Field Study of Mammalian Behavioral Development

霍勒坎普博士和她的同事们正在继续他们对斑点鬣狗行为发育的实地研究。斑点鬣狗生活在复杂的、类似灵长类动物的社会中，被称为“氏族”，有5到100名成员。虽然雌性鬣狗终生留在他们的出生地部落，但所有年轻的雄性最终都会移民。每一个鬣狗氏族都是由一个严格的、线性的支配等级结构组成的，也就是“权势等级”。斑点鬣狗与大多数其他哺乳动物的不同之处在于，在成年动物中，雌性在社交上比雄性占优势。一种动物加入侵略者对抗第三个个体的联盟经常发生，这可能在鬣狗社会中等级关系的发展和维持中发挥重要作用。这一阶段的研究有三个目标：(1)记录联盟行为的发展、原因和后果；(2)确定男性为什么从他们出生的氏族移民，他们如何融入新的社会群体，以及分散如何影响他们的社会等级；(3)阐明研究群体中的交配系统。研究中的80只鬣狗组成了肯尼亚马赛马拉国家保护区的一个大家族。每个氏族成员的年龄、社会史和亲属关系都是从以前的研究中得知的。研究人员正在使用无线电跟踪、行为观察和亲子关系的分子遗传学分析。这项研究将有助于阐明(1)哺乳动物扩散行为的原因和后果，(2)社会优势的发展和维持，以及(3)大型食肉动物的社会生物学。

Dr. Holekamp and her colleagues are continuing their field study of behavioral development in the spotted hyena. Spotted hyenas live in complex, primate-like societies, called "clans," with 5 to 100 members. Whereas female hyenas remain in their natal clans for life, all young males eventually emigrate. Each hyena clan is structured by a rigid, linear dominance hierarchy, or "pecking order." Spotted hyenas differ from most other mammals in that females are socially dominant to males among adults. Coalitions in which one animal joins an aggressor against a third individual occur frequently and may function importantly in the development and maintenance of rank relations in hyena societies. This phase of the research has three goals: (1) to document the development, causes, and consequences of coalitionary behavior; (2) to determine why males emigrate from their natal clans, how they become integrated into their new social groups, and how dispersal influences their social rank; (3) to elucidate the mating system in the study population. The 80 hyenas being studied comprise one large clan in the Masai Mara National Reserve, Kenya. The age, social history, and kin relations of each clan member are known from previous study. The researchers are using radio tracking, behavioral observation, and molecular-genetic analysis of paternity. The research will help elucidate (1) the causes and consequences of mammalian dispersal behavior, (2) the development and maintenance of social dominance, and (3) the social biology of large carnivores.