@article{oai:ir.soken.ac.jp:00003824,
 author = {長谷川, 眞理子 and HASEGAWA, Toshikazu and HIRAI-HASEGAWA, Mariko},
 issue = {1-2},
 journal = {Journal of Ethology, Journal of Ethology},
 month = {Nov},
 note = {The mating patterns of free-ranging chimpanzees (Pan troglodytes) of the Mahale Mountains, Tanzania, were studied. Opportunistic mating (non-competitive and temporary mating) was frequently observed in a large-sized unit-group, among young, low-ranking males, and among young, newcomer, non-ovulating females. Restrictive mating (a continuous sexual relationship between a particular pair which includes possessiveness and consortship) was frequently observed in a small-sized unit-group, among middle- and old-aged, high-ranking males, and among old, resident, ovulating females. Relations between those characteristics, such as group size and composition, ages of the individuals of both sexes, female estrous stages, and life history, and the 2 mating patterns are discussed.},
 pages = {75--85},
 title = {Opportunistic and restrictive matings among wild chimpanzees in the Mahale Mountains, Tanzania},
 volume = {1},
 year = {1983}
}