Recognition of conspecifics across auditory and visual modalities was studied in a female chimpanzee, using the auditory-visual matching-to-sample task (AVMTS). Following the presentation of a recorded sound, the subject had to select, from 2 alternatives, the photograph that was associated with the sample sound. In the present study, the chimpanzee who had acquired AVMTS in a previous experiment was shown novel stimuli of chimpanzees and birds, neither of which the subject had experienced before as stimuli. In the first session of the test, the subject generalized AVMTS performance to matching recorded chimpanzee vocalizations with the photographs, but not to matching bird songs with the relevant photographs. This might reflect auditory-visual intermodal recognition of conspecifics in the everyday life of the chimpanzee.

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Inverstigation of Wild Japanese Macaque group behavior in Kamikochi, Japan Alps. This confirmes that Traveling distance per day was clear seasonal change. The resultis that there is a peak Travering distnce per day between August to October, Spring follow this, and the minimum lies between january and February. The correlution was observed between Traveling distnce per day and Homerange size. and Japanese Macaque group travering was checked by intermittent snowfall in daytime. The strongest relation was observed in snowy season between daytime an avarage temprature and traveling distance.

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One goal of environmental enrichment in zoo is to make the behavioral repertoires and the activity budgets of captive animals as close to those of wild animals as possible. This study first described the behavioral patterns of 5 chimpanzees reared at the Maruyama Zoo, Sapporo, Japan. The observation was taken place in 1996 using focal animal sampling method. This result elucidated that zoo chimpanzees exhibited extremely different behavioral patterns compared with wild counterparts. Especially the duration of feeding behavior was much less. Therefore, this study further attempted to increase the duration of feeding by the control of the frequency of feeding provision during a day. This experiment showed that, even though total volume of food was equal, multi-frequency feeding is more effective for the prolongation of feeding time than single operation.

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Determination of peripheral lymphocyte subset levels becomes important method for analyzing immune function in nonhuman primates. However, It has been well-known that the separation of peripheral lymphocytes by density gradient centrifuge is relatively difficult in nonhuman primates, because the gravity of red blood cells (RBC) varies among individuals. The purpose of this paper is to compare the major lymphocyte subset levels, the recovery rate of lymphocyte and the contamination of RBC in lymphocyte fraction among four different methods of lymphocyte separation, Method-1: conventional density gradient centrifuge using Ficoll, Method-2: density gradient centrifuge after sedimentation of RBC using 5% dextran, Method-3: whole blood method A; hemolysis before staining lymphocyte, and Method-4: whole blood method B; hemolysis after staining lymphocytes. The lymphocyte recovery rate as well as RBC contamination were also compared between two different hemolysis methods, 1) hemolysis with distilled water and 2) hemolysis with NH₄Cl solution. The results obtained are as follows.
I. There was no difference in lymphocyte subset levels between Method-1 and Method-3, indicating that loss of specific lymphocyte subset(s) did not occur during density gradient centrifuge in method-1. The density gradient centrifugal method using Ficoll (d=1.077) was able to seem to adapt for rhesus monkeys.
II. CD16-positive lymphocytes could not be detected by method-4. It might be necessary to wash cells to remove IgG in sample before staining with anti-CD16, Leu-11a monoclonal antibody in the case of applying Method-4 to analyzing CD16-positive NK cells.
III. Method-2 was effective to remove RBC from lymphocyte fraction, but the lymphocyte recovery rate was significantly lower as compared to Method-1.
VI. The lymphocyte recovery rate was significantly higher when contaminated RBC were removed by NH₄Cl solution as compared when RBC were removed by distilled water.

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