Socioendocrinology of Cooperative Breeding

9723842 French在哺乳动物中，对婴儿的照料通常只限于对母亲的照料。然而，在一小部分物种中，父亲和其他群体成员参与照顾和供养受抚养的婴儿（分别是父亲和异父照顾）。虽然我们对这种照顾的模式了解很多，但很少有人关注调节母亲以外的个体提供亲代照顾的潜在机制。提出的研究将检查在黑色簇耳狨猴（Callithrix kuhli）亲代照顾的生理和经验决定因素。在狨猴中，母性的努力主要限于哺乳，成年雄性和年龄较大的后代提供大部分照顾依赖的婴儿。初步观察表明，生活在家庭群体中的年长儿子和父亲在婴儿在场的情况下经历乳房发育，这表明男性在照顾婴儿方面参与了内分泌。通过使用不引人注目的行为观察和无创尿液样本收集，French将测试对婴儿的反应程度和父母行为水平受到性腺类固醇（雌激素、孕酮和睾酮）和垂体肽（催乳素）的影响。将通过比较狨猴和松鼠猴（一种非父系物种）对婴儿相关刺激的内分泌反应来测试对婴儿生理反应的普遍性或特异性。此外，男性和女性伴侣之间的社会依恋的强度，被认为是对男性亲代照顾的进化至关重要的，将通过向伴侣提供对伴侣完整性的各种威胁（例如，暂时分离，遇到陌生人）来测试。总之，这些项目将提供关于控制对婴儿和成年社会伙伴的反应机制的见解，在一个以高水平的雄性父母照顾和强烈的异性关系为特征的物种中。

9723842 French Among mammals, infant care is commonly limited to maternal care. However, in a small proportion of species, fathers and other group members contribute to the care and provisioning of dependent infants (paternal and alloparental care, respectively). Although we know much about the patterning of this care, little attention has been directed toward the underlying mechanisms that regulate the delivery of parental care by individuals other than the mother. The studies proposed will examine the physiological and experiential determinants of parental care in the black tufted-ear marmoset (Callithrix kuhli). In the marmoset, maternal effort is limited essentially to nursing, and adult males and older offspring provide the majority of care to dependent infants. Initial observations indicate that older sons and fathers living in family groups undergo breast elaboration in the presence of infants, suggesting an endocrine involvement in infant care by males. Through the use of unobtrusive behavioral observations and noninvasive urine sample collection, French will test the degree to which responsiveness to infants and levels of parental behavior are affected by gonadal steroids (estrogen, progesterone, and testosterone) and pituitary peptides (prolactin). The generality or specificity of the physiological responses to infants will be tested by comparing the endocrine responses of both marmosets and squirrel monkeys (a non-paternal species) to infant-associated stimuli. Further, the strength of the social attachment between male and female partners, assumed to be critical for the evolution of male parental care, will be tested by providing pairs with a variety of threats to the integrity of the pair (e.g., temporary separations, encounters with strangers). Together, these projects will provide insights into the mechanisms that control responsiveness to infants and adult social partners in a species characterized by high levels of male parenta l care and strong heterosexual relationships.