The predation stress hypothesis posits that exposure to predators and/or predator cues causes release of glucocorticoid hormones which coordinate behavioural responses that facilitate predator avoidance. We measured responses to short-term and repeated exposure to predator-derived kairomones in Allegheny Mountain dusky salamanders (Desmognathus ochrophaeus). Salamanders expressed predator avoidance behaviours (reduced locomotion, reduced mating behaviour) in the presence of predator kairomones. However, plasma glucocorticoids after short-term exposure to predator kairomones were similar to levels after exposure to controls. After repeated exposure to predator-derived kairomones, locomotory activity and plasma glucocorticoids were similar compared to controls. There was no evidence of habituation to predator kairomones. Overall, results did not support the predation stress hypothesis in Allegheny Mountain dusky salamanders in either an acute or chronic context. Use of glucocorticoids to mediate antipredator responses may occur when predation pressure is unpredictable, and when energetic and opportunity costs of linking glucocorticoids to anti-predator responses are low.
The neurological ecology of fear: insights neuroscientists and ecologists have to offer one another. —
Front. Behav. Neurosci.4: 21.
Excessive testicular progesterone secretion in age male Fischer 344 rats: a potential casue of age-related gonadotropin suppression and counfounding variable in aging studies. —
Exposure of goldfish (Carassius auratus) to bluegills (Lepomis macrochirus) enhances expression of stress protein 70 mRNA in the brains and increases plasma cortisol levels. —
Corticosterone increases depression-like behavior, with some effects on predator odor-induced defensive behavior, in male and female rats. —
Effect of human presence and handling on circulating corticosterone levels in breeding blue tits (Parus caeruleus). —
Gen. Comp. Endocrinol.148:
Stress in the wild: chronic predator pressure and acute restraint affect plasma DHEA and corticosterone levels in a songbird. —
Corticosterone treatment has subtle effects on thermoregulatory behavior and raises metabolic rate in the New Zealand common gecko, Hoplodactylus maculatus. —
Physiol. Biochem. Zool.81:
Environmental acidification is not associated with altered plasma corticosterone levels in the stream-side salamander, Desmognathus ochrophaeus. —
Gen. Comp. Endocrinol.201: