Reproductive and post-reproductive hormone levels in the lizard Sceloporus virgatus
No abstract available.
Androgen levels in a Bornean voiceless frog, Rana blythi
Male Rana blythi and males of three other species of voiceless frogs from Bornean rain forests lack the suite of secondary sex characteristics typical of most anurans: nuptial pads, vocal sacs, enlarged forearm flexors, and male advertisement calls. At the same time, basal species in the voiceless frog lineage exhibit an extreme type of male […]
Rapid suppression of testosterone secretion after capture in male American alligators (Alligator mississippiensis)
All reptiles studied to date show an increase in circulating corticosterone following capture. This rise in corticosterone has also been shown in a number of instances to result in a decline in reproductive steroids within hours after capture. As a result of these observations it has been considered imperative to collect blood samples as soon […]
Sex differences in physiology and behavior: Focus on central actions of ovarian hormones
The use of saliva cortisol, urinary cortisol, and catecholamine measurements for a noninvasive assessment of stress responses in dogs
A problem in assessing animal welfare is that collecting data in itself may be stressful to the animals. Therefore, noninvasive methods for collecting data have to be devised and tested. A first step in investigating saliva cortisol, urinary cortisol, and urinary catecholamine as noninvasive indicators of canine well-being is the validation of these hormonal measures […]
Physiological stress in ecology – lessons from biomedical research
Increasingly, levels of the ‘stress hormones’ cortisol and corticosterone are being used by ecologists as indicators of physiological stress in wild vertebrates. The amplitude of hormonal response is assumed to correlate with the overall health of an animal and, by extension, the health of the population. However, much of what is known about the physiology […]
Impact of social management on reproductive, adrenal and behavioural activity in the cheetah (Acinonyx jubatus)
Cheetahs (Acinonyx jubatus) held ex situ can provide an important resource for obtaining new biological information that usually cannot be gleaned from free-living individuals. However, consistent captive propagation of the cheetah, a prerequisite for establishing a self-sustaining population, has not been accomplished so far. This study examined the effect of a husbandry regimen commonly used […]
Effect of stress on the activity of the hypothalamic-pituitary-gonadal axis: peripheral and central mechanisms.
This article reviews the mechanisms believed to mediate stress-induced inhibition of reproductive functions and the anatomical sites at which these effects take place. Particular emphasis is placed on the potential modulating role of hormones or neurotransmitters released during stress. At the level of the gonads, adrenal corticoids, pro-opiomelanocortin (POMC)-like peptides, and corticotropin-releasing factor (CRF) are […]