Publications by authors named "Diego Javier Valdez"

Birds tend to adjust their behavior and physiology to changes in food availability in their environment. Seasonal fluctuation of food resources may act as an energetic challenge, augmenting hypothalamus-pituitary-adrenal axis (HPA axis) activity, leading to an increase in corticosterone concentrations and promoting the metabolism of energy stores. Plant invasions may alter seasonal food fluctuations by providing a food supply during scarce seasons.

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For birds, plumage color perception is critical in social interactions such as courtship, in both monochromatic and dichromatic species. In the Eared Dove (Zenaida auriculata), perhaps the most abundant South American Columbiforme, the plumage of males and females looks alike and both sexes share the same melanistic coloration with gray and pink tones. The aim of this study was therefore to determine whether evident sexual dichromatism exists in the plumage of the Eared Dove using a spectrophotometry technique in the avian-visible range (300-700 nm).

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The present study examined the participation of the anterodorsal thalamic nuclei (ADTN) in mediating the long-term effects of early maternal separation on the stress/hypothalamic-pituitary-adrenal axis response of adult animals. The study measured Fos and glucocorticoid receptor immunoreactivity (GR-ir) in the ADTN of maternally separated female rats subsequently exposed to variable chronic stress. Maternal separation increased the number of neurons immunoreactive to Fos in the ADTN of chronically stressed adult rats.

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