Little is known about the social behavior of pygmy slow lorises, in particular, the social relationships of same‐sex individuals have rarely been investigated. The Slow Loris Conservation Center was built at the Japan Monkey Center to enhance the welfare of confiscated slow lorises, promote their conservation, improve public education, and perform scientific research on the species. In the course of improving housing conditions, several same‐sex pairs of pygmy slow lorises were formed. We monitored their behaviors and fecal glucocorticoid metabolite (FGM) levels to understand whether male same‐sex pairings could be a feasible management strategy. The subjects were 10 male and 6 female lorises for comparison, all of whom were over 5 years old. We successfully formed five pairs of male lorises after eight formation attempts. Male pairs initially showed some aggressive behaviors; however, the rate decreased approximately 10 days after introduction. All of the male pairs eventually exhibited extensive affiliative social behaviors, including allogrooming and social play, during the dark (active) phase, and sleep site sharing during the light (inactive) phase. The rate of sleep site sharing during the light phase was higher than expected, suggesting that the pairs preferred to stay near each other. There was no evidence of increased stress after a long period of male–male social housing. Female same‐sex pairs and male–female pairs demonstrated a high level of affiliative behaviors right after the introduction. These results highlight the flexibility and high sociability of this species and indicate that such same‐sex pairings are a feasible option for their social management.

中文翻译：

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圈养的雄性侏儒慢虱（Nycticebus pygmaeus）之间的社会关系：形成雄性同性对是否是可行的管理策略？

侏儒慢虱的社会行为知之甚少，特别是，很少研究同性个体的社会关系。慢懒猴保护中心建于日本猴子中心，目的是增强没收的慢虱的福利，促进其保护，改善公众教育并对该物种进行科学研究。在改善住房条件的过程中，形成了几对同性的侏儒慢虱。我们监测了他们的行为和粪便糖皮质激素代谢物（FGM）的水平，以了解男性同性配对是否可能是可行的管理策略。供比较的对象是10头雄性和6头雌性，均为5岁以上。经过八次尝试，我们成功地形成了五对雄性懒猴。雄对最初表现出一些侵略性行为。但是，导入后约10天，发病率下降了。最终，所有男性对都表现出广泛的从属社交行为，包括在黑暗（活跃）阶段的配饰和社交活动，在明亮（不活跃）阶段的睡眠部位共享。轻度阶段的睡眠部位共享率高于预期，表明这对夫妻更喜欢彼此靠近。长期的男女住房后，没有证据表明压力增加。引进后，女性同性对和男性-女性对表现出较高的联结行为。