Demographic Change and Reproductive Skew in Cooperative Breeding Primates (resubmit)

合作育种灵长类动物的人口统计变化和生殖偏差（重新提交）

• 批准号: 0216096
• 负责人: James Dietz
• 金额: $ 21.8万
• 依托单位: University of Maryland, College Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-07-15 至 2006-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0216096&HistoricalAwards=false
• 关键词: Demographic; Change; Reproductive; Skew; Cooperative

Although rare relative to other social systems, cooperative breeding species present unique opportunities to examine hypotheses explaining the evolution of cooperation and competition in kin-based societies. Early studies focused on the adaptive significance of alloparental care. Specifically, why did mature adults remain in their natal groups helping to raise offspring not their own? For various species of birds and a few mammals, substantial progress has been made in addressing the original question of why helpers help. By staying at home, alloparents often improve their chances of finding a breeding opportunity and receive gains in indirect fitness. Early research on callitrichid primates (marmosets, tamarins and lion tamarins) in captivity suggested that social and genetic monogamy was the norm for the family but recent reports from the wild and in captive settings suggested that callitrichid social organization is highly flexible, both within populations and across taxa. This variability provides fertile ground for testing hypotheses concerning the basis of reproductive skew and delayed dispersal. Dietz, Baker and colleagues propose a 3-year continuation of behavioral and demographic research on golden lion tamarin monkeys in Poco das Antas Reserve, Brazil. This 17-year study is unique in terms of its ability to address questions at the population level and in its scope, maintaining an integrated set of databases including behavior, demography, kinship, morphology, reproduction, use of space, group dynamics, food habits and samples of blood, hair and feces. During the first 13 years of this research, lion tamarin territories occupied all suitable habitat in the reserve, most groups contained several helpers and population growth was limited by high mortality during dispersal from natal groups. In the past three years a novel form of predation, decimation of complete groups while in den sites, resulted in profound changes in the social, experiential and demographic context of individuals surviving in the study population. Population density, group size and number of helpers decreased, and the rate of group extinction/recolonization increased. In effect, this pulse of increased predation resulted in a unique natural experiment. Relative to conditions before increased predation, Poco das Antas now contains more breeding opportunities for dispersing individuals, less competition to fill those slots and fewer alloparents to care for group offspring.By comparing patterns of dispersal and reproductive sharing before and after increased predation, and by integrating molecular genetic and endocrine techniques with field data, these investigators propose to determine if tamarins are assessing the availability and quality of reproductive opportunities outside the natal group, the extent to which ecological constraints affect dispersal and reproductive sharing, the effects of genetic relatedness on subordinate breeding, the relative effects of inbreeding avoidance and age on reproductive skew, and the circumstances and mechanisms by which dominants control reproduction of subordinates. Finally, the presence of this NSF-sponsored project provides resources, prestige and incentive to the Brazilian government agency managing the reserve and serves as a platform for training Brazilian and American biologists at all professional levels. Results of this research form the scientific basis for management of all four taxa of lion tamarins and were used to justify the creation of a new biological reserve and to inform and implement local projects including reforestation, planting of forest corridors, conservation education, reintroduction and translocation.

虽然相对于其他社会系统罕见，合作繁殖的物种提供了独特的机会，以检查解释在亲属为基础的社会中的合作和竞争的演变的假设。 早期的研究集中在同种异体父母照顾的适应意义上。 具体来说，为什么成熟的成年人留在他们纳塔尔的群体中帮助抚养后代而不是自己的后代？ 对于各种鸟类和少数哺乳动物来说，在解决为什么帮手会帮助的原始问题方面已经取得了实质性的进展。 通过呆在家里，异源父母通常会提高他们找到繁殖机会的机会，并获得间接的适应性。 早期对圈养的马立克次灵长类（绒猴、绢毛猴和狮绢毛猴）的研究表明，社会和遗传上的一夫一妻制是家庭的规范，但最近来自野外和圈养环境的报告表明，马立克次的社会组织是高度灵活的，无论是在种群内还是在类群之间。 这种变异性为检验生殖偏斜和延迟扩散的基础假设提供了肥沃的土壤。Dietz，Baker和同事们建议对巴西Poco das Antas保护区的金狮绢毛猴进行为期3年的行为和人口统计学研究。 这项为期17年的研究在解决人口问题的能力和范围方面是独一无二的，它维护了一套综合数据库，包括行为，人口统计学，亲属关系，形态学，生殖，空间利用，群体动态，饮食习惯以及血液，毛发和粪便样本。 在这项研究的前13年，狮子绢毛猴领土占据了所有合适的栖息地在保护区，大多数群体包含几个帮手和人口增长是有限的高死亡率从纳塔尔群体扩散。 在过去的三年里，一种新的形式的捕食，在巢穴中的完整群体的杀戮，导致了在研究人群中生存的个人的社会，经验和人口背景的深刻变化。 种群密度、群体规模和帮手数量下降，群体灭绝/分化率上升。 实际上，这种增加的捕食脉冲导致了一个独特的自然实验。 相对于捕食增加之前的条件，Poco das Antas现在包含了更多的分散个体的繁殖机会，更少的竞争来填补这些空缺，更少的异源父母来照顾群体后代。通过比较捕食增加之前和之后的分散和生殖共享模式，并通过将分子遗传和内分泌技术与实地数据相结合，这些研究人员建议确定绢毛猴是否正在评估纳塔尔群体外生殖机会的可用性和质量，生态限制影响扩散和生殖共享的程度，遗传相关性对次级繁殖的影响，避免近亲繁殖和年龄对生殖偏斜的相对影响，以及显性个体控制下级个体生殖的环境和机制。最后，这个由国家科学基金会赞助的项目的存在为管理保护区的巴西政府机构提供了资源、声望和激励，并为培训巴西和美国各级专业生物学家提供了一个平台。 这项研究的结果形成了管理所有四个分类群的狮子绢毛猴的科学基础，并用于证明建立一个新的生物保护区的合理性，并为当地项目提供信息和实施，包括重新造林，种植森林走廊，保护教育，重新引入和迁移。