Prolonged ovarian acyclicity is associated with a higher likelihood of developing hyperprolactinemia in zoo female African elephants

Hyperprolactinemia is a common disorder of the hypothalamic-pituitary axis, and a cause of ovarian dysfunction in women. Currently, over half of non-cycling African elephant females in North America also are hyperprolactinemic, suggesting a similar link between these two conditions may exist. The objective of this study was to determine the relationship between acyclicity and prolactin […]

Spontaneous egg or chick abandonment in energy-depleted king penguins: A role for corticosterone and prolactin?

Various exogenous or endogenous factors may induce an emergency response in birds, redirecting current activity towards survival. In fasting, breeding penguins, the achievement of a critical energy depletion was suggested to induce egg abandonment and departure to sea for re-feeding. How such a behavioral shift is hormonally controlled remains unknown. The possible involvement of corticosterone […]

Hormonal correlates of parental behavior in yellow-eyed penguins (Megadyptes antipodes)

Penguins show varying degrees of brood reduction behavior, from obligate brood reducers to brood maximizers, and we hypothesize that this is associated with differences in prolactin secretion. To address this hypothesis, we determined the breeding season prolactin profile of the yelloweyed penguin (Megadyptes antipodes) for comparison with those of other penguin species found in the […]

Endocrine and ultrasonographic characterization of a successful pregnancy in a Sumatran rhinoceros (Dicerorhinus sumatrensis) supplemented with a synthetic progestin

Abstract 10.1002/zoo.10131.abs A Sumatran rhinoceros with a history of early pregnancy loss was supplemented with a synthetic progestin, altrenogest (Regu-Mate®), and delivered a healthy, full-term calf 475 days after mating. Serum hormone concentrations were measured throughout gestation, and ultrasonography was used to monitor embryo/fetal growth and viability. The embryonic vesicle growth curve was characterized by […]

Mother–infant interactions in free-ranging rhesus macaques: Relationships between physiological and behavioral variables

Studies of mother–infant relationships in nonhuman primates have increasingly attempted to understand the neuroendocrine bases of interindividual variation in mothering styles and the mechanisms through which early exposure to variable mothering styles affects infant behavioral development. In this study of free-ranging rhesus macaques on Cayo Santiago, Puerto Rico, we aimed to: 1) compare lactating and […]

Elevated prolactin levels immediately precede decisions to babysit by male meerkat helpers

Recent studies suggest that decisions to care for the offspring of others in societies of cooperative vertebrates may have a hormonal basis. The crucial question of whether changes in hormone levels immediately precede or merely follow bouts of offspring care, however, remains largely unanswered. Here, we show that in wild groups of cooperatively breeding meerkats, […]

Hormonal changes related to paternal and alloparental care in common marmosets (Callithrix jacchus)

The physiological mechanisms of parental and alloparental care in cooperatively breeding nonhuman primate species such as the common marmoset (Callithrix jacchus) are poorly known. In this study, we examined prolactin and cortisol plasma levels of fathers and older offspring of both sexes, with and without previous experience in infant carrying, around parturition and during infant […]

Hormonal regulation of female nuptial coloration in a fish

Physiological color change in camouflage and mating is widespread among fishes, but little is known about the regulation of such temporal changes in nuptial coloration and particularly concerning female coloration. To better understand regulation of nuptial coloration we investigated physiological color change in female two-spotted gobies (Gobiusculus flavescens). Females of this species develop an orange […]

Social suppression of female reproductive maturation and infanticidal behavior in cooperatively breeding Mongolian gerbils

In several cooperatively breeding species, reproductively suppressed, nonbreeding females are attracted to infants and routinely provide alloparental care, while breeding females may attack or kill other females’ infants. The mechanisms underlying the transition from alloparental to infanticidal behavior are unknown. In this study, we tested the hypothesis that this transition is associated with cessation of […]

Diminished maternal responsiveness during pregnancy in multiparous female common marmosets

Common marmoset monkeys (Callithrix jacchus) live in small groups in which, usually, only a single female breeds and all group members provide infant care. When two females breed concurrently, however, they may commonly kill one another’s infants, especially during the peripartum period. To investigate the mechanisms underlying infanticide by breeding females, we characterized responses of […]