A model of the gelada socio-ecological system

Data from three populations of gelada baboons are used to generate a model of the species' socio-ecology that relates time budget requirements to group size, day journey length, and relevant environmental parameters. The model is used to examine the range of environmental conditions under which gelada could survive. This analysis indicates that a grazing primate like the gelada would run out of available time for foraging at just above and just below the altitudes at which they are now found. This suggests that, contrary to previous supposition, gelada were not driven into a retreat habitat by more competitivePapio baboons, but rather withdrew from lower altitude habitats because they could not survive under these conditions as the climate deteriorated during the Holocene.

[1]  H. Ikeda.  Population changes and ranging behaviour of wild Japanese monkeys at Mt. Kawaradake in Kyushu, Japan , 1982, Primates.

[2]  P. Waser.  7 – Feeding, Ranging and Group Size in the Mangabey Cercocebus albigena , 1977 .

[3]  Jan R. De Ruiter,et al.  The Influence of Group Size On Predator Scanning and Foraging Behaviour of Wedgecapped Capuchin Monkeys (Cebus Olivaceus) , 1986 .

[4]  Robin I. M. Dunbar,et al.  Maternal time budgets of gelada baboons , 1988, Animal Behaviour.

[5]  A. Mori,et al.  The distribution of baboon species and a new population of gelada baboons along the Wabi-Shebeli river, Ethiopia , 1990, Primates.

[6]  Robin I. M. Dunbar,et al.  Social dynamics of gelada baboons. , 1975, Contributions to primatology.

[7]  R. Wrangham,et al.  Ecological and Sociological Studies of Gelada Baboons , 1980 .

[8]  Robin I. M. Dunbar.  Reproductive Decisions: An Economic Analysis of Gelada Baboon Social Strategies , 1984 .

[9]  N. Tappen.  Problems of Distribution and Adaptation of the African Monkeys , 1960, Current Anthropology.

[10]  D. H. Bell,et al.  Chapter 1 – Photosynthesis, Plant Productivity, and Crop Yield , 1980 .

[11]  A. Mckay.  Seasonal and management effects on the composition and availability of herbage, steer diet and live-weight gains in a Themeda triandra grassland in Kenya. II. Results of herbage studies, diet selected and live-weight gains , 1971, The Journal of Agricultural Science.

[12]  Robin I. M. Dunbar,et al.  Ecological relations and niche separation between sympatric terrestrial primates in Ethiopia. , 1974, Folia primatologica; international journal of primatology.

[13]  Robin I. M. Dunbar.  9 – Feeding Ecology of Gelada Baboons: a Preliminary Report , 1977 .

[14]  Robin I. M. Dunbar,et al.  Time: a hidden constraint on the behavioural ecology of baboons , 1992, Behavioral Ecology and Sociobiology.

[15]  F. T. Jung.  The Fire of Life , 1962 .

[16]  Robin I. M. Dunbar.  Primate social systems , 1987 .

[17]  E. Delson,et al.  Evolutionary history of the primates , 1979 .

[18]  R. Quris.  Ecologie et organisation sociale de Cercocebus galeritus agilis dans le Nord-Est du Gabon , 1975, La Terre et La Vie, Revue d'Histoire naturelle.

[19]  Wrangham Rw,et al.  Sex differences in the behavioural ecology of chimpanzees in the Gombe National Park, Tanzania. , 1980 .

[20]  A. Sinclair,et al.  The African Buffalo: A Study of Resource Limitation of Populations , 1978 .

[21]  Robin I. M. Dunbar.  Energetics, thermoregulation and the behavioural ecology of klipspringer , 1979 .

[22]  Dunbar Rim.,et al.  Thermoregulation, habitat quality and the behavioural ecology of gelada baboons ( Theropithecus gelada). , 1983 .

[23]  M. Parry.  Secular climatic change and marginal agriculture , 1975 .

[24]  R. J. Boer,et al.  The effect of group size on time budgets and social behaviour in wild long-tailed macaques (Macaca fascicularis) , 1983, Behavioral Ecology and Sociobiology.

[25]  L. Tieszen,et al.  Seasonal changes in the nutrient content of East African grassland vegetation , 1988 .

[26]  I. Deshmukh.  A common relationship between precipitation and grassland peak biomass for East and southern Africa , 1984 .

[27]  M. Coe,et al.  Biomass and production of large African herbivores in relation to rainfall and primary production , 1976, Oecologia.

[28]  Herbert H. T. Prins,et al.  A balanced diet as a goal for grazing: the food of the Manyara buffalo , 1989 .

[29]  P. Stacey,et al.  Group size and foraging efficiency in yellow baboons , 2004, Behavioral Ecology and Sociobiology.

[30]  P. V. Soest.  Nutritional Ecology of the Ruminant , 1994 .

[31]  W. E. Le Gros Clark,et al.  History of the primates , 1950 .

[32]  Robin I. M. Dunbar,et al.  Observations on baboons, Papio anubis, in an arid region in Ethiopia. , 1971, Folia primatologica; international journal of primatology.

[33]  Robin I. M. Dunbar.  DEMOGRAPHIC AND LIFE HISTORY VARIABLES OF A POPULATION OF GELADA BABOONS (THEROPITHECUS GELADA) , 1980 .

[34]  S. Altmann,et al.  Nutrients and toxins of plants in Amboseli, Kenya , 1987 .

[35]  C. Hoste,et al.  Rangeland production and annual rainfall relations in the Mediterranean Basin and in the African Sahelo Sudanian zone. , 1977 .

[36]  Robin I. M. Dunbar,et al.  Social organization of gelada baboons: Social units and definitions , 2006, Primates.

[37]  Montague W. Demment,et al.  A Nutritional Explanation for Body-Size Patterns of Ruminant and Nonruminant Herbivores , 1985, The American Naturalist.

[38]  Robin I. M. Dunbar.  Functional significance of social grooming in primates , 1991 .

[39]  Robin I. M. Dunbar,et al.  On hybridization between Theropithecus gelada and Papio anubis in the wild , 1974 .

[40]  I. Deshmukh.  [Distribution and accumulation characteristics of nutrients in solar greenhouse soil in Ji'nan, Shandong Province of East China]. , 1986 .

[41]  Robin I. M. Dunbar,et al.  Variations in the demographic structure and dynamics of gelada baboon populations , 1984, Behavioral Ecology and Sociobiology.

[42]  Robin I. M. Dunbar,et al.  Adaptation to grass-eating in gelada baboons , 2006, Primates.

[43]  Robin I. M. Dunbar,et al.  Observer bias in selection of study group in baboon field studies , 1982, Primates.

[44]  Ecological modelling in an evolutionary context. , 1989, Folia primatologica; international journal of primatology.

[45]  C. Anderson.  Subtrooping in a chacma baboon (Papio ursinus) population , 1981, Primates.

[46]  T. Struhsaker.  Ecology of Vervet Monkeys (Cercopithecus Aethiops) in The Masai‐Amboseli Game Reserve, Kenya , 1967 .