Reproductive assessment of the great hornbill (Buceros bicornis) by fecal hormone analysis
Abstract 10.1002/zoo.10083.abs The population of great hornbills (Buceros bicornis) in the United States is rapidly aging, and captive breeding efforts have not met population managers’ expectations for a sustainable captive group. Little is known about the reproductive physiology of these birds. This study reports the first data on the re-productive endocrinology of the great hornbill. […]
Transgenerational Effects of Early Experience on Behavioral, Hormonal and Gene Expression Responses to Acute Stress in the Precocial Chicken
Stress during early life can profoundly influence an individual’s phenotype. Effects can manifest in the short-term as well as later in life and even in subsequent generations. Transgenerational effects of stress are potentially mediated via modulation of the hypothalamic–pituitary–adrenal axis (HPA) as well as epigenetic mechanisms causing heritable changes in gene expression. To investigate these […]
Hormonal Correlates of Paternal Care Differences in the Hylobatidae
Only one of the 15 species of monogamous hylobatids, the siamang (Symphalangus syndactylus), demonstrates direct paternal care in the form of infant-carrying, providing a unique model for examining hormonal correlates of paternal care differences between siamangs and gibbons. We used behavioral data and fecal hormone analysis to investigate (1) differences in monthly percent father–infant proximity […]
Age dependent differences in the regulation of hippocampal steroid hormones and receptor genes: Relations to motivation and cognition in male rats
Abstract Estrogen and estrogenic functions are age-dependently involved in the modulation of learning, memory and mood in female humans and animals. However, the investigation of estrogenic effects in males has been largely neglected. Therefore, we investigated the hippocampal gene expression of estrogen receptors α and β (ERα, β) in 8-week-old, 12-week-old and 24-week-old male rats. […]
Experimental induction of social instability during early breeding does not alter testosterone levels in male black redstarts, a socially monogamous songbird
Testosterone plays an important role in territorial behavior of many male vertebrates and the Challenge Hypothesis has been suggested to explain differences in testosterone concentrations between males. For socially monogamous birds, the challenge hypothesis predicts that testosterone should increase during male–male interactions. To test this, simulated territorial intrusion (STI) experiments have been conducted, but only […]
Neuroplasticity in the maternal hippocampus: Relation to cognition and effects of repeated stress
This article is part of a Special Issue “Parental Care”. It is becoming clear that the female brain has an inherent plasticity that is expressed during reproduction. The changes that occur benefit the offspring, which in turn secures the survival of the mother’s genetic legacy. Thus, the onset of maternal motivation involves basic mechanisms from […]