Exploring the Effect of Age on the Reproductive and Stress Physiology of Octopus bimaculoides Using Dermal Hormones
Our goal was to validate the use of dermal swabs to evaluate both reproductive and stress physiology in the California two-spot octopus, Octopus bimaculoides. Our objectives were to (1) use dermal swabs to evaluate glucocorticoids and reproductive hormones of O. bimaculoides; (2) determine the influence of life stage on hormone production (glucocorticoids in all individuals; […]
Non-invasive assessment of fecal glucocorticoid and androgen metabolites in the pygmy hippopotamus (Choeropsis liberiensis)
The pygmy hippopotamus (Choeropsis liberiensis) is an endangered species endemic to the Upper Guinea Forest ecosystem in West Africa. We have limited information concerning the species’ reproduction and well-being under managed care. We therefore developed non-invasive methods for characterizing gonadal androgen and adrenal hormone profiles in pygmy hippos using fecal samples collected from 12 males […]
Measurement of Fecal Testosterone Metabolites in Mice: Replacement of Invasive Techniques
Testosterone is the main reproductive hormone in male vertebrates and conventional methods to measure testosterone rely on invasive blood sampling procedures. Here, we aimed to establish a non-invasive alternative by assessing testosterone metabolites (TMs) in fecal and urinary samples in mice. We performed a radiometabolism study to determine the effects of daytime and sex on […]
Injections to pregnant mice produce prenatal stress that affects aggressive behavior in their adult male offspring
Maternal stress could reprogram the developing fetal nervous system. A common target of maternal glucocorticoids is fetal neuro-endocrine axis. In the present study, pregnant mice were exposed to stress by injection and their male offspring were tested for sexual and aggressive behaviors in adult life. Three groups of pregnant mice were exposed to stress by […]
Lizards perceived abiotic and biotic stressors independently when competing for shade in terrestrial mesocosms
Hormones such as glucocorticoids and androgens enable animals to respond adaptively to environmental stressors. For this reason, circulating glucocorticoids became a popular biomarker for estimating the quality of an environment, and circulating androgens are frequently used to indicate social dominance. Here, we show that access to thermal resources influence the hormones and behavior of male […]
Investigation of the efficacy of the GnRH agonist deslorelin in mitigating intraspecific aggression in captive male Amur leopards (Panthera pardus orientalis)
Housing bachelor groups is a necessary aspect of the care and husbandry of non-breeding individuals in zoological collections. Intraspecific aggressive behaviors may occur in this setting despite management strategies designed to mitigate these behaviors. Androgens (including testosterone) are associated with aggression in male species and interventional techniques to alter the animals’ physiology to modify aggressive […]
Hormonal correlations at transition from reproduction to molting in an annual life cycle of Humboldt penguins (Spheniscus humboldti)
To understand the hormonal mechanism behind a unique strategy of breeding and molting in Humboldt penguins, six pairs of captive Humboldt penguins kept in an outdoor open display pen were observed and blood collected weekly for a year. They all molted between the middle of June and the middle of August within 10 days except […]
Serum testosterone in captive male rhinoceros: Effects of season, age, stress, and sociosexual environment
All rhinoceros species are in some degree of endangerment. Understanding the reproductive physiology of rhinoceros species will help in management decisions with both free-ranging and captive populations. In mammalian species studied, testosterone plays a key role in spermatogenesis and libido. Testosterone concentrations, depending on the species, may vary according to age, season, social status, stress […]
Housing and welfare in laboratory rats: effects of cage stocking density and behavioural predictors of welfare
Using male and female Alderley Park (Wistar-derived) rats housed in single-sex groups in standard laboratory cages, we looked at the effect of group size (one, three, five or eight) on competitive behaviour and time budgeting (initial and longer term), changes in their serum testosterone (males), corticosterone and antibody concentrations, and organ pathology at age 16 […]
A safer method for studying hormone metabolism in an Asian elephant (Elephas maximus): accelerator mass spectrometry
Abstract Noninvasive hormone assays provide a way to determine an animal’s health or reproductive status without the need for physical or chemical restraint, both of which create unnecessary stress for the animal, and can potentially alter the hormones being measured. Because hormone metabolism is highly species-specific, each assay must be validated for use in the […]