showed two peaks over the infertile menstrual cycle. The earliest changes indicating pregnancy were a coincident rise in E1C and chorionic gonadotropin (CG) levels and a concomitant fall in FSH levels. Urinary PdG levels showed a prolonged rise. Urinary E1C in the pregnant chimpanzee was higher than during the menstrual cycle and increased with advancing gestation, with maximum levels occurring near term. In the case of stillbirth, E1C and CG levels from mid- through late-pregnancy were low and the prepartum progressive increase in E1C was not shown. The data presented here are of great practical value in captive breeding management of chimpanzees. [source]