Retardation of sexual maturation of free-ranging Japanese macaques induced by controlled provisioning

供应支持Koshima日本猕猴种群的高密度。从1972年秋至1977年6月，所提供的粮食数量受到严格限制。这导致了人口下降阶段。1977年以后，大豆在夏季供应1个半月，使人口增长进入稳定阶段。在这些条件下研究了男性性成熟，我们在“男性成熟与脱离母体”、“从小的双性恋群体转变为具有男性群体特征的群体”的框架下研究了两个主题。体重随年龄的增长曲线使用1972年的横断面数据，当时食物供应不受限制。20世纪70年代，每只猴子的体重增长缓慢，一直持续到15岁。研究人员发现，15岁以后的孩子有两组，一组体重在10公斤左右，另一组8公斤左右。8岁后生长曲线变化较大，可能与性成熟有关。每个男性在供应区域的出席表明，男性在青春期抛弃了主要群体，并加入了小分支群体，或所有男性聚会。然后他们在15岁后回到主要群体，参加生育活动。低体重雄鼠在8岁左右离开主群，回归主群的时间晚于体重较重雄鼠。遗弃的年龄变化很大，在6-8岁时达到高峰，体重在5kg左右。后来的叛逃者体重更重，这表明这些男性受到社会因素的影响。小分支群体接受了年轻的逃兵，这影响了这个双性恋群体的特征，变得更像一个男性群体。与主要小组相比，小组成员表现出松散的联系。与正常情况不同的是，群体运动很少通过“coo”的声音来协调，甚至雌性也经常摇晃树，这在雄性群体中很常见。由于蚁群的移动范围较小，个体只会访问少量的觅食树，并且会反复访问同一棵树。成员们在树上会合，成年雄性容忍雌性与它们一起进食。当其他成员在不同的区域活动时，年长的青春期雄性会去觅食树。当它们在树上遇到雌性时，它们会因为雌性的叫声而把它们赶走或从树上撤退。少壮期雄虫等待占领的成年雌虫离开觅食树。在交配季节到来之前，外生雄虫和青春期雄虫在雌虫数量较少的取食树上等待雌虫，这对雌虫的取食活动有很大的影响

Provisioning support the high density of the Koshima population of Japanese macaques. The amount of provisioned food was severely restricted from the autumn of 1972 until June, 1977. This caused a population declining phase. Soy beans were provisioned for 1 and half months in the summer after 1977, which caused a stable phase of population growth. Male sexual maturation has been studied under these conditions, and we studied two topics under the framework, "Male maturation and desertion from the natal troop", "Transformation of a small bisexual group into a group having the characteristics of a male group".The body weight growth curve against age is depicted using cross sectional data of 1972 when provisioning food was not restricted. Body weight growth of each monkey in the 1970's was slowed down, and growth continued until age 15. Two groups were found, one which was around 10kg and the other 8kg body weight after age 15. Large variation in growth curves was observed after 8 years ol … More d, which may be related to sexual maturation. Attendance of each male at the provisioning area revealed that males deserted the main group at adolescence, and joined the small branch group, or the all male gatherings. Then they came back to the main group after reaching 15 years of age, participating in reproductive activity. The low body weight males deserted the main group at around 8 years, and came back to the main group later than the heavier males. The age of desertion varied much, having a peak at 6-8 years, and a body weight of around 5kg. Later desertors were heavier, indicating social factors for these males.The small branch group accepted young deserter males, which influenced the characteristics of this bisexual group becoming more like a male group. The group members showed loose association as compared to the main group. Unlike the normal situation, group movement was rarely coordinated by "coo" sound, and even females showed frequent tree-shaking which is common in a male group. As the moving range of the group was small, individuals visited only a small number of feeding trees, and visited the same trees repeatedly. Members joined at the trees, and adult males tolerated females feeding with them. Senior adolescent males visited the feeding trees while other members were moving in a different area. When they met females at the trees, they chased them away or retreated from the trees because of the cries of females. The junior adolescent males waited for the occupying adult females to leave the feeding trees before. Just prior to the mating season, outside males and adolescent males waited for females at their small number of feeding trees, which had a strong affect on the feeding activities of females Less