Terminal investment and senescence in rhesus macaques (Macaca mulatta) on Cayo Santiago
Long-lived iteroparous species often show aging-related changes in reproduction that may be explained by 2 non-mutually exclusive hypotheses. The terminal investment hypothesis predicts increased female reproductive effort toward the end of the life span, as individuals have little to gain by reserving effort for the future. The senescence hypothesis predicts decreased female reproductive output toward […]
Maternal Investment in Captive Giraffes
Sex-biased maternal investment involves differential allocation of resources to production and rearing of sons or daughters as a function of their anticipated reproductive output. We examined reproductive investment among captive giraffes (Giraffa camelopardalis) over a 21-year period to determine extent to which females invest differentially in offspring by sex. We found an unbiased sex ratio […]
Maternal deposition of yolk corticosterone in clutches of southern rockhopper penguins (Eudyptes chrysocome chrysocome)
High corticosterone levels can have deleterious effects in developing avian embryos and chicks. Therefore, it may be adaptive for avian mothers to reduce corticosterone transfer to their eggs. However, until now, data about the active or/and passive role of mothers in corticosterone transfer to eggs are inconclusive. Here, we study maternal investment into A- and […]
Neonatal Milestones, Behavior and Growth Rate of Sumatran Rhinoceros (Dicerorhinus sumatrensis) Calves Born and Bred in Captivity
The birth of Sumatran rhino calves at the Cincinnati Zoo and Botanical Garden offered a unique opportunity to study early development and cow–calf behavior in this elusive, critically endangered species. Study goals were to: (1) record developmental milestones of newborn calves; (2) characterize cow and calf behavior during the first year following birth; (3) compare […]
Female canaries invest more in response to an exaggerated male trait
Females choose their mate on the basis of secondary sexual characters such as physical ornaments, courtship behaviours or vocalizations. In male birds, vocalizations are known to increase their attractiveness and consequently their probability of copulation. Moreover, male songs have been shown to shape maternal investment, particularly with regard to egg quality. Artificial manipulation of male […]