Program in Behavior, Ecology, Evolution and Systematics, University of Maryland, College Park, MD 20742, USA.
Horm Behav. 2013 May;63(5):675-83. doi: 10.1016/j.yhbeh.2013.02.009. Epub 2013 Feb 27.
Across taxa, cooperative breeding has been associated with high reproductive skew. Cooperatively breeding golden lion tamarins (Leontopithecus rosalia) were long thought to have a monogynous mating system in which reproduction was limited to a single dominant female. Subordinates with few reproductive opportunities delayed dispersal and remained in the natal group to provide alloparental care to siblings, thus allowing dominant reproductive females to meet the energetic needs associated with high rates of reproduction and successful infant rearing. The goal of this study was to re-assess monogyny in wild golden lion tamarin groups based upon pregnancy diagnoses that used non-invasive enzyme immunoassay for progesterone and cortisol, combined with weekly data on individual weight gain, bi-annual physical examinations noting pregnancy and lactation status and daily behavioral observations. We established quantitative and qualitative criteria to detect and determine the timing of pregnancies that did not result in the birth of infants. Pregnancy polygyny occurred in 83% of golden lion tamarin groups studied. The loss of 64% of subordinate pregnancies compared to only 15% by dominant females limited reproductive success mainly to dominant females, thus maintaining high reproductive skew in female golden lion tamarins. Pregnancy loss by subordinate adults did not appear to result from dominant interference in subordinate hormonal mechanisms, but more likely resulted from subordinate abandonment of newborn infants to mitigate dominant aggression.
跨物种，合作繁殖与高生殖偏斜有关。合作繁殖的金狮狨（Leontopithecus rosalia）长期以来被认为具有单配制交配系统，其中繁殖仅限于单一占优势的雌性。繁殖机会较少的下属会延迟扩散并留在出生地群体中，为兄弟姐妹提供亲代照顾，从而使占优势的生殖雌性能够满足与高繁殖率和成功养育婴儿相关的能量需求。本研究的目的是重新评估野生金狮狨群体中的单配制，方法是使用非侵入性的孕酮和皮质醇酶免疫分析进行妊娠诊断，结合个体体重增加的每周数据、每两年进行一次的妊娠和哺乳期身体检查以及每日行为观察。我们建立了定量和定性标准来检测和确定未导致婴儿出生的妊娠时间。83%的研究金狮狨群体中出现了妊娠多配偶制。与主要由优势雌性主导的繁殖成功相比，从属雌性的妊娠损失率高达 64%，这主要限制了从属雌性的生殖成功，从而维持了雌性金狮狨的高生殖偏斜。从属成年个体的妊娠损失似乎不是由于优势雌性对从属雌性激素机制的干扰造成的，而是更可能是从属雌性为减轻优势雌性的攻击而放弃新生婴儿的结果。
