Ranging behavior of Mahale chimpanzees: a 16 year study (original) (raw)
Related papers
Behavioral Ecology, 2003
Group size is expected to be an important factor to predict home-range (HR) size in social animals. In chimpanzees adult males play an important role in defending the HR against neighbors, and therefore it has been suggested that HR size depends on the number of adult males. In this long-term study on wild West African chimpanzees, we analyzed the relative importance of community size and composition on ranging patterns over a 10-year period, using multivariate statistics. Because community size decreased from 51 individuals with 6 adult males in 1992 to 22 individuals with only 1 adult male in 2001, we expected a decrease in HR size, which should be better predicted by the number of males than by community size. We further investigated the effect of fruit availability on monthly HRs over a 4-year period. As predicted, HR size decreased during the first 7 years of our study but increased during the last 3 years. Overall, the number of adult males was the best predictor of HR size, whereas fruit availability did not correlate with HR size. HR use remained stable over the entire study period, with a constant proportion of about 35% of the HR used as core area. High HR and core-area overlap values between different years indicated strong site-fidelity. Although the number of males within the community explained the decrease in HR size, the recent increase in size remains unexplained. This finding suggests that other factors such as relative fighting power of males affect HR size.
Bisexually bonded ranging in chimpanzees (Pan troglodytes verus)
Behavioral Ecology and Sociobiology, 2005
Abstact While male mammals seek to maximize access to potential mates, females maximize feeding efficiency. Ranging patterns are therefore often sex specific. Sexspecific ranging patterns have also been reported for East African chimpanzees and a recent study on female ranging patterns concludes that social organization is best described by a male-bonded community model, where females occupy individual home ranges that are distributed within the boundaries of the male-defended range. In West African chimpanzees, however, such sexspecific ranging patterns have not been consistently observed and a bisexually bonded community model, where both sexes use the entire home range equally, has been suggested to best describe social organization. In this study we analyze 5 years of data on individual ranging patterns of chimpanzees in the Taï National Park (Côte d'Ivoire) to test specific predictions of the different models of chimpanzee social organization. We found that although males in Taï had slightly larger home ranges than females, all individual home ranges and core areas overlapped highly. Small individual home range size differences were entirely due to the use of peripheral areas and were correlated with female social dominance. These findings strongly support the bisexually bonded community model for Taï chimpanzees. Thus, we conclude that there are fundamental differences in the spaceuse patterns of East and West African chimpanzees and discuss possible factors leading to such differences.
Male core areas: ranging by Budongo Forest chimpanzees
Pan Africa News, 2000
Male chimpanzees are generally considered to make fairly even use of their home range, while in contrast, females show more restricted ranging patterns, spending much of their time in small fragments (core areas) of the community's home range. Restricted ranging of (non-cycling) females may relate to either ensuring access to good food resources, or reducing the risk of inter-community infanticide, while males may range widely to search for potential mates and contest inter-community territorial borders. Careful reading of published accounts suggests, however, that sex differences in ranging patterns may not be so extreme. In the Gombe National Park, Tanzania, where females have readily identifiable core areas, males are also described as having core areas, and in the Kibale National Park, Uganda, males as well as females showed a 'clumped' pattern of range use. Detailed analysis of the ranging patterns of male chimpanzees in the Budongo Forest, Uganda, provides further support for this view.
Ranging patterns of chimpanzees in a montane forest of Kahuzi, Democratic Republic of Congo
International journal of primatology, 2005
I studied ranging patterns of a semihabituated unit-group of chimpanzees for 60 mo at Kahuzi. They had a total home range of 12.81 km 2 and a mean annual home range of 7.55 km 2. Considering the low density of chimpanzees in the area vis-à-vis chimpanzees in arid areas, their home range is very small. Kahuzi chimpanzees used the home range in a clumped pattern, frequently visiting the core area and only rarely entering peripheral areas. The monthly range changes with fruit availability, increasing during periods of fruit scarcity. There was no consistent seasonal difference in the size of the home range. However, use of different habitat types may vary seasonally. While there was no seasonal effect in the use of primary forest, the chimpanzees showed a statistically consistent seasonal difference in their use of secondary forest, visiting it mainly during the dry season when fig trees were in fruit. Since the primary forest provides them with more food fruits, chimpanzees tended to use more frequently the small patches of primary forest in their home range. Thus, the size and distribution of small fragmented primary forests may be an important factor influencing the ranging pattern of chimpanzees at Kahuzi.
We contrast the range use patterns of male and female chimpanzees (Pan troglodytes) based on repeated sightings over three years of 19 individuals in the Kanyawara community of Kibale Forest Reserve, Uganda. Depending on how home range size was calculated, male chimpanzees used an area that was 1.5 to 2 times greater than that of females. There was no difference between the sexes in whether their home ranges were used in a clumped or uniform fashion. However, males were more likely to be seen in boundary areas than females. These results are discussed in light of previously proposed models of chimpanzee social organization. It is concluded that the scenario in which females have smaller core areas within the defended home range of the males is most strongly supported by the range use patterns observed in Kibale chimpanzees. 1993 WiIey-Liss, Inc.
Locomotor behavior and long bone morphology in individual free-ranging chimpanzees
Journal of human …, 2006
We combine structural limb data and behavioral data for free-ranging chimpanzees from Ta€ ı (Ivory Coast) and Mahale National Parks (Tanzania) to begin to consider the relationship between individual variation in locomotor activity and morphology. Femoral and humeral cross sections of ten individuals were acquired via computed tomography. Locomotor profiles of seven individuals were constructed from 3387 instantaneous time-point observations (87.4 hours). Within the limited number of suitable chimpanzees, individual variation in locomotor profiles displayed neither clear nor consistent trends with diaphyseal cross-sectional shapes. The percentages of specific locomotor modes did not relate well to diaphyseal shapes since neither infrequent nor frequent locomotor modes varied consistently with shapes. The percentage of arboreal locomotion, rather than estimated body mass, apparently had comparatively greater biological relevance to variation in diaphyseal shape. The mechanical consequences of locomotor modes on femoral and humeral diaphyseal shapes (e.g., orientation of bending strains) may overlap between naturalistic modes more than currently is recognized. Alternatively, diaphyseal shape may be unresponsive to mechanical demands of these specific locomotor modes. More data are needed in order to discern between these possibilities. Increasing the sample to include additional free-ranging chimpanzees, or primates in general, as well as devoting more attention to the mechanics of a greater variety of naturalistic locomotor modes would be fruitful to understanding the behavioral basis of diaphyseal shapes.
Primates, 2009
Each local population of chimpanzees shows cultural variation, but little is known about how behavioral variations first emerge, and how often variants spread to other individuals and then become fixed as a local culture in chimpanzee society. Although field studies of chimpanzees are still too short to answer these questions definitively, it may stimulate further study in various sites to summarize the developments observed over the past 40 years at Mahale, Tanzania. Innovative patterns were operationally defined as new behavioral patterns performed by M group chimpanzees from 1981 onwards. Innovations included patterns of feeding (n = 8), human-directed behavior (n = 3), hygiene behavior (n = 4), maternal carrying of infants (n = 2), courtship (n = 2), play (n = 6), intimidation displays (n = 3), and quasi-grooming (n = 4). Although most patterns were repeated later by other individuals, six patterns were never seen performed by another individual, and eight patterns were performed by one or a few individuals but social transmission was unlikely. Thus, innovation was not rare, but emergence of fashion or establishment of traditions seems to occur rarely in chimpanzee society.
Environmental variability supports chimpanzee behavioural diversity
Nature Communications
Large brains and behavioural innovation are positively correlated, species-specific traits, associated with the behavioural flexibility animals need for adapting to seasonal and unpredictable habitats. Similar ecological challenges would have been important drivers throughout human evolution. However, studies examining the influence of environmental variability on within-species behavioural diversity are lacking despite the critical assumption that population diversification precedes genetic divergence and speciation. Here, using a dataset of 144 wild chimpanzee (Pan troglodytes) communities, we show that chimpanzees exhibit greater behavioural diversity in environments with more variability — in both recent and historical timescales. Notably, distance from Pleistocene forest refugia is associated with the presence of a larger number of behavioural traits, including both tool and non-tool use behaviours. Since more than half of the behaviours investigated are also likely to be cultu...
Navigating in a Rainforest: Movement Patterns in a Neotropical Primate. The Black Howler Monkey
2020
and Alex Carlin. Especially to Elsa Barrios, whose dedication was remarkable. Undoubtedly, without you this work would have never taken place. I could not be more thankful to Prof. Alejandro Estrada and Dr. Sarie Van Belle who introduced me to the fascinating world of Palenque and gave me the opportunity of being part of their team. Your hard work, courage and passion for science and for protecting primates was really inspirational for me. I would like to thank Dr. Karline Janmaat for "adopting" me as part of her research group and helping me to build up the logic of my research questions but also to support me during complicated times. I would like to thank Dr. Roger Mundry for constantly pushing the boundaries of my reasoning and helping me reconstructing my thoughts and ideas. I am enormously thankful to all the colleagues at the Max Plank Institute for Evolutionary Anthropology that contributed to this thesis with their discussions, comments and highly useful feedback. I am immensely thankful to Prof. Anna Nekaris and Prof. Vincent Nijman, who welcomed me with open arms and were always willing to share their knowledge, ideas and advice. Thank you, Anna, for introducing me to the world of teaching, for constantly providing positive and constructive criticism and for your enormous scientific creativity. My experience at Oxford Brookes University would not have been the same without the wonderful people that accompanied me along the way, whose vii inspirational work on conservation and science is only equalled by the enormous value of their kindness. This journey took me to meet professionals that I greatly admire and now I am proud to consider them as my colleagues and friends. It has been a period of professional and personal growth thanks to all the people that shared part of their lives with this project. I am sure we will keep on navigating together through the paths of science in the future. I am especially grateful to Rocío Rodríguez, who took the time and effort to contribute with her wonderful art to the cover of this thesis. Finally, I would like to mention how grateful I am to the Mexican people, their culture and heritage, especially in Palenque, for welcoming a foreigner to study their wonderful living primates. Palenque, its people and its nature will remain in the deepest part of my heart and mind forever. This thesis is dedicated to my parents, Carlos and Carmen, who consistently supported me along this exciting adventure.