New Cases of Intergroup Violence Among Chimpanzees in Gombe National Park,Tanzania

Despite considerable attention to chimpanzee intergroup violence, the number of observed cases remains small. We report 4 cases of intergroup violence that occurred in Gombe National Park, Tanzania, between 1993 and 2002. We observed (3 cases) or inferred (1 case) males from the Kasekela community to attack members of their 2 neighboring communities: Mitumba and Kalande. In 1993, Kasekela males killed and ate a female infant from Mitumba. In 1998, Kasekela males captured 2 infants (sex unknown) from Kalande, one of which escaped and the other was killed and eaten. Also in 1998, Kasekela males attacked an adolescent male from Kalande. The victim was alive but severely injured by the end of the attack. The intensity and duration of the attack are comparable to other attacks that resulted in fatal injuries. In 2002, observers found the body of an adolescent male from Mitumba following an incursion by Kasekela males into the area. The injuries inflicted on the Mitumba male together with circumstantial evidence suggest that Kasekela males killed him. The attacks support the view that intergroup violence is a persistent feature of chimpanzee societies and that the primary benefit attackers gain from them is reduced competition for resources.     

An unusual incident of adoption in a wild chimpanzee (Pan troglodytes) population at Gombe National Park

Allomothering and adoption are well documented across primate species. Multiple hypotheses have been proposed to explain the evolution of such behavior according to the costs and benefits to the caregiver, mother, and infant. Permanent adoptions and allomothering have been observed in chimpanzees, but they typically involve the infants' siblings or nulliparous females. Here, I report a unique incident of adoption where an infant was adopted by its grandmother without the death of its mother. I conclude by considering how the adoption may have benefited the grandmother, mother, and infant.     

New Intercommunity Infanticides by the Chimpanzees of Ngogo,Kibale National Park,Uganda

Hostile intercommunity relations, including attacking and killing extra-community infants of both sexes have occurred at most wild chimpanzee sites. We describe three recent cases of intercommunity attacks on infants committed by members of the Ngogo chimpanzee community in Kibale National Park, Uganda. Two of the attacks resulted in confirmed infanticides while a third attack probably resulted in the infant's death. In common with previous accounts of chimpanzee infanticides, the attacks described here occurred during boundary patrols outside the Ngogo community's usual range, adult and adolescent males were the main participants, one infant was cannibalized after being killed, and the victims’ mothers did not accompany the attacking party back to the Ngogo range. However, the patrol parties during each infanticide were larger than before and included females from the Ngogo community. Our observations indirectly support both the range expansion and imbalance of power hypotheses, which address why and under which conditions chimpanzee intercommunity encounters lead to aggression. These cases of intercommunity infanticide add to the growing database of the phenomenon in wild chimpanzees.     

Severe Aggression Among Female Pan troglodytes schweinfurthii at Gombe National Park, Tanzania

Aggression is generally more severe between males than between females because males gain greater payoffs from escalated aggression. Males that successfully defeat rivals may greatly increase their access to fertile females. Because female reproductive success depends on long-term access to resources, competition between females is often sustained but low key because no single interaction leads to a high payoff. Nonetheless, escalated aggression can sometimes immediately improve a female’s reproductive success. Resisting new immigrants can reduce feeding competition, and infanticide of other females’ young can increase a female’s access to resources. East African chimpanzees live in fission-fusion communities in which females occupy overlapping core areas. Growing evidence indicates that reproductive success correlates with core area quality, and that females compete for long-term access to core areas. Here we document 5 new cases of severe female aggression in the context of such competition: 2 attacks by resident females on an immigrant female, a probable intracommunity infanticide, and 2 attacks on a female and her successive newborn infants by females whose core areas overlapped hers. The cases provide further evidence that females are occasionally as aggressive as males. Factors influencing the likelihood and severity of such attacks include rank and size differences and the presence of dependable allies. Counterstrategies to the threat of female aggression include withdrawing from others around the time of parturition and seeking male protection. We also discuss an unusual case of a female taking the newborn infant of another, possibly to protect it from a potentially infanticidal female.     

Variation over Time in Parasite Prevalence Among Free-ranging Chimpanzees at Gombe National Park,Tanzania

From January to September, 2005, we collected fecal samples from 60 chimpanzees at Gombe National Park, Tanzania and examined them for parasites. We compared current parasite prevalence data with previous studies to obtain a pattern of parasitism over time. There were considerable similarities in the parasite species composition and prevalence, although we noted some variations. Generally, parasite prevalence decreased over time, with the present prevalence being lower than in previous surveys. We identified 8 types of parasites, all of which had previously been documented in the chimpanzees of Gombe. Three nematodes — Oesophagostomum sp., Strongyloides fulleborni, and Abbreviata caucassica— occurred at higher prevalence (41.2–45.5%) but relatively lower than previous findings of 50–91%. We also diagnosed unidentified strongyles at a moderate prevalence (33%), lower than a previous record of 41%. Probstmayria gombensis occurred at relatively low prevalence (16.4%) vs. past observations (23–59%), while the prevalence of Trichuris sp. (7.3%) was closely similar to previous records of 5–9%. We also observed unidentified ciliate at 9% within the same range as in previous studies (5–28%). The prevalence of Troglodytella abrassarti was 78%, closely similar to previous findings of 75%. There was no significant variation in parasite prevalence between chimpanzees of the Kasekela community and those of the Mitumba community, although the former tended to have higher prevalence of helminths than the latter. The causes of the similarities and variations in parasite prevalence over time are discussed. The study provides baseline data for monitoring of chimpanzee health at Gombe.     

Poliomyelitis and skeletal asymmetry in Gombe chimpanzees

Skeletons of free-ranging chimpanzees from Gombe National Park, Tanzania allow assessment of the effects of long-term, unilateral upper limb paralysis due to the infectious viral disease, poliomyelitis. Comparison of left and right upper limb bone weights, lengths, joint areas, and diaphysial diameters between two adult females with long-term, partial paralysis and a group of unaffected adult Gombe chimpanzees show that the disease caused considerable asymmetries in the skeleton. Detailed analyses of mineral content and diaphysial cross-sectional geometry of the humerus in the affected females show individual differences. The analysis extends to consideration of bone-muscle relationships and peripheral and central nervous system involvement. For each individual, sex, estimated age at death, and behavioral information during life are known from field studies. The impact of the disease on survival and reproductive outcome of the affected individuals is discussed.     

Causes of death in the Kasekela chimpanzees of Gombe National Park, Tanzania

Understanding the rates and causes of mortality in wild chimpanzee populations has important implications for a variety of fields, including wildlife conservation and human evolution. Because chimpanzees are long-lived, accurate mortality data requires very long-term studies. Here, we analyze 47 years of data on the Kasekela community in Gombe National Park. Community size fluctuated between 38 and 60, containing 60 individuals in 2006. From records on 220 chimpanzees and 130 deaths, we found that the most important cause of mortality in the Kasekela community was illness (58% of deaths with known cause), followed by intraspecific aggression (20% of deaths with known cause). Previous studies at other sites also found that illness was the primary cause of mortality and that some epidemic disease could be traced to humans. As at other study sites, most deaths due to illness occurred during epidemics, and the most common category of disease was respiratory. Intraspecific lethal aggression occurred within the community, including the killing of infants by both males and females, and among adult males during the course of dominance-related aggression. Aggression between communities resulted in the deaths of at least five adult males and two adult females in the Kasekela and Kahama communities. The frequency of intercommunity violence appears to vary considerably among sites and over time. Intercommunity lethal aggression involving the Kasekela community was observed most frequently during two periods. Other less common causes of death included injury, loss of mother, maternal disability, and poaching.     

Body size and proportions in chimpanzees,with special reference toPan troglodytes schweinfurthii from Gombe National Park,Tanzania

Body weight, cranial capacity, linear and joint area data from ten free-ranging adult chimpanzees from Gombe National Park, Tanzania with known life histories allow study of variation in a local population and comparison to other populations ofPan troglodytes and toPan paniscus. Because individuals in the Gombe population are small compared to other common chimpanzees, they provide a useful comparison toPan paniscus. Body weight and some linear dimensions overlap withPan paniscus. However, cranial capacity, tooth size, and body proportions of Gombe individuals lie within the range of otherPan troglodytes and are distinct fromPan paniscus.     

Responses of chimpanzees to a recently dead community member at Gombe National Park, Tanzania

Chimpanzee responses to the death of a group member have rarely been observed in the wild and most instances involve infant deaths. One of the very few detailed accounts of a group's response to the death of an adult community member is from Gombe National Park, Tanzania, where Teleki [Folia Primatologica 20:81-94, 1973] observed the responses of 16 chimpanzees to an accidental death, none of whom touched the body. Now, almost 40 years later, we report on the behaviors of 16 (different) Gombe individuals to the recently dead body of an adult female community member. In stark contrast to Teleki's account, we observed individual chimpanzees' responses to range from curious observation and passive investigation (e.g. smelling and grooming) to the shaking, dragging, and frustrated beating of the body. Variation across demographic groups is described and may reflect individuals' past experience with death. The implications of our observations are discussed in the context of core morbidity traits shared between humans and chimpanzees.     

Hunting Behavior of Chimpanzees at Ngogo,Kibale National Park,Uganda

Chimpanzees (Pan troglodytes) prey on a variety of vertebrates, mostly on red colobus (Procolobus spp.) where the two species are sympatric. Variation across population occurs in hunting frequency and success, in whether hunting is cooperative, i.e., payoffs to individual hunters increase with group size, and in the extent to which hunters coordinate their actions in space and time, and in the impact of hunting on red colobus populations. Also, hunting frequency varies over time within populations, for reasons that are unclear. We present new data on hunting by chimpanzees at Ngogo, Kibale National Park, Uganda, and combine them with earlier data (Mitani and Watts, 1999, Am. J. Phys. Anthropol. 109: 439–454) to examine hunting frequency and success, seasonality, and cooperation. The Ngogo community is the largest and has the most males of any known community. Chimpanzees there mostly hunt red colobus and are much more successful and make many more kills per hunt than at other sites; they kill 6–12% of the red colobus population annually. The number of kills and the offtake of meat per hunt increase with the number of hunters, but per capita meat intake is independent of hunting party size; this suggests that cheating occurs in large parties. Some behavioral cooperation occurs. Hunting success and estimated meat intake vary greatly among males, partly due to dominance rank effects. The high overall success rate leads to relatively high average per capita meat intake despite the large number of consumers. The frequency of hunts and of hunting patrols varies positively with the availability of ripe fruit; this is the first quantitative demonstration of a relationship between hunting frequency and the availability of other food, and implies that the chimpanzees hunt most when they can easily meet energy needs from other sources. We provide the first quantitative support for the argument that variation in canopy structure influences decisions to hunt red colobus because hunts are easier where the canopy is broken.     

Tool Use by Chimpanzees at Ngogo,Kibale National Park,Uganda

Chimpanzees make and use a wide variety of tools in the wild. The size and composition of their toolkits vary considerably among populations and at least to some extent within them. Chimpanzees at several well documented sites mostly use tools in extractive foraging, and extractive tool use can substantially increase their foraging efficiency. They also use tools for hygiene and for several other purposes, including attracting the attention of conspecifics, as in leaf-clipping. Some of the interpopulation variation in toolkits results from ecological variation, but differences in the efficiency of social transmission, perhaps related to differences in social tolerance, presumably also contribute. I describe tool use by chimpanzees in an unusually large community at Ngogo, in Kibale National Park, Uganda. Researchers have described some tool use for the community previously, but this is the most extensive report and is based on observations over 11 yr. The Ngogo chimpanzees have a small toolkit and use tools rarely except in leaf-clipping displays and to clean body surfaces; notably, males often use leaf napkins to wipe their penes after copulation. Extractive tool use is rare and is limited mostly to leaf-sponging and, less often, honey-fishing. Social tolerance is not low at Ngogo, but use of tools for extractive foraging, in ways documented at other field sites, may have little potential to increase foraging efficiency. Future research will undoubtedly show more tool use by females, which were underrepresented in my observations, but will probably not document much increase in the toolkit or in the use of extractive tools.     

中国三江源国家公园与韩国智异山国家公园的对比研究

自1967年智异山被认定为韩国首个国家公园以来,韩国以国家公园为主体的自然保护地体系建设已历经50余年。这期间韩国在国家公园的建设中积累了大量经验,十分值得我国借鉴。选取我国首个国家公园体制试点——三江源国家公园和韩国首个国家公园——智异山国家公园为研究对象,对二者的管理现状进行了定性分析,并运用基于最优实践的国家公园管理能力评价方法对二者的管理能力进行了定量评价。研究表明:三江源国家公园的管理能力综合得分低于智异山国家公园,在体制建设、保障机制、资源环境管理、社区管理和科普教育五个方面均与智异山国家公园存在一定差距;智异山国家公园在资源本底调查、法制建设、多方参与、环境教育和游憩管理方面的管理能力十分突出,为三江源国家公园管理能力的提升提供了有益借鉴;三江源国家公园在生态补偿和制度约束方面具有比较优势,但在自然资源权属、资源本底调查、社区组织建设和游憩管理方面则亟待提升。在此基础上,针对三江源国家公园建设提出了强化科研支撑、健全多方参与制度、推进全民福利共享三项建议,针对我国国家公园体制建设提出了制定《国家公园法》、设置自然保护地顶层规划两项建议,以期促进三江源国家公园管理能力提升、推动我国国家公园体制建设。     

Lethal intergroup aggression by chimpanzees in Kibale National Park, Uganda

Chimpanzees (Pan troglodytes) have hostile intergroup relations throughout most or all of their geographic range. Hostilities include aggressive encounters between members of neighboring communities during foraging and during patrols in which members of one community search for neighbors near territory boundaries. Attacks on neighbors involve coalitions of adult males, and are sometimes fatal. Targets include members of all age/sex classes, but the risk of lethal intergroup coalitionary aggression is highest for adult males and infants, and lowest for sexually swollen females. The best-supported adaptive explanation for such behavior is that fission-fusion sociality allows opportunities for low-cost attacks that, when successful, enhance the food supply for members of the attackers' community, improve survivorship, and increase female fertility. We add to the database on intergroup coalitionary aggression in chimpanzees by describing three fatal attacks on adult males, plus a fourth attack on an adult male and an attack on a juvenile that were almost certainly fatal. Observers saw four of these attacks and inferred the fifth from forensic and behavioral evidence. The attackers were males in two habituated, unprovisioned communities (Ngogo and Kanyawara) in Kibale National Park, Uganda. We also summarize data on other intercommunity attacks at Ngogo. Our observations are consistent with the "imbalance of power" hypothesis [Manson & Wrangham, Current Anthropology 32:369-390, 1991] and support the argument that lethal coalitionary intergroup aggression by male chimpanzees is part of an evolved behavioral strategy.     

自然旅游地居民自然保护态度的影响因素——中国九寨沟和英国新森林国家公园的比较

居民的自然保护态度对自然旅游地的自然保护与旅游可持续发展至关重要,自然旅游地居民自然保护态度的影响因子及影响方式,已经成为自然旅游地管理的重要内容,但相关研究薄弱。以中国九寨沟和英国新森林国家公园(New Forest National Park,NF)为例,根据实地问卷调查数据,从两地居民的人口属性、旅游环保期望、旅游环境影响感知及旅游环境伦理观与其自然保护态度关系的角度,进行定量比较研究。研究发现:(1)两地居民的自然保护态度受不同因子的影响,存在明显的中外差异;(2)人口属性特征如性别、年龄、居住年限、教育水平及旅游业参与情况对新森林国家公园社区居民的自然保护态度没有影响;但性别、旅游业参与情况却影响九寨沟居民的自然保护态度,女性及旅游业参与者更支持对九寨沟进行自然保护;(3)新森林国家公园居民的自然保护态度受其旅游环保期望及旅游环境伦理观的影响:旅游环保期望较高、持保护主义环境伦理观的新森林国家公园居民,更有可能支持对新森林国家公园进行自然保护;(4)九寨沟居民的自然保护态度不受其旅游环保期望及旅游环境伦理的影响,但受其旅游环境影响感知的影响;居民的旅游环境影响感知越消极,越支持对九寨沟进行自然保护。     

Baobabs and elephants in Kruger National Park: nowhere to hide

Baobab size class distributions were surveyed in the Limpopo National Park (LNP), Mozambique, and the Kruger National Park (KNP), South Africa. There are very few elephants in the LNP and the baobab population there had a reverse J-shaped size class distribution with many small baobabs. In contrast, the elephant-impacted baobab population of KNP displayed a mono-modal size-class distribution, with a lack in recruitment. Within KNP, elephant impact (percentage bark stripped up to the height of 3 m) decreased with increasing rockiness and slope steepness. We interpret this to suggest that steep rocky slopes are inaccessible to elephants and therefore these sites may act as a refuge for baobabs. In such inaccessible areas, the baobab population has a similar size-class distribution to that of the populations in the LNP. However, these baobab refugia are restricted in the northern KNP landscape and are therefore probably not large enough to sustain a viable baobab population.     

Demographic and Female Life History Parameters of Free-Ranging Chimpanzees at the Chimpanzee Rehabilitation Project, River Gambia National Park

We analyzed fertility and mortality records for 113 provisioned, free-ranging chimpanzees at the River Gambia National Park, The Gambia. The chimpanzees are rehabilitated orphans released by the Chimpanzee Rehabilitation Project (CRP), and their descendants born in a natural environment. Females experienced their 1st births at an average age of 14.3 yr, with average interbirth intervals of 68 mo. Despite limited provisioning, reproductive parameters in both released and 1st-generation females resembled those of wild chimpanzees and showed seasonal fluctuations. Mortality rates were low compared to those for wild chimpanzees, particularly for infants and juveniles; life expectancy at birth was 23.6 yr for females and 18 yr for males. The results have implications for our understanding of variation in reproductive parameters between captive and wild chimpanzees. We also discuss issues related to chimpanzee conservation and captive rearing.     

瓦屋山国家森林公园蕨类植物区系分析

在野外调查和分类的基础上,对瓦屋山国家森林公园蕨类植物进行了初步的区系分析。现已知该地区共有蕨类植物36科,71属,156种,以热带成分为主,温带成分次之。蕨类植物的区系分析表明：(1)物种多样性丰富。科、属、种分别占四川的69．2％、55．5％和21．4％;(2)物种具有古老性和特有性。残遗植物以及中国,四川特有种多;(3)物种具有过渡性。