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comparison between the complete mitochondrial dna sequences of homo and the common chimpanzee based on nonchimeric sequences.the complete mitochondrial dna (mtdna) molecules of homo and of the common chimpanzee were sequenced. each sequence was established from tissue of one individual and thus nonchimeric. both sequences were assembled in their entirety from natural (not pcr amplified) clones. comparison with sequences in the literature identified the chimpanzee specimen as pan troglodytes verus, the west african variety of the species. the nucleotide difference between the complete human and chimpanzee sequences is ...19968919866
high variety of different simian t-cell leukemia virus type 1 strains in chimpanzees (pan troglodytes verus) of the taï national park, côte d'ivoire.we found human t-cell leukemia virus type 1- and simian t-cell leukemia virus type 1 (stlv-1)-related infections in 5 of 10 chimpanzees originating from three groups of wild chimpanzees. the new virus isolates showed a surprising heterogeneity not only in comparison to stlv-1 described previously in other primate species but also between the different chimpanzee groups, within a group, or even between strains isolated from an individual animal. the interdisciplinary combination of virology, mole ...200415047848
subspecies composition and founder contribution of the captive u.s. chimpanzee (pan troglodytes) population.chimpanzees are presently classified into three subspecies: pan troglodytes verus from west africa, p.t. troglodytes from central africa, and p.t. schweinfurthii from east africa. a fourth subspecies (p.t. vellerosus), from cameroon and northern nigeria, has been proposed. these taxonomic designations are based on geographical origins and are reflected in sequence variation in the first hypervariable region (hvr-i) of the mtdna d-loop. although advances have been made in our understanding of chi ...200516229023
a link between sivsm in sooty mangabeys (sm) in wild-living monkeys in sierra leone and sivsm in an american-based sm colony.we have developed a noninvasive method for sivsm virion rna detection in feces of captive sooty mangabeys (sms) (cercocebus atys). employing this method to investigate the natural history of sivsm in endangered sms is useful for understanding the diversity and evolution of sivsm and hiv-2. the fecal samples of 61 wild-living sms and 14 chimpanzees (pan troglodytes verus) were studied. samples were collected in rural sierra leone in 1993. one sm sample tested positive by reverse transcriptase-pcr ...200415650427
mitochondrial dna genealogy of chimpanzees in the nimba mountains and bossou, west africa.the chimpanzee populations of the bossou and nimba regions in west africa were genetically surveyed to 1) reveal the genetic relationship between the bossou and nimba populations, and 2) elucidate the evolutionary relationship between the bossou-nimba and other west african populations. the chimpanzee group at bossou is characterized by its small population size, no evidence of contact with neighboring populations, and no female immigration. it is believed that most females and adolescent males ...200415538765
absence of the tap2 human recombination hotspot in chimpanzees.recent experiments using sperm typing have demonstrated that, in several regions of the human genome, recombination does not occur uniformly but instead is concentrated in "hotspots" of 1-2 kb. moreover, the crossover asymmetry observed in a subset of these has led to the suggestion that hotspots may be short-lived on an evolutionary time scale. to test this possibility, we focused on a region known to contain a recombination hotspot in humans, tap2, and asked whether chimpanzees, the closest li ...200415208713
characterization of a new simian t-lymphocyte virus type 1 (stlv-1) in a wild living chimpanzee (pan troglodytes verus) from ivory coast: evidence of a new stlv-1 group?a new strain of simian t-lymphotropic virus type 1 in blood samples from a chimpanzee that lived in the tropical rainforest of ivory coast is described. the sequence obtained from the long terminal repeat region of the genome is significantly divergent from all known human and nonhuman primate t-lymphotropic virus type 1 strains (963% homology to the closest related strains from central african subtype b) and clusters with none of the established clades. the tax sequences reveal two sequence dif ...200312698951
prevalence and genetic diversity of simian immunodeficiency virus infection in wild-living red colobus monkeys (piliocolobus badius badius) from the taï forest, côte d'ivoire sivwrc in wild-living western red colobus monkeys.numerous african primates are infected with simian immunodeficiency viruses (sivs). it is now well established that the clade of sivs infecting west-central african chimpanzees (pan troglodytes troglodytes) and western gorillas (gorilla gorilla gorilla) represent the progenitors of human immunodeficiency virus type 1 (hiv-1), whereas hiv-2 results from different cross-species transmissions of sivsmm from sooty mangabeys (cercocebus atys atys). we present here the first molecular epidemiological ...200817916449
reduced transmission and prevalence of simian t-cell lymphotropic virus in a closed breeding colony of chimpanzees (pan troglodytes verus).a retrospective study spanning 20 years was undertaken to investigate the prevalence and modes of transmission of a simian t-cell lymphotropic virus (stlv) in a closed breeding colony of chimpanzees. of the 197 animals tested, 22 had antibodies that were cross-reactive with human t-cell lymphotropic virus type-1 (htlv-i) antigens. the specificity of the antibody response was confirmed by western blot analysis and the presence of a persistent virus infection was established by pcr analysis of dna ...200312604813
ant-dipping among the chimpanzees of bossou, guinea, and some comparisons with other sites.we present a detailed study of ant-dipping among the wild chimpanzees (pan troglodytes verus) of bossou, in southeastern guinea, west africa. observations suggest a strong influence of prey (dorylusspp.) characteristics, including aggressiveness and/or gregariousness, on tool length and technique employed by the chimpanzees. bossou chimpanzees exhibit two ant-dipping techniques: 1) direct mouthing, and 2) pull-through. in addition, they were observed dipping for several species of dorylus ants, ...200212454957
survey of savanna chimpanzees (pan troglodytes verus) in southeastern sénégal.a survey of the western subspecies of chimpanzee (pan troglodytes verus) was conducted from 1 february to 9 april 2000 in sénégal, west africa, by the miami assirik pan project (mapp). in addition to the assirik area of the parc national du niokolo koba (pnnk), areas south and east of the park were surveyed. nests made by chimpanzees were used to estimate chimpanzee distribution and densities. within the pnnk, chimpanzees were estimated to occur at an average of 0.13 individuals/km(2). chimpanze ...200212325117
lack of evidence for hiv type 1-related sivcpz infection in captive and wild chimpanzees (pan troglodytes verus) in west africa.serum from 387 chimpanzees (pan troglodytes verus), caught in the wild or bred in captivity, was tested for antibody to hiv-1 and hiv-2, using second- and third-generation enzyme immunoassays. six samples were repeatedly positive; however, only one of these was western blot positive. serial sera drawn before and after the western blot-positive samples were seronegative, and thus we conclude that this sample represented specimen contamination, or mislabeling. thus, none of the 387 pan troglodytes ...200212079561
novel hepatitis b virus strain from a chimpanzee of central africa (pan troglodytes troglodytes) with an unusual antigenicity of the core protein.we and others have previously reported a hepatitis b virus (hbv)-like hepadnavirus strain which seemed to be indigenous to west african chimpanzees (pan troglodytes verus). after that, we obtained an hbsag-positive serum sample from a chimpanzee from central africa, named bassi, belonging to another subspecies (p. troglodytes troglodytes). the full-genome nucleotide sequence of the hepadnavirus from bassi showed a significant difference (9-26%) from those so far reported from primates including ...200111684895
paired chimpanzee hepatitis b virus (chhbv) and mtdna sequences suggest different chhbv genetic variants are found in geographically distinct chimpanzee subspecies.the surface antigen gene region from five chronic hepatitis b virus (hbv) infected chimpanzees was amplified by pcr and the sequence determined. sequence comparison confirmed that all of the sequences were chimpanzee hepatitis b virus (chhbv) and they appeared to represent three distinct clusters or branches. to address the question of whether the three branches represented recently identified subspecies of chimpanzees, we determined the sequence of the mitochondrial dna hypervariable d loop fro ...200111551650
behavioural diversity among the wild chimpanzee populations of bossou and neighbouring areas, guinea and côte d'ivoire, west africa. a preliminary report.we present a preliminary report on the differences and similarities in material culture among four neighbouring chimpanzee (pan troglodytes verus) communities. one of these communities includes bossou, a long-term field site of wild chimpanzees, in guinea, west africa. we also conducted surveys of three new sites. two of those surveyed areas, seringbara in guinea and yealé in côte d'ivoire, are located less than 12 km away from bossou in the nimba mountains region, which forms a natural boundary ...200111490130
capturing and toying with hyraxes (dendrohyrax dorsalis) by wild chimpanzees (pan troglodytes) at bossou, guinea.chimpanzees (pan troglodytes verus) were observed capturing and toying with western tree hyraxes (dendrohyrax dorsalis, order hyracoidea) at bossou, guinea. an adolescent female carried one hyrax for 15 hr, slept with it in her nest, and groomed it. the captive was not consumed. nearby adults ignored the hyrax. in another case, two adolescent males timidly inspected a small hyrax. these observations indicate that the chimpanzees at bossou do not regard the hyrax as a prey animal, supporting the ...200111170171
detection of hepatitis b virus infection in wild-born chimpanzees (pan troglodytes verus): phylogenetic relationships with human and other primate genotypes.infection with hepatitis b virus (hbv) was detected by serological testing for hbv surface antigen and by pcr assay for hbv dna in serum samples from two common chimpanzees (pan troglodytes subsp. verus) born in west africa. the complete genome sequences obtained by nucleotide sequencing of overlapping dna fragments amplified by pcr were compared with hbv variants recovered from other primates and with human genotypes a to f. both chimpanzee sequences were 3, 182 nucleotides in length, and the s ...200010756039
tt viruses (ttv) of non-human primates and their relationship to the human ttv genotypes.sera from eight different non-human primate species, in total 216 samples, were analysed for the presence of tt virus (ttv) sequences. a very high incidence of ttv infection was found in sera from both common chimpanzees and pygmy chimpanzees, 48.8% and 66.7%, respectively. sequence analysis of pcr fragments from two pygmy chimpanzees and seven common chimpanzees resulted in a total of 14 different ttv sequences. phylogenetic analysis, including human ttv of all known genotypes, revealed that: ( ...199910501506
dietary responses to fruit scarcity of wild chimpanzees at bossou, guinea: possible implications for ecological importance of tool use.a 13-month ecological study was conducted at bossou, guinea, west africa, to elucidate how a community of wild chimpanzees (pan troglodytes verus) deals with the scarcity of main foods. during the study period, fruit availability fluctuated radically. the chimpanzees were confirmed to depend heavily on three "keystone resources" which were available when their main foods (fruit pulp) were scarce. these were fruits of musanga cecropioides, oil-palm (elaeis guineensis) nuts, and oil-palm pith. the ...19989696145
use of leaves as cushions to sit on wet ground by wild chimpanzees.a new type of tool use, leaf cushion, by wild chimpanzees (pan troglodytes verus) at bossou, guinea, was found. we report two cases: one is indirect evidence; the other is direct observation of a chimpanzee who used the tool. both cases indicate that chimpanzees used a set of leaves as a cushion while sitting on wet ground. chimpanzees at bossou show various kinds of tool use, some of which are unique to the community. most of these behavioral patterns are substance tool use for obtaining food, ...19989519241
flexible feeding on cultivated underground storage organs by rainforest-dwelling chimpanzees at bossou, west africa.it has been proposed that exploitation of underground storage organs (usos) played an important role in the evolution of the genus homo, these items serving as 'fallback foods' during periods of low food availability. the use of usos as food by wild chimpanzees is infrequent and seen mostly in populations inhabiting relatively arid environments, such as the savanna. here, we specifically test the hypothesis that chimpanzees (pan troglodytes verus) inhabiting tropical wet forest at bossou (republ ...201020080283
diversity of stlv-1 strains in wild chimpanzees (pan troglodytes verus) from côte d'ivoire.simian t-lymphotropic viruses type 1 (stlv-1) are regarded as a highly conserved group of viruses with genotypes clustering according to geographic regions rather than to infected species. in free living west african chimpanzees we have described a variety of stlv-1 strains and suggested that this diversity results from interspecies transmissions. here we present new data on stlv-1 infections in these chimpanzees with the presence of two new distinct clades, proposing the establishing of two new ...201020214935
patterns of gastro-intestinal parasites and commensals as an index of population and ecosystem health: the case of sympatric western chimpanzees (pan troglodytes verus) and guinea baboons (papio hamadryas papio) at fongoli, senegal.the exponential decline of great apes over the past 50 years has resulted in an urgent need for data to inform population viability assessment and conservation strategies. health monitoring of remaining ape populations is an important component of this process. in support of this effort, we examined endoparasitic and commensal prevalence and richness as proxies of population health for western chimpanzees (pan troglodytes verus) and sympatric guinea baboons (papio hamadryas papio) at fongoli, se ...201120853397
no evidence for transmission of sivwrc from western red colobus monkeys (piliocolobus badius badius) to wild west african chimpanzees (pan troglodytes verus) despite high exposure through hunting.simian immunodeficiency viruses (sivs) are the precursors of human immunodeficiency viruses (hivs) which have led to the worldwide hiv/aids pandemic. by studying sivs in wild primates we can better understand the circulation of these viruses in their natural hosts and habitat, and perhaps identify factors that influence susceptibility and transmission within and between various host species. we investigated the siv status of wild west african chimpanzees (pan troglodytes verus) which frequently ...201121284842
"stepping-sticks" and "seat-sticks": new types of tools used by wild chimpanzees (pan troglodytes) in sierra leone.in tenkere, sierra leone, a community of wild chimpanzees (pan troglodytes verus) spent long hours eating the fruits and flowers of the kapok (ceiba pentandra) tree. the branches of this species are covered in sharp thorns which make movement in their high canopies problematic for the chimpanzees. in an apparent attempt to increase their mobility and to ease the discomfort of lengthy bouts of eating in these trees, some of the tenkere chimpanzees have been observed using stick tools as foot ("st ...19979064197
antimicrobial potential of 27 plants consumed by chimpanzees (pan troglodytes verus blumenbach) in ivory coast.due to their genetic proximity, chimpanzees share with human several diseases including bacterial, fungal and viral infections, such as candidiasis, acquired immune deficiency syndrome (aids), ebola virus disease. however, in its natural environment, chimpanzees are tolerant to several pathogens including simian immunodeficiency virus (siv), virus related to human immunodeficiency virus (hiv) that contribute to the emergence of opportunistic diseases such as microbial infections.201526498034
kin selection, social structure, gene flow, and the evolution of chimpanzees.hypotheses about chimpanzee social behavior, phylogeography, and evolution were evaluated by noninvasive genotyping of free-ranging individuals from 20 african sites. degrees of relatedness among individuals in one community were inferred from allele-sharing at eight nuclear simple sequence repeat (ssr) loci. males are related on the order of half-siblings, and homozygosity is significantly increased at several ssr loci compared to hardy-weinberg expectations. these data support the kin-selectio ...19947915048
orientation of occlusal contacts in the chimpanzee, pan troglodytes verus, deduced from scanning electron microscopic analysis of dental microwear patterns.analysis of dental microwear may be used to detect species differences in diet and to secure information about occlusal relationships and biomechanics of the jaw. microscratch-orientation data evaluated with reference to several hypotheses about functional, wear-related, sex and age influences on occlusal contacts indicated significant effects of facet type on scratch orientation, with less marked and sometimes paradoxical effects of molar wear and sex. age per se seemed not to be related to scr ...19846594090
[odintologic studies on the dentition of pan troglodytes verus].the examination of 90 pan troglodytes verus skulls from the collection of the institute of anthropology of the university of giessen did not reveal the existence of a tuberculum carabelli. against that a well marked cingulum of the upper molars could be observed. nearly half of the p2 showed two roots; one of the p1 had only one root. the two-rooted p2 are characteristic by a longitudinal groove on the buccal side, which may indicate bifurcation of the teeth. agenesia of teeth was found in 3.6% ...1979518043
ground-nesting by the chimpanzees of the nimba mountains, guinea: environmentally or socially determined?the chimpanzees (pan troglodytes verus) of the nimba mountains, guinea, west africa, commonly make both elaborate ("night") and simple ("day") nests on the ground. in this study we investigated which factors might influence ground-nesting in this population, and tested two ecological hypotheses: 1) climatic conditions, such as high wind speeds at high altitudes, may deter chimpanzees from nesting in trees; and 2) a lack of appropriate arboreal nesting opportunities may drive the chimpanzees to n ...200717146789
absence of frequent herpesvirus transmission in a nonhuman primate predator-prey system in the wild.emergence of viruses into the human population by transmission from nonhuman primates (nhps) represents a serious potential threat to human health that is primarily associated with the increased bushmeat trade. transmission of rna viruses across primate species appears to be relatively frequent. in contrast, dna viruses appear to be largely host specific, suggesting low transmission potential. herein, we use a primate predator-prey system to study the risk of herpesvirus transmission between dif ...201323885068
savanna chimpanzees, pan troglodytes verus, hunt with tools.although tool use is known to occur in species ranging from naked mole rats [1] to owls [2], chimpanzees are the most accomplished tool users [3-5]. the modification and use of tools during hunting, however, is still considered to be a uniquely human trait among primates. here, we report the first account of habitual tool use during vertebrate hunting by nonhumans. at the fongoli site in senegal, we observed ten different chimpanzees use tools to hunt prosimian prey in 22 bouts. this includes im ...200717320393
evidence of cave use by savanna chimpanzees (pan troglodytes verus) at fongoli, senegal: implications for thermoregulatory behavior.much attention has been paid to how humans both adapt and acclimate to heat stress, primarily due to the relevance of these issues to hominid evolution in open plio-pleistocene environments. however, little is known about the responses of human's closest living relative, the chimpanzee (pan troglodytes), to similar environmental stressors. in southeastern senegal, one of the hottest and driest habitats that chimpanzees (p. t. verus) live in today, apes rely on behavioral mechanisms of dealing wi ...200717624495
anthrax kills wild chimpanzees in a tropical rainforest.infectious disease has joined habitat loss and hunting as threats to the survival of the remaining wild populations of great apes. nevertheless, relatively little is known about the causative agents. we investigated an unusually high number of sudden deaths observed over nine months in three communities of wild chimpanzees (pan troglodytes verus) in the taï national park, ivory coast. here we report combined pathological, cytological and molecular investigations that identified bacillus anthraci ...200415269768
genotyping aids field study of unhabituated wild chimpanzees.prolonged habituation times for wild great apes delay the collection of behavioral and environmental data, sometimes for years. however, genotyping of noninvasively collected feces can provide useful socioecological information in the meantime. we tested this premise on an unhabituated wild population of western chimpanzees (pan troglodytes verus) at mont assirik, senegal. genotyping yielded information on kinship, group size, party size and composition, sex ratio, and ranging.200415195330
evidence for a complex demographic history of chimpanzees.to characterize patterns of genomic variation in central chimpanzees (pan troglodytes troglodytes) and gain insight into their evolution, we sequenced nine unlinked, intergenic regions, representing a total of 19,000 base pairs, in 14 individuals. when these dna sequences are compared with homologous sequences previously collected in humans and in western chimpanzees (pan troglodytes verus), nucleotide diversity is higher in central chimpanzees than in western chimpanzees or in humans. consisten ...200414963091
arboreal nesting as anti-predator adaptation by savanna chimpanzees (pan troglodytes verus) in southeastern senegal.chimpanzees (pan troglodytes) make nests for resting and sleeping, which is unusual for anthropoid primates but common to all great apes. arboreal nesting has been linked to predation pressure, but few studies have tested the adaptive nature of this behavior. we collected data at two chimpanzee study sites in southeastern senegal that differed in predator presence to test the hypothesis that elevated sleeping platforms are adaptations for predator defense. at assirik in the parc national du niok ...200818161774
long-term reciprocation of grooming in wild west african chimpanzees.humans are well known for their ability to keep track of social debts over extended periods of time, and for their tendency to preferentially cooperate with closely bonded partners. non-human primates have been shown to cooperate with kin and non-kin, and reciprocate helpful acts. however, there is ongoing debate over whether they keep track of previous interactions and, if so, whether they can do it over extended periods of time, or are constrained to finalize exchanges within a single encounte ...200918957365
dental microwear of griphopithecus alpani.the examination of microscopic dental wear allows inferences to be made about diet in extinct species. this study reconstructs the diet of griphopithecus alpani, a 15 ma fossil hominoid from the miocene site of pa┼čalar in north-western turkey, using scanning electron microscopy (sem) to examine the microscopic wear on its molar teeth. the microwear patterns of griphopithecus are compared with those of three extant hominoid taxa-gorilla gorilla gorilla, pan troglodytes verus, and pongo pygmaeus p ...19999924132
african great apes are naturally infected with roseoloviruses closely related to human herpesvirus 7.primates are naturally infected with herpesviruses. during the last 15 years, the search for homologues of human herpesviruses in nonhuman primates allowed the identification of numerous viruses belonging to the different herpesvirus subfamilies and genera. no simian homologue of human herpesvirus 7 (hhv7) has been reported to date. to investigate the putative existence of hhv7-like viruses in african great apes, we applied the consensus-degenerate hybrid oligonucleotide primers (codehop) progra ...201425187544
morphological variation in adult chimpanzees (pan troglodytes verus) of the taï national park, côte d'ivoire.twenty five adult chimpanzee skeletons (pan troglodytes verus) of known age and sex (15 females, 10 males) from a long-term study site in taï national park, cote d'ivoire present new data on variation. these skeletons provide a rare opportunity to measure the cranium and postcranium from the same individuals. we compare measurements and indices of the taï sample with those of relatively complete pan troglodytes schweinfurthii skeletons from gombe national park, tanzania. measurements of pan pani ...200817786999
analysis of sea almond (terminalia catappa) cracking sites used by wild burmese long-tailed macaques (macaca fascicularis aurea).nut-cracking is shared by all non-human primate taxa that are known to habitually use percussive stone tools in the wild: robust capuchins (sapajus spp.), western chimpanzees (pan troglodytes verus), and burmese long-tailed macaques (macaca fascicularis aurea). despite opportunistically processing nuts, burmese long-tailed macaques predominantly use stone tools to process mollusks in coastal environments. here, we present the first comprehensive survey of sea almond (terminalia catappa) nut-crac ...201728056164
ecological context of savanna chimpanzee (pan troglodytes verus) termite fishing at fongoli, senegal.chimpanzees (pan troglodytes verus) at fongoli, senegal, consume termites year-round. understanding the ecological context behind this behavior is especially important in light of the environmental conditions at fongoli. this mosaic savanna habitat is one of the hottest and driest sites where chimpanzees have been studied. two genera and four species of termites were found in association with tools used by chimpanzees in a sample of 124 termite mounds that were monitored. the chimpanzees of fong ...200818288689
chaînes opératoires and resource-exploitation strategies in chimpanzee (pan troglodytes) nut cracking.we apply archaeological methods to extend our knowledge of chimpanzee material culture. the chaîne opératoire conceptual framework, as introduced by ethnography, established technology as a phased process. prehistoric archaeology adopted this concept to elucidate technological variability in tool-making procedures, based on knowledge of tool functions or subsistence patterns. we focused on the detection of operational sequences by wild chimpanzees (pan troglodytes verus) when nut cracking with l ...200818359504
significant differentiation in the apolipoprotein(a)/lipoprotein(a) trait between chimpanzees from western and central africa.elevated lipoprotein(a) (lp(a)) plasma concentrations are a risk factor for cardiovascular disease in humans, largely controlled by the lpa gene encoding apolipoprotein(a) (apo(a)). lp(a) is composed of low-density lipoprotein (ldl) and apo(a) and restricted to catarrhini. a variable number of kringle iv (kiv) domains in lpa lead to a size polymorphism of apo(a) that is inversely correlated with lp(a) concentrations. smaller apo(a) isoforms and higher lp(a) levels in central chimpanzees (pan tro ...201728671714
frequent foamy virus infection in free-living chimpanzees of the taï national park (côte d'ivoire).foamy viruses are frequently found in non-human primates and apes in captivity. however, data on simian foamy virus (sfv) infection in apes from the wild are limited. necropsy specimens were collected from 14 west african chimpanzees (pan troglodytes verus) from three communities in the taï national park, côte d'ivoire. pcr analysis revealed sfv-related int- and env-specific sequences in 12/14 chimpanzees. two young chimpanzees were not infected. plasma from 'pcr-positive' chimpanzees reacted ag ...200919141461
phylogenetic analysis of troglodytella abrassarti isolated from chimpanzees (pan troglodytes verus) in the wild and in captivity. 200819164884
forest chimpanzees (pan troglodytes verus) remember the location of numerous fruit trees.it is assumed that spatial memory contributes crucially to animal cognition since animals' habitats entail a large number of dispersed and unpredictable food sources. spatial memory has been investigated under controlled conditions, with different species showing and different conditions leading to varying performance levels. however, the number of food sources investigated is very low compared to what exists under natural conditions, where food resources are so abundant that it is difficult to ...200919484488
social influences on ant-dipping acquisition in the wild chimpanzees (pan troglodytes verus) of bossou, guinea, west africa.we currently have little understanding of the influence of learning opportunity, whether social or environmental, and maternal role on tool-use acquisition in young wild chimpanzees. this study aims to fill this gap by focusing on the acquisition of ant-dipping among chimpanzees of bossou, guinea. ant-dipping is a hazardous tool-use behaviour aimed at army ants (dorylus spp.). bossou chimpanzees target these ants both at nests (high risk) and trails (low risk) and employ two techniques to consum ...200919685087
isotopic ecology and dietary profiles of liberian chimpanzees.an extensive suite of isotopic data (delta(13)c, delta(15)n, and delta(18)o) from enamel apatite and bone collagen of adult male and female wild chimpanzees establishes baseline values for pan troglodytes verus in a primary rainforest setting. the ganta chimpanzee sample derives from a restricted region in northern liberia. diet is examined using stable light isotopes at three life stages-infant, young juvenile, and adult-and developmental differences are investigated within and between individu ...201019796791
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.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 ...201020027607
genome sequences of polyomaviruses from the wild-living red colobus (piliocolobus badius) and western chimpanzee (pan troglodytes verus).we identified with pcr and sequencing the full genomes of the recently discovered pan troglodytes verus polyomavirus 8 and piliocolobus badius polyomavirus 2 in a western chimpanzee and a western red colobus free-ranging in taï national park of côte d'ivoire.201627738028
attacks on local persons by chimpanzees in bossou, republic of guinea: long-term perspectives.attacks on humans by nonhuman primates are one of the most serious causes of human-primate conflict, and strongly influence people's perceptions and tolerance of nonhuman primates. despite their importance, systematic and extensive records of such attacks are rare. here, we report the attacks that occurred on local persons by chimpanzees (pan troglodytes verus) at bossou, republic of guinea, from 1995 to 2009. there have been a total of 11 attacks during this period, the majority of which were d ...201020034050
insectivory of savanna chimpanzees (pan troglodytes verus) at fongoli, senegal.little is known about the behavior of chimpanzees living in savanna-woodlands, although they are of particular interest to anthropologists for the insight they can provide regarding the ecological pressures affecting early hominins living in similar habitats. fongoli, senegal, is the first site where savanna chimpanzees have been habituated for observational data collection and is the hottest and driest site where such observation of chimpanzees occurs today. previously, indirect evidence sugges ...201121484757
gastrointestinal symbionts of chimpanzees in cantanhez national park, guinea-bissau with respect to habitat fragmentation.one of the major factors threatening chimpanzees (pan troglodytes verus) in guinea-bissau is habitat fragmentation. such fragmentation may cause changes in symbiont dynamics resulting in increased susceptibility to infection, changes in host specificity and virulence. we monitored gastrointestinal symbiotic fauna of three chimpanzee subpopulations living within cantanhez national park (cnp) in guinea bissau in the areas with different levels of anthropogenic fragmentation. using standard coprosc ...201323776090
feeding in fear? how adult male western chimpanzees (pan troglodytes verus) adjust to predation and savanna habitat pressures.we evaluated risk-sensitive foraging in adult male western chimpanzees (pan troglodytes verus) occupying a savanna environment at fongoli, senegal. the aim of this study was to determine how the risks of predation and heat stress influenced their behavior while feeding on a key food, fruit of the baobab tree (adansonia digitata).201728369733
feeding ecology of chimpanzees (pan troglodytes verus) inhabiting a forest-mangrove-savanna-agricultural matrix at caiquene-cadique, cantanhez national park, guinea-bissau.with rising conversion of "natural" habitat to other land use such as agriculture, nonhuman primates are increasingly exploiting areas influenced by people and their activities. despite the conservation importance of understanding the ways in which primates modify their behavior to human pressures, data are lacking, even for well-studied species. using systematically collected data (fecal samples, feeding traces, and direct observations), we examined the diet and feeding strategies of an unhabit ...201525800459
chimpanzee oil-palm use in southern cantanhez national park, guinea-bissau.cantanhez national park in southern guinea-bissau is a mosaic of forest, mangrove, savanna, and agricultural fields, with a high prevalence of oil-palm trees (elaeis guineensis). it hosts many different animal species, including the chimpanzee (pan troglodytes verus). very little is known about the ecology of chimpanzees inhabiting this area. the main aims of this study were to evaluate chimpanzee nesting behavior, define trends of habitat use, and estimate chimpanzee density in four separate fo ...201121259301
chimpanzees routinely fish for algae with tools during the dry season in bakoun, guinea.wild chimpanzees regularly use tools, made from sticks, leaves, or stone, to find flexible solutions to the ecological challenges of their environment. nevertheless, some studies suggest strong limitations in the tool-using capabilities of chimpanzees. in this context, we present the discovery of a newly observed tool-use behavior in a population of chimpanzees (pan troglodytes verus) living in the bakoun classified forest, guinea, where a temporary research site was established for 15 months. b ...201727813136
pre-columbian monkey tools.stone tools reveal worldwide innovations in human behaviour over the past three million years [1]. however, the only archaeological report of pre-modern non-human animal tool use comes from three western chimpanzee (pan troglodytes verus) sites in côte d'ivoire, aged between 4.3 and 1.3 thousand years ago (kya) [2]. this anthropocentrism limits our comparative insight into the emergence and development of technology, weakening our evolutionary models [3]. here, we apply archaeological techniques ...201627404235
how many landmarks? assessing the classification accuracy of pan lower molars using a geometric morphometric analysis of the occlusal basin as seen at the enamel-dentine junction.previous research has demonstrated that species and subspecies of extant chimpanzees and bonobos can be distinguished on the basis of the shape of enamel-dentine junction of lower molar crowns. thus, there is potential for fossil taxa, particularly fossil hominins, to be distinguished at similar taxonomic levels using lower molar crown morphology. new imaging techniques allow for the collection of large amounts of shape data, but it is not clear whether taxonomic distinctiveness increases with t ...200919828964
discrimination of extant pan species and subspecies using the enamel-dentine junction morphology of lower molars.previous research has demonstrated that species and subspecies of extant chimpanzees and bonobos can be distinguished on the basis of the shape of their molar crowns. thus, there is potential for fossil taxa, particularly fossil hominins, to be distinguished at similar taxonomic levels using molar crown morphology. unfortunately, due to occlusal attrition, the original crown morphology is often absent in fossil teeth, and this has limited the amount of shape information used to discriminate homi ...200919382140
comparative locomotor behavior of chimpanzees and bonobos: the influence of morphology on locomotion.results from a 10 month study of adult male and female bonobos (pan paniscus) in the lomako forest, zaire, and those from a 7 month study of adult male and female chimpanzees in the tai forest, ivory coast (pan troglodytes verus), were compared in order to determine whether there are species differences in locomotor behavior and substrate use and, if so, whether these differences support predictions made on the basis of interspecific morphological differences. results indicate that bonobos are m ...19938512056
persistent anthrax as a major driver of wildlife mortality in a tropical rainforest.anthrax is a globally important animal disease and zoonosis. despite this, our current knowledge of anthrax ecology is largely limited to arid ecosystems, where outbreaks are most commonly reported. here we show that the dynamics of an anthrax-causing agent, bacillus cereus biovar anthracis, in a tropical rainforest have severe consequences for local wildlife communities. using data and samples collected over three decades, we show that rainforest anthrax is a persistent and widespread cause of ...201728770842
invention and modification of a new tool use behavior: ant-fishing in trees by a wild chimpanzee (pan troglodytes verus) at bossou, guinea.wild chimpanzees are known to have a different repertoire of tool use unique to each community. for example, "ant-dipping" is a tool use behavior known in several chimpanzee communities across africa targeted at driver ants (dorylus spp.) on the ground, whereas "ant-fishing," which is aimed at carpenter ants (camponotus spp.) in trees, has primarily been observed among the chimpanzees of mahale in tanzania. although the evidence for differences between field sites is accumulating, we have little ...200818459112
the critically endangered western chimpanzee declines by 80.african large mammals are under extreme pressure from unsustainable hunting and habitat loss. certain traits make large mammals particularly vulnerable. these include late age at first reproduction, long inter-birth intervals, and low population density. great apes are a prime example of such vulnerability, exhibiting all of these traits. here we assess the rate of population change for the western chimpanzee, pan troglodytes verus, over a 24-year period. as a proxy for change in abundance, we u ...201728671715
thrombotic thrombocytopenic purpura related to adamts13 deficiency, and successful treatment in a chimpanzee (pan troglodytes verus).a 27-year-old male chimpanzee (pan troglodytes verus) developed signs of thrombotic thrombocytopenic purpura (ttp). adamts13 deficiency appeared to be the cause of disease. after treatment with high-dose prednisone, haematological values and clinical signs recovered. this is the first description of spontaneous ttp associated with adamts13 deficiency in a non-human primate.201728547839
activity and habitat use of chimpanzees (pan troglodytes verus) 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. c ...201728546651
an empirical evaluation of camera trapping and spatially explicit capture-recapture models for estimating chimpanzee density.empirical validations of survey methods for estimating animal densities are rare, despite the fact that only an application to a population of known density can demonstrate their reliability under field conditions and constraints. here, we present a field validation of camera trapping in combination with spatially explicit capture-recapture (secr) methods for enumerating chimpanzee populations. we used 83 camera traps to sample a habituated community of western chimpanzees (pan troglodytes verus ...201728267880
fluid dipping technology of chimpanzees in comoé national park, ivory coast.over a 6 month period during the dry season, from the end of october 2014 to the beginning of may 2015, we studied tool use behavior of previously unstudied and non-habituated savanna chimpanzees (pan troglodytes verus) living in the comoé national park, ivory coast (ci). we analyzed all the stick tools and leaf-sponges found that the chimpanzees used to forage for ants, termites, honey, and water. we found a particular behavior to be widespread across different chimpanzee communities in the par ...201728002878
chimpanzees in an anthropogenic landscape: examining food resources across habitat types at bossou, guinea, west africa.many primate populations occur outside protected areas in fragmented anthropogenic landscapes. empirical data on the ecological characteristics that define an anthropogenic landscape are urgently required if conservation initiatives in such environments are to succeed. the main objective of our study was to determine the composition and availability of chimpanzee (pan troglodytes verus) food resources across fine spatial scales in the anthropogenic landscape of bossou, guinea, west africa. we ex ...201627332064
y-chromosome structural diversity in the bonobo and chimpanzee lineages.the male-specific regions of primate y-chromosomes (msy) are enriched for multi-copy genes highly expressed in the testis. these genes are located in large repetitive sequences arranged as palindromes, inverted-, and tandem repeats termed amplicons. in humans, these genes have critical roles in male fertility and are essential for the production of sperm. the structure of human and chimpanzee amplicon sequences show remarkable difference relative to the remainder of the genome, a difference that ...201627358426
placentophagy in wild chimpanzees (pan troglodytes verus) at bossou, guinea.despite intensive observation of nonhuman great apes during long-term field studies, observations of great ape births in the wild are rare. research on wild chimpanzees (pan troglodytes verus) at bossou in the republic of guinea has been ongoing for 35 years, yet chimpanzee parturitions have been observed on only two occasions. here we provide information regarding both chimpanzee births, with detailed information from the close observation of one. during this birth, the mother built a day nest ...201626769192
the effectiveness of using carbonate isotope measurements of body tissues to infer diet in human evolution: evidence from wild western chimpanzees (pan troglodytes verus).changes in diet throughout hominin evolution have been linked with important evolutionary changes. stable carbon isotope analysis of inorganic apatite carbonate is the main isotopic method used to reconstruct fossil hominin diets; to test its effectiveness as a paleodietary indicator we present bone and enamel carbonate carbon isotope data from a well-studied population of modern wild western chimpanzees (pan troglodytes verus) of known sex and age from taï, cote d'ivoire. we found a significant ...201526553819
tools to tipple: ethanol ingestion by wild chimpanzees using leaf-sponges.african apes and humans share a genetic mutation that enables them to effectively metabolize ethanol. however, voluntary ethanol consumption in this evolutionary radiation is documented only in modern humans. here, we report evidence of the long-term and recurrent ingestion of ethanol from the raffia palm (raphia hookeri, arecaceae) by wild chimpanzees (pan troglodytes verus) at bossou in guinea, west africa, from 1995 to 2012. chimpanzees at bossou ingest this alcoholic beverage, often in large ...201526543588
male-mediated gene flow in patrilocal primates.many group-living species display strong sex biases in dispersal tendencies. however, gene flow mediated by apparently philopatric sex may still occur and potentially alters population structure. in our closest living evolutionary relatives, dispersal of adult males seems to be precluded by high levels of territoriality between males of different groups in chimpanzees, and has only been observed once in bonobos. still, male-mediated gene flow might occur through rare events such as extra-group m ...201121747938
mother-offspring transmission and age-dependent accumulation of simian foamy virus in wild chimpanzees.simian foamy viruses (sfvs) are thought to infect virtually any adult nonhuman primate (nhp). while many data have accumulated about patterns of codivergence with their hosts and cross-species transmission events, little is known about the modalities of sfv transmission within nhp species, especially in the wild. here we provide a detailed investigation of the dynamics of sfv circulation in a wild community of western chimpanzees (pan troglodytes verus). we demonstrate that mother-offspring (ver ...201323449796
dental calculus evidence of taï forest chimpanzee plant consumption and life history transitions.dental calculus (calcified dental plaque) is a source of multiple types of data on life history. recent research has targeted the plant microremains preserved in this mineralised deposit as a source of dietary and health information for recent and past populations. however, it is unclear to what extent we can interpret behaviour from microremains. few studies to date have directly compared the microremain record from dental calculus to dietary records, and none with long-term observation dietary ...201526481858
new evidence on the tool-assisted hunting exhibited by chimpanzees (pan troglodytes verus) in a savannah habitat at fongoli, sénégal.for anthropologists, meat eating by primates like chimpanzees (pan troglodytes) warrants examination given the emphasis on hunting in human evolutionary history. as referential models, apes provide insight into the evolution of hominin hunting, given their phylogenetic relatedness and challenges reconstructing extinct hominin behaviour from palaeoanthropological evidence. among chimpanzees, adult males are usually the main hunters, capturing vertebrate prey by hand. savannah chimpanzees (p. t. v ...201526064638
unconstrained cranial evolution in neandertals and modern humans compared to common chimpanzees.a variety of lines of evidence support the idea that neutral evolutionary processes (genetic drift, mutation) have been important in generating cranial differences between neandertals and modern humans. but how do neandertals and modern humans compare with other species? and how do these comparisons illuminate the evolutionary processes underlying cranial diversification? to address these questions, we used 27 standard cranial measurements collected on 2524 recent modern humans, 20 neandertals a ...201526468243
let bone and muscle talk together: a study of real and virtual dissection and its implications for femoral musculoskeletal structure of chimpanzees.proximal femoral morphology and associated musculature are of special relevance to the understanding of hominoid locomotor systems. knowledge of bone-muscle correspondence in extant hominoids forms an important comparative basis for inferring structure-function relationships in fossil hominids. however, there is still a lack of consensus on the correspondence between muscle attachment sites and surface morphology of the proximal femoral diaphysis in chimpanzees. two alternative observations have ...201525601190
"missing perikymata"--fact or fiction? a study on chimpanzee (pan troglodytes verus) canines.recently, a lower than expected number of perikymata between repetitive furrow-type hypoplastic defects has been reported in chimpanzee canines from the fongoli site, senegal (skinner and pruetz: am j phys anthropol 149 (2012) 468-482). based on an observation in a localized enamel fracture surface of a canine of a chimpanzee from the taï forest (ivory coast), these authors inferred that a nonemergence of striae of retzius could be the cause for the "missing perikymata" phenomenon in the fongoli ...201525693508
should i stay or should i go? initiation of joint travel in mother-infant dyads of two chimpanzee communities in the wild.it is well established that great apes communicate via intentionally produced, elaborate and flexible gestural means. yet relatively little is known about the most fundamental steps into this communicative endeavour-communicative exchanges of mother-infant dyads and gestural acquisition; perhaps because the majority of studies concerned captive groups and single communities in the wild only. here, we report the first systematic, quantitative comparison of communicative interactions of mother-inf ...201626833496
primate archaeology reveals cultural transmission in wild chimpanzees (pan troglodytes verus).recovering evidence of past human activities enables us to recreate behaviour where direct observations are missing. here, we apply archaeological methods to further investigate cultural transmission processes in percussive tool use among neighbouring chimpanzee communities in the taï national park, côte d'ivoire, west africa. differences in the selection of nut-cracking tools between neighbouring groups are maintained over time, despite frequent female transfer, which leads to persistent cultur ...201526483527
taï chimpanzees use botanical skills to discover fruit: what we can learn from their mistakes.fruit foragers are known to use spatial memory to relocate fruit, yet it is unclear how they manage to find fruit in the first place. in this study, we investigated whether chimpanzees (pan troglodytes verus) in the taï national park make use of fruiting synchrony, the simultaneous emergence of fruit in trees of the same species, which can be used together with sensory cues, such as sight and smell, to discover fruit. we conducted observations of inspections, the visual checking of fruit availab ...201323576098
stable isotope evidence of meat eating and hunting specialization in adult male chimpanzees.observations of hunting and meat eating in our closest living relatives, chimpanzees (pan troglodytes), suggest that among primates, regular inclusion of meat in the diet is not a characteristic unique to homo. wild chimpanzees are known to consume vertebrate meat, but its actual dietary contribution is, depending on the study population, often either unknown or minimal. constraints on continual direct observation throughout the entire hunting season mean that behavioral observations are limited ...201323530185
premolar root morphology and metric variation in pan troglodytes verus.premolar root form remains an important taxonomic character in hominin alpha taxonomy. variation in detailed aspects of root structure remains poorly characterized in extant apes. this limited comparative context hinders evaluations of the significance of root form variation in hominin systematics. using micro-computed tomography we examine morphological variation in premolars in 51 (n = 128 premolars) west african chimpanzees (pan troglodytes verus). we categorize premolar root/canal form and n ...201323460305
a previously undiscovered group of chimpanzees (pan troglodytes verus) is observed living in the tonkolili district of sierra leone.a previously undocumented group of wild chimpanzees (pan troglodytes verus) was recently discovered along the pampana river in the tonkolili district of sierra leone. based on interviews from local residents (n = 6), we estimate the group size to be approximately 30 individuals. though this population does not show up in the most recent census of chimpanzees in sierra leone, it concurs with findings that indicate most of the chimpanzees in sierra leone live scattered throughout the country along ...201323447116
population status of pan troglodytes verus in lagoas de cufada natural park, guinea-bissau.the western chimpanzee, pan troglodytes verus, has been classified as endangered on the iucn red list since 1988. intensive agriculture, commercial plantations, logging, and mining have eliminated or degraded the habitats suitable for p. t. verus over a large part of its range. in this study we assessed the effect of land-use change on the population size and density of chimpanzees at lagoas de cufada natural park (lcnp), guinea-bissau. we further explored chimpanzee distribution in relation to ...201323940766
age-related effects on malaria parasite infection in wild chimpanzees.wild great apes are widely infected with a number of malaria parasites (plasmodium spp.). yet, nothing is known about the biology of these infections in the wild. using faecal samples collected from wild chimpanzees, we investigated the effect of age on plasmodium spp. detection rates. the data show a strong association between age and malaria parasite positivity, with significantly lower detection rates in adults. this suggests that, as in humans, individuals reaching adulthood have mounted an ...201323720517
first gis analysis of modern stone tools used by wild chimpanzees (pan troglodytes verus) in bossou, guinea, west africa.stone tool use by wild chimpanzees of west africa offers a unique opportunity to explore the evolutionary roots of technology during human evolution. however, detailed analyses of chimpanzee stone artifacts are still lacking, thus precluding a comparison with the earliest archaeological record. this paper presents the first systematic study of stone tools used by wild chimpanzees to crack open nuts in bossou (guinea-conakry), and applies pioneering analytical techniques to such artifacts. automa ...201525793642
developmental defects in the teeth of three wild chimpanzees from the taï forest.developmental defects in teeth (accentuated lines and hypoplasias) have played a critical role in studies of childhood disease, nutrition, weaning, environmental variation, and early mortality. while these enigmatic structures have been lauded for their potential insights into human evolution, few studies have examined defects in individuals of known histories.201525820182
supraorbital development in chimpanzees, macaques and baboons.macroscopic and histological parameters are considered in an analysis of bone formation in the supraorbital region of macaques (macaca mulatta), baboons (papio cynocephalus anubis), and chimpanzees (pan troglodytes verus). results indicate that post-natal osteogenesis of the supraorbital segment of the frontal bone in these primates occurs as a cyclic phenomenon that coincides wth dental eruption patterns.19807431378
bayesian computation and model selection without likelihoods.until recently, the use of bayesian inference was limited to a few cases because for many realistic probability models the likelihood function cannot be calculated analytically. the situation changed with the advent of likelihood-free inference algorithms, often subsumed under the term approximate bayesian computation (abc). a key innovation was the use of a postsampling regression adjustment, allowing larger tolerance values and as such shifting computation time to realistic orders of magnitude ...201019786619
termite fishing laterality in the fongoli savanna chimpanzees (pan troglodytes verus): further evidence of a left hand preference.whether nonhuman primates show population-level handedness is a topic of much scientific debate. a previous study of handedness for termite fishing reported population-level left handedness in the chimpanzees from gombe national park, tanzania. in the current study, we examined whether similar hand preferences were evident in a savanna-dwelling chimpanzee population with regards to termite fishing. hand preference data were collected for 27 chimpanzees from february 2007 through july 2008 and no ...201223129227
reconstruction of periodicity of repetitive linear enamel hypoplasia from perikymata counts on imbricational enamel among dry-adapted chimpanzees (pan troglodytes verus) from fongoli, senegal.periodicity of repetitive linear enamel hypoplasia (rleh) in apes from high latitudes with single wet and dry seasons annually has not been described. we reconstruct periodicity and duration of rleh in canine teeth from three recently deceased chimpanzees from fongoli, senegal with a marked seven-month dry season. high-resolution dental molds were taken in the field for magnified imaging with digital microscopy. photomontages allowed counting of perikymata between episodes of rleh for reconstruc ...201223041791
a fine-scale chimpanzee genetic map from population sequencing.to study the evolution of recombination rates in apes, we developed methodology to construct a fine-scale genetic map from high-throughput sequence data from 10 western chimpanzees, pan troglodytes verus. compared to the human genetic map, broad-scale recombination rates tend to be conserved, but with exceptions, particularly in regions of chromosomal rearrangements and around the site of ancestral fusion in human chromosome 2. at fine scales, chimpanzee recombination is dominated by hotspots, w ...201222422862
wild chimpanzees plan their breakfast time, type, and location.not all tropical fruits are equally desired by rainforest foragers and some fruit trees get depleted more quickly and carry fruit for shorter periods than others. we investigated whether a ripe-fruit specialist, the chimpanzee (pan troglodytes verus), arrived earlier at breakfast sites with very ephemeral and highly sought-after fruit, like figs, than sites with less ephemeral fruit that can be more predictably obtained throughout the entire day. we recorded when and where five adult female chim ...201425349399
chimpanzees prey on army ants at seringbara, nimba mountains, guinea: predation patterns and tool use characteristics.chimpanzees are renowned for their use of foraging tools in harvesting social insects and some populations use tools to prey on aggressive army ants (dorylus spp.). tool use in army ant predation varies across chimpanzee study sites with differences in tool length, harvesting technique, and army ant species targeted. however, surprisingly little is known about the detailed ecology of army ant predation. we studied army ant predation by chimpanzees (pan troglodytes verus) at the seringbara study ...201525315798
the extent of cultural variation between adjacent chimpanzee (pan troglodytes verus) communities; a microecological approach.chimpanzees show cultural differences among populations across africa but also between neighboring communities. the extent of these differences among neighbors, however, remains largely unknown. comparing three neighboring chimpanzee community in the taï national park, côte d'ivoire, we found 27 putative cultural traits, including tool use, foraging, social interaction, communication and hunting behavior, exceeding by far previously known diversity. as foraging behavior is predominantly influenc ...201525256960
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