| modulation of the hypothalamic-pituitary-adrenal axis of an arctic-breeding polygynandrous songbird, the smith's longspur, calcarius pictus. | to successfully reproduce in the arctic, birds must modulate their neuroendocrine and behavioural systems. these adjustments include an attenuation of the stress responsiveness of the hypothalamic-pituitary-adrenal (hpa) axis to external stimuli and a behavioural insensitivity to high corticosterone (b) levels. the hpa axis was examined in free-living territorial polygynandrous smith's longspurs (calcarius pictus) that migrate to breed on the arctic tundra. basal and stress-induced b levels were ... | 2003 | 12964988 |