title: Ranging behavior of Mahale chimpanzees: a 16 year study.
abstract: We have analyzed the ranging patterns of the Mimikire group (M group) of chimpanzees in the Mahale Mountains National Park, Tanzania. During 16 years, the chimpanzees moved over a total area of 25.2 or 27.4 km(2), as estimated by the grid-cell or minimum convex polygon (MCP) methods, respectively. Annually, the M group used an average of 18.4 km(2), or approximately 70 %, of the total home-range area. The chimpanzees had used 80 % of their total home range after 5 years and 95 % after 11 years. M group chimpanzees were observed more than half of the time in areas that composed only 15 % of their total home range. Thus, they typically moved over limited areas, visiting other parts of their range only occasionally. On average, the chimpanzees used 7.6 km(2) (in MCP) per month. Mean monthly range size was smallest at the end of the rainy season and largest at the end of the dry season, but there was much variability from year to year. The chimpanzees used many of the same areas every year when Saba comorensis fruits were abundant between August and January. In contrast, the chimpanzees used several different areas of their range in June. Here range overlap between years was relatively small. Over the 16 years of the study we found that the M group reduced their use of the northern part of their range and increased their frequency of visits to the eastern mountainous side of their home range. Changes in home-range size correlated positively with the number of adult females but not with the number of adult males. This finding does not support a prediction of the male-defended territory model proposed for some East African chimpanzee unit-groups.
authors.affiliation: Wildlife Research Center, Kyoto University, 2-24, Tanaka-Sekiden-cho, Sakyo, Kyoto 606-8203, Japan. nakamura@wrc.kyoto-u.ac.jp
authors.forename: Michio
authors.initials: M
authors.lastname: Nakamura
authors.forename: Nadia
authors.initials: N
authors.lastname: Corp
authors.forename: Mariko
authors.initials: M
authors.lastname: Fujimoto
authors.forename: Shiho
authors.initials: S
authors.lastname: Fujita
authors.forename: Shunkichi
authors.initials: S
authors.lastname: Hanamura
authors.forename: Hitoshige
authors.initials: H
authors.lastname: Hayaki
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Hosaka
authors.forename: Michael A
authors.initials: MA
authors.lastname: Huffman
authors.forename: Agumi
authors.initials: A
authors.lastname: Inaba
authors.forename: Eiji
authors.initials: E
authors.lastname: Inoue
authors.forename: Noriko
authors.initials: N
authors.lastname: Itoh
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Kutsukake
authors.forename: Mieko
authors.initials: M
authors.lastname: Kiyono-Fuse
authors.forename: Takanori
authors.initials: T
authors.lastname: Kooriyama
authors.forename: Linda F
authors.initials: LF
authors.lastname: Marchant
authors.forename: Akiko
authors.initials: A
authors.lastname: Matsumoto-Oda
authors.forename: Takahisa
authors.initials: T
authors.lastname: Matsusaka
authors.forename: William C
authors.initials: WC
authors.lastname: McGrew
authors.forename: John C
authors.initials: JC
authors.lastname: Mitani
authors.forename: Hitonaru
authors.initials: H
authors.lastname: Nishie
authors.forename: Koshi
authors.initials: K
authors.lastname: Norikoshi
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Sakamaki
authors.forename: Masaki
authors.initials: M
authors.lastname: Shimada
authors.forename: Linda A
authors.initials: LA
authors.lastname: Turner
authors.forename: James V
authors.initials: JV
authors.lastname: Wakibara
authors.forename: Koichiro
authors.initials: K
authors.lastname: Zamma
mesh_terms: D000818:Animals; D003710:Demography; D005260:Female; D006702:Homing Behavior; D008297:Male; D002679:Pan troglodytes / Q000502:physiology*; D012621:Seasons; D013636:Tanzania