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The louse egg-handling technique of a free-ranging troop of Japanese macaques were monitored to investigate the social diffusion of skills. The skills in the troop were distributed based on maternal lineages. The alteration of the louse egg-handling technique of one female from a one-hair combing technique to a forefinger loosening technique was later adopted by other female kin although the acquisition of the different elements of the technique showed temporal variation. The implications of these findings are discussed.

Grooming behavior of which the primary function appears to be the removal of lice on others (Tanaka and Takefushi [1993] Anthropological Science 101:187-193) was studied in Japanese macaques at Jigokudani Monkey Park, Japan, June 1990-July 1993. Several louse egg-handling techniques used during grooming were identified (with differences in efficiency) in a free-ranging group. In the low-ranking maternal lineages, the distribution of these techniques is quite homogeneous, suggesting social transmission with goal emulation (one form of social learning) based on maternal kin. However, there is considerable variation in the high-ranking matriline. The social system of dominance - the tendency of subordinates to groom more often than to be groomed - may result in oblique transmission of more effective techniques from low-ranking monkeys to some offspring of high-ranking females. KEY WORDS Social transmission, Dominance, Japanese Macaques

Tool-using behavior in Japanese macaques that involved the use of stones to obtain fruit from a pipe were studied at Jigokudani Monkey Park, Japan. A female threw a stone into the pipe to get the apple and this technique was subsequently used by a male and two other females. The females chose a stone of a particular weight for throwing and were able to vary the momentum of throwing stones to prevent other macaques from stealing the fruit.

A symbiotic bacterium of the macaque louse, Pedicinus obtusus, is characterized. The symbiont constituted a gammaproteobacterial lineage distinct from the symbionts of anthropoid primate lice and the designation 'Candidatus Puchtella pedicinophila' is proposed.