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Behavioral Assessment of Manual Dexterity in Non-Human Primates
Published on: November 11, 2011
Ranging behavior of Mahale chimpanzees: a 16 year study
Michio Nakamura1, Nadia Corp, Mariko Fujimoto
1Wildlife Research Center, Kyoto University, 2-24, Tanaka-Sekiden-cho, Sakyo, Kyoto 606-8203, Japan. nakamura@wrc.kyoto-u.ac.jp
Primates; Journal of Primatology
|December 15, 2012
Summary
Chimpanzees (M group) in Tanzania primarily utilized a small portion of their extensive home range, with usage shifting seasonally and over time. Home range size correlated with female numbers, challenging male-defended territory models.
Area of Science:
- Primatology
- Behavioral Ecology
- Conservation Biology
Background:
- Understanding chimpanzee ranging patterns is crucial for their conservation.
- Previous models suggested male-defended territories in East African chimpanzees.
- The Mimikire group (M group) in Mahale Mountains National Park provides a unique study population.
Purpose of the Study:
- To analyze the ranging patterns of the Mimikire group of chimpanzees over 16 years.
- To investigate factors influencing home-range size and usage.
- To test predictions of the male-defended territory model.
Main Methods:
- Analysis of chimpanzee movement data over a 16-year period.
- Estimation of home-range size using grid-cell and minimum convex polygon (MCP) methods.
- Correlation analysis between home-range size and demographic factors (adult males and females).
Main Results:
- The M group utilized approximately 70% of their total home range annually, with 80% covered within 5 years and 95% within 11 years.
- Chimpanzees concentrated over half their time in only 15% of their home range, indicating focused resource use.
- Monthly range size varied seasonally, being smallest in the rainy season and largest in the dry season.
- Range overlap between years was low in June but high during the fruit abundance season (August-January).
- A shift in range use was observed, with decreased use of the northern area and increased use of the eastern mountainous region.
- Home-range size positively correlated with the number of adult females, but not adult males.
Conclusions:
- Chimpanzees exhibit significant spatial and temporal variation in home-range use, concentrating activity in core areas.
- The findings do not support the male-defended territory model for this chimpanzee group.
- The number of adult females appears to be a more significant factor in determining home-range size than the number of adult males.
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