Body weights of wild chimpanzees (Pan troglodytes schweinfurthii) of the Mahale Mountains National Park, Tanzania

Ten male and nine female habituated chimpanzees (Pan troglodytes schweinfurthii) in the Kasoje area of the Mahale Mountains National Park, Tanzania, were weighed intermittently between December 1973 and March 1980 by luring them up a rope hung on a spring balance: six adult males averaged 42.0 kg and eight adult females 35.2 kg. Seasonal change in body weight was recognized at least partially; body weights tended to decrease in the later part of the wet season presumably because of food shortage in the middle of the wet season. Comparison of body weight among three populations of the same subspecies suggests that adult female chimpanzees of Mahale appear to be heavier than those of the Gombe National Park, Tanzania, and that they seem to be similar to the forest-living counterparts of eastern Zaire. On the other hand, body weights of adult male chimpanzees from the three populations do not show significant differences. Perhaps feeding competition among adult females in a small, isolated habitat is more severe than that among adult males, which may result in the body weight reduction among adult female chimpanzees at Gombe.     

Utilization of space by adult and juvenile groups of captive chimpanzees (Pan troglodytes)

A systematic analysis of space utilization in the home enclosures of four adult and three juvenile social groups of chimpanzees (Pan troglodytes) was conducted at the Primate Foundation of Arizona. The locations of all members of each group (excluding nursing infants) were recorded several times per week over a 3-month period. Adult chimpanzees were observed significantly more often in small vs large cages, on upper vs lower levels, and near cage perimeters vs cage centers. Analyses of sex differences in adults revealed that adult females are largely responsible for these space use patterns; adult males show only a significantly higher usage of perimeter areas. Individual differences were found in the habitual use of certain enclosure sites. Juveniles show no spatial patterns with regard to the above parameters but appear to evenly use all available space. Both adults and juveniles were observed to be in contact with mesh barriers more often than with solid walls. These findings suggest important elements that should be incorporated into the caging design of captive chimpanzee facilities.     

The macronutrient composition of wild and cultivated plant foods of West African chimpanzees (Pan troglodytes verus) inhabiting an anthropogenic landscape

Agricultural expansion encroaches on tropical forests and primates in such landscapes frequently incorporate crops into their diet. Understanding the nutritional drivers behind crop-foraging can help inform conservation efforts to improve human-primate coexistence. This study builds on existing knowledge of primate diets in anthropogenic landscapes by estimating the macronutrient content of 24 wild and 11 cultivated foods (90.5% of food intake) consumed by chimpanzees (Pan troglodytes verus) at Bossou, Guinea, West Africa. We also compared the macronutrient composition of Bossou crops to published macronutrient measures of crops from Bulindi, Uganda, East Africa. The composition of wild fruits, leaves, and pith were consistent with previous reports for primate diets. Cultivated fruits were higher in carbohydrates and lower in insoluble fiber than wild fruits, while wild fruits were higher in protein. Macronutrient content of cultivated pith fell within the ranges of consumed wild pith. Oil palm food parts were relatively rich in carbohydrates, protein, lipids, and/or fermentable fiber, adding support for the nutritional importance of the oil palm for West African chimpanzees. We found no differences in the composition of cultivated fruits between Bossou and Bulindi, suggesting that macronutrient content alone does not explain differences in crop selection. Our results build on the current understanding of chimpanzee feeding ecology within forest-agricultural mosaics and provide additional support for the assumption that crops offer primates energetic benefits over wild foods.     

The relationship between forage material and levels of coprophagy in captive chimpanzees (Pan troglodytes)

Although coprophagy is practiced in the wild by chimpanzees (Pan troglodytes), it occurs more frequently and under more varied circumstances in captivity. This study was designed to determine if different forage materials and amount of residual undigested grain particles found in the feces might cause an increase in coprophagous behavior in those animals which already exhibited the behavior. A possible effect of availability of seed pits and fibrous leaves for “wadge” making, a typical chimpanzee behavior, on levels of coprophagy was also considered. Observations for coprophagous behavior were conducted on 65 juvenile, adolescent, and adult chimpanzees. Coprophagy levels were significantly lower with popcorn than either chicken scratch or sweet feed. A significant increase in coprophagy was noted for all weeks of forage types when tested against the wadge weeks. Residual grain content analysis showed no significant difference in coprophagous behavior between any of the testing conditions. Decreasing levels of coprophagous behaviors may be assisted by the provision of wadge materials. © 1992 Wiley-Liss, Inc.     

Nipple contact in captive black-faced chimpanzees (Pan t troglodytes [Blumenbach, 1779])

Three chimpanzee (Pan t troglodytes) mother-infant dyads were studied from months 3 to 11 of the infants' lives in order to obtain data on nipple contact. Three conclusions were obtained: (1) There were fluctuations in the time spent in nipple contact. (2) Both female offspring were in nipple position for less time than the male offspring. (3) Grooming of the infants by their mothers during nipple contact was observed more frequently in the mother-female offspring pairs.     

乌干达野生动物研究中心外来黑猩猩融入笼养群体的过程

1967至1997的30年间,生活在非洲热带地区自然栖息地的野生黑猩猩数量由60万降至不足20万,至今这个数字仍在减少,因此引起了全球的关注并急需要开展迁地保护。笼养黑猩猩与野外种群一样营群居生活,为了有效进行野生黑猩猩的迁地保护,将野外捕获的野生黑猩猩个体成功引入已在动物园的黑猩猩群体中十分必要。2004年10月至2005年3月,乌干达野生动物研究中心首先开展了这一实验。同时为更好地了解外来黑猩猩融入笼养群体的过程,2006年9月至2007年1月间收集其活动数据。选取5只黑猩猩个体并记录它们的食性、行为、体重变化及身体健康状况。除直接观察和记录外,与兽医和研究中心管理人员进行合作,以获取较多笼养个体的信息。我们发现,野生个体比笼养个体多病,因此影响了它们的取食、社会行为及活动水平。尽管笼养黑猩猩有人照料,但仍具备野生个体的行为,所以,理解外来黑猩猩融入笼养群体的过程对于黑猩猩的迁地保护和就地保护是非常重要的。     

Detection and molecular characterization of foamy viruses in Central African chimpanzees of the Pan troglodytes troglodytes and Pan troglodytes vellerosus subspecies

BACKGROUND: Foamy viruses are exogenous retroviruses that are highly endemic in non-human primates (NHPs). Recent studies, mainly performed in North America, indicated frequent simian foamy virus (SFV) infection in persons occupationally exposed to NHPs. This zoonotic infection was demonstrated mainly after bites by chimpanzees [Pan troglodytes (P. t.)] of the West African P. t. verus subspecies in primatology centers or zoos in the USA. METHODS: We studied 32 chimpanzees from the Central African subspecies P. t. troglodytes and P. t. vellerosus, originating from Cameroon (29 cases) or Gabon (3 cases). We screened first plasma or sera of the animals with a Western blot detecting the SFVs Gag doublet proteins. Then, we performed two nested polymerase chain reactions (PCRs) amplifying a fragment of the integrase and LTR regions and, finally, we made phylogenetical analyses on the sequences obtained from the integrase PCR products. RESULTS: By serological and/or molecular assays, we detected foamy viruses (FVs) infection in 14 chimpanzees. Sequence comparison and phylogenetic analyses of a 425 bp fragment of the integrase gene obtained for 10 of the 14 positive apes, demonstrated a wide diversity of new FVs strains that belong phylogenetically either to the P. t. troglodytes or P. t. vellerosus foamy viral clade. CONCLUSIONS: This study shows that chimpanzees living in these areas of Central Africa are infected by several specific foamy viruses. This raises, in such regions, the potential risk of a human retroviral infection of zoonotic origin linked to chimpanzees contacts, as already exemplified for STLV-1 and SIV infections.     

Positive reinforcement training affects hematologic and serum chemistry values in captive chimpanzees (Pan troglodytes)

Positive reinforcement training (PRT) techniques have received considerable attention for their stress reduction potential in the behavioral management of captive nonhuman primates. However, few published empirical studies have provided physiological data to support this position. To address this issue, PRT techniques were used to train chimpanzees (Pan troglodytes) to voluntarily present a leg for an intramuscular (IM) injection of anesthetic. Hematology and serum chemistry profiles were collected from healthy chimpanzees (n=128) of both sexes and various ages during their routine annual physical examinations over a 7-year period. Specific variables potentially indicative of acute stress (i.e., total white blood cell (WBC) counts, absolute segmented neutrophils (SEG), glucose (GLU) levels, and hematocrit (HCT) levels) were analyzed to determine whether the method used to administer the anesthetic (voluntary present for injection vs. involuntary injection) affected the physiological parameters. Subjects that voluntarily presented for an anesthetic injection had significantly lower mean total WBC counts, SEG, and GLU levels than subjects that were involuntarily anesthetized by more traditional means. Within-subjects analyses revealed the same pattern of results. This is one of the first data sets to objectively demonstrate that PRT for voluntary presentation of IM injections of anesthetic can significantly affect some of the physiological measures correlated with stress responses to chemical restraint in captive chimpanzees.     

Diet of wild chimpanzees (Pan troglodytes verus) at Mt. Assirik,Senegal: I. Composition

The composition of the diet of a savanna-living population of wild chimpanzees (Pan troglodytes verus) at Mt. Assirik in Senegal is presented. The study site had a prolonged dry season, high temperatures, and vegetation dominated by grasses. Data came from direct observation, fecal specimens, and feeding traces; thus, strict criteria for acceptance of the indirect data were specified. Composition of diet was given in terms of species and family of prey, parts eaten, life-form, type of habitat, and criteria for inclusion. Forty-three species of plants with 60 parts were eaten; mostly fruits, from trees, in woodland. Nine species of animal prey were eaten, mostly social insects. An additional 41 species of plants with 53 parts were classed as likely to be eaten by chimpanzees, mostly on the grounds of their being eaten by sympatric anthropoids. Overall, the diet of the apes at Mt. Assirik resembles that of this species elsewhere in Africa, but the size of the dietary repertoire seems small and the proportion of low-quality foodstuffs high. The latter are mostly time-consuming to collect or tedious to obtain or process, and include underground storage organs.     

Analysis of hematologic findings in healthy and sick adult chimpanzees (Pan troglodytes)

In order to assess the validity of interspecies extrapolation of hematological information, reference values obtained on 63 captive adult chimpanzees were compared with normal values for man. The discriminative power of both chimpanzee and human reference values was tested by the ability of each to identify abnormalities in the blood in 15 sick chimpanzees. The results indicated that human criteria could be applied to most chimpanzee red cell values but species differences were found in erythrocyte sedimentation rates and neutrophil counts.     

Variables influencing the origins of diverse abnormal behaviors in a large sample of captive chimpanzees (Pan troglodytes)

The developmental origin of abnormal behaviors is generally associated with early rearing environments that lack sufficient physical and sensory stimulation. However, other factors should also be considered. A large sample of captive chimpanzees (128 males and 140 females) was surveyed for the presence or absence of 18 abnormal behaviors. Origin variables included the subject's source (zoo, pet, performer, or laboratory), rearing (mother‐ or hand‐reared), and sex. Animals were assessed while held at the Primate Foundation of Arizona, University of Texas M. D. Anderson Cancer Center, or White Sands Research Center. There was a confound among origin variables; more hand‐reared animals than expected were from laboratories. Logistic regression tested the relationship of rearing and source, with sex as a secondary predictor variable, to each of the abnormal behaviors. There was no clear association between any abnormal behavior and source. However, for coprophagy, relative to animals from the laboratory, zoo animals tended to show a higher prevalence, while performers tended to show a lower prevalence (when rearing and sex were controlled). Rocking and self‐sucking were significantly more likely in hand‐reared animals. Coprophagy and depilation of self were significantly more likely in mother‐reared animals. When rearing and source were statistically controlled, the only significant sex difference was a higher prevalence of coprophagy in females and a higher prevalence of rocking in males. In a second, smaller sample of 25 males and 33 females from Southwest Foundation for Biomedical Research, no significant sex association was found for coprophagy, urophagy, rocking, or self‐depilation. In this second sample, coprophagy was also significantly more likely in mother‐reared than hand‐reared subjects. The association of some abnormal behaviors with mother‐rearing suggests that some form of social learning may be involved in the origin of some of these behavior patterns. This indicates that some abnormal behaviors may not be always be indicative of reduced psychological well‐being in captive chimpanzees. Am. J. Primatol. 48:15–29, 1999. © 1999 Wiley‐Liss, Inc.     

Tool use by wild chimpanzees (Pan troglodytes) to obtain termites (Macrotermes herus) in the Mahale Mountains,Tanzania

Wild chimpanzees (Pan troglodytes) used probes made of vegetation to fish for termites (Macrotermes herus) in the Mahale Mountains of western Tanzania. Data on both the artefacts and behavior associated with their use were recorded over a 5-month period. The chimpanzees of one unit group, B Group, were seen four times to use the tools to extract the insects from their mounds. A sample of 290 tools was collected and analyzed in terms of age, seasonality, length, width, class of raw materials, species, methods of making, extent of use, and damage incurred through use. There were differences across groups in tool use in feeding on termites; some could be related to biotic factors, but others appeared to be cultural differences.     

Fecal bacterial diversity of human‐habituated wild chimpanzees (Pan troglodytes schweinfurthii) at Mahale Mountains National Park,Western Tanzania

Although the intestinal flora of chimpanzees has not been studied, insight into this dynamic environment can be obtained through studies on their feces. We analyzed fecal samples from human‐habituated, wild chimpanzees at Mahale Mountains National Park, Tanzania, and compared microbial community profiles to determine if members of the same social group were similar. Between July and December 2007, we collected fresh fecal samples from 12 individuals: four juveniles, four adolescents, and four adults, including three parent–offspring pairs. Each sample was analyzed using Terminal‐Restriction Fragment Length Polymorphism of amplified 16S rRNA genes. Twelve different profiles were generated, having between 1 and 15 Terminal‐Restriction Fragments (T‐RFs). Overall, a total of 23 different T‐RFs were produced. Putative assignments of T‐RFs corresponded to the phyla Firmicutes (Clostridia, Bacilli, and Lactobacilli), Bacteroidetes, Tenericutes (Mollicutes Class), Actinobacteria, and Proteobacteria, as well as to uncultured or unidentified organisms. Firmicutes and Bacteroidetes phyla and Mollicutes Class were the most commonly assigned in 11, 8, and 8 of the samples, respectively, with this being the first report of Mollicutes in wild chimpanzees. Principal Components Analysis (PCA) revealed clustering of nine samples, and 80.5% of the diversity was accounted for by three samples. Morisita indices of community similarity ranged between 0.00 and 0.89, with dissimiliarity (<0.5) between most samples when compared two at a time. Our findings suggest that, although phylotypes are common among individuals, profiles among members of the same social group are host‐specific. We conclude that factors other than social group, such as kinship and age, may influence fecal bacterial profiles of wild chimpanzees, and recommend that additional studies be conducted. Am. J. Primatol. 72:566–574, 2010. © 2010 Wiley‐Liss, Inc.     

Sources of variation in the nesting behavior of chimpanzees (Pan troglodytes schweinfurthii) in the Budongo forest, Uganda

Data on nesting behavior and nests of the Sonso community of chimpanzees (Pan troglodytes schweinfurthii) living in the Budongo Forest, Uganda, were collected between October 1995 and December 1996. Analysis of the selection of nests shows a preference for particular tree species, especially Cynometra alexandri. Male chimpanzees nested lower than females. Day nests were found to be structurally simpler than night nests and were built in tree species used for feeding, at the same height as feeding activity. Day and night nests serve different functions, and should be clearly distinguished in studies of nesting behavior.     

“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 (“stepping-sticks”) and body (“seat-sticks”) protection against the painful thorns. This form of tool-using is culturally unique to the Tenkere chimpanzees, as at other sites where these apes have been observed eating parts of kapok trees, there are no published records of this tool technology. In three of the stepping-stick tool use incidents, the chimpanzee used the tool(s), held between their greater and lesser toes, in locomotion. This form of tool use is the first recorded case of habitually used tools that can be justifiably categorized as being “worn” by any known wild population of Pan troglodytes. Am J Primatol 41:45–52, 1997. © 1997 Wiley-Liss, Inc.     

Quantitative polymerase chain reaction analysis of DNA from noninvasive samples for accurate microsatellite genotyping of wild chimpanzees (Pan troglodytes verus)

Noninvasive samples are useful for molecular genetic analyses of wild animal populations. However, the low DNA content of such samples makes DNA amplification difficult, and there is the potential for erroneous results when one of two alleles at heterozygous microsatellite loci fails to be amplified. In this study we describe an assay designed to measure the amount of amplifiable nuclear DNA in low DNA concentration extracts from noninvasive samples. We describe the range of DNA amounts obtained from chimpanzee faeces and shed hair samples and formulate a new efficient approach for accurate microsatellite genotyping. Prescreening of extracts for DNA quantity is recommended for sorting of samples for likely success and reliability. Repetition of results remains extensive for analysis of microsatellite amplifications beginning from low starting amounts of DNA, but is reduced for those with higher DNA content.     

Factors affecting party size and composition of chimpanzees (Pan troglodytes verus) Bossou,Guinea

I studied the party sizes of western chimpanzees (Pan troglodytes verus)and factors assumed to affect them at Bossou, Republic of Guinea, West Africa. Party size is negatively correlated with feeding ratio, and larger parties tend to be formed in more dangerous situations (i.e. crossing roads with much traffic). When parties included estrous females, young (i.e., late juvenile and adolescent) males tended to forage with them, independently from their mothers. Lactating females with infants tended to spend more time alone, but the trend was not as apparent as it is in P. t. schweinfurthiat Gombe, Tanzania. These facts suggest that several factors, in addition to food availability, affect party formation, or fission-fusion, of chimpanzees. I also briefly discuss comparatively the pattern of party formation in P. paniscus.     

Extraction,PCR amplification,and sequencing of mitochondrial DNA from scent mark and feces in the giant panda

To expand the feasibility of applying simple, efficient, non-invasive DNA preparation methods using samples that can be obtained from giant pandas living in the wild, we investigated the use of scent markings and fecal samples. Giant panda–specific oligonucleotide primers were used to amplify a portion of the mitochondrial DNA control region as well as a portion of the mitochondrial DNA cytochrome b gene and tRNA^Thr gene region. A 196 base pair (bp) fragment in the control region and a 449 bp fragment in the cytochrome b gene and tRNA^Thr gene were successfully amplified. Sequencing of polymerase chain reaction (PCR) products demonstrated that the two fragments are giant panda sequences. Furthermore, under simulated field conditions we found that DNA can be extracted from fecal samples aged as long as 3 months. Our results suggest that the scent mark and fecal samples are simple, efficient, and easily prepared DNA sources. Zoo Biol 17:499–504, 1998. © 1998 Wiley-Liss, Inc.     

An apparatus and procedure for studying the choice component of foraging in a captive group of chimpanzees (Pan troglodytes)

An apparatus is described which was used to investigate the choice component of foraging in a captive group of chimpanzees maintained in a large, outdoor compound at the Yerkes Regional Primate Research Center Field Station. The utilization of more than one apparatus would allow the investigation of other ecological and psychological concepts in nonhuman primates housed under semi-natural conditions.