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Full-Text Articles in Life Sciences
Effects Of Developmental Conditions On Nestling American Kestrel (Falco Sparverius) Corticosterone Concentrations, Erin H. Strasser, Julie A. Heath
Effects Of Developmental Conditions On Nestling American Kestrel (Falco Sparverius) Corticosterone Concentrations, Erin H. Strasser, Julie A. Heath
Biology Faculty Publications and Presentations
How nestling birds respond to stressful situations may constitute an important survival component that has lasting developmental effects on the hypothalamic pituitary adrenal (HPA) axis. As birds are exposed to increasing amounts of potential anthropogenic stressors through land use change, understanding how these factors contribute to HPA development is important. We examined whether conditions experienced during the nestling stage affected free-living American Kestrel (Falco sparverius) HPA activity prior to fledging. Kestrels experienced varying levels of human disturbance around their nest and we classified this environmental exposure as high or low environmental human disturbance based on traffic patterns and …
The Effects Of Neonatal Handling On Adrenocortical Responsiveness, Morphological Development And Corticosterone Binding Globulin In Nestling American Kestrels (Falco Sparverius), Buddy A. Whitman, Creagh W. Breuner, Alfred M. Dufty
The Effects Of Neonatal Handling On Adrenocortical Responsiveness, Morphological Development And Corticosterone Binding Globulin In Nestling American Kestrels (Falco Sparverius), Buddy A. Whitman, Creagh W. Breuner, Alfred M. Dufty
Biology Faculty Publications and Presentations
Early developmental experiences play an important role in development of the adult phenotype. We investigated the effects of neonatal handling on the hypothalamic-pituitary-adrenal axis in a free-living avian species, the American kestrel (Falco sparverius). In the handled group (H), kestrel chicks were handled for 15 min/day from hatching until 26 days of age, after which time blood samples were collected for analysis of adrenal responsiveness and corticosterone binding globulin (CBG) levels. The non-handled control group (NH) was left undisturbed until 26 days of age when blood samples were collected and analyzed as above. Handled and NH kestrels did not differ …
Stress Responsiveness In Nestlings: A Comparison Of Two Sampling Techniques, Alfred M. Dufty
Stress Responsiveness In Nestlings: A Comparison Of Two Sampling Techniques, Alfred M. Dufty
Biology Faculty Publications and Presentations
I compared the effects on plasma corticosterone levels of two methods of collecting blood samples during standardized capture and handling stress protocols. In one method, individual nestling American Kestrels (Falco sparverius) were bled at three time periods: when initially removed from the nest, and 15 and 30 min later. In the other method, siblings removed from a nest were bled once each, either at the time of removal, or 15 or 30 min later. I found that there was no difference between the two groups in plasma corticosterone levels at the first sampling period, but 15 and 30 min after …
Corticosterone Levels During Nest Departure Of Juvenile American Kestrels, Julie Heath
Corticosterone Levels During Nest Departure Of Juvenile American Kestrels, Julie Heath
Biology Faculty Publications and Presentations
Many avian behavior patterns, such as breeding, migration and territoriality, are correlated with changes in hormone levels. Elevated levels of corticosterone, an adrenal steroid hormone, are associated with increased foraging and increased activity levels in birds. Young birds about to take their first flight may benefit from elevated plasma corticosterone levels that facilitate locomotor activity and foraging behavior while they are developing flight and hunting skills. I examined the relationship between corticosterone levels and the timing of nest departure in nestling American Kestrels (Falco sparverius). American Kestrels are cavity nesters and typically depart from the nest between 25-30 …
Plumage Variation, Plasma Steroids And Social Dominance In Male House Finches, James R. Belthoff, Alfred M. Dufty Jr., Sidney A. Gauthreaux Jr.
Plumage Variation, Plasma Steroids And Social Dominance In Male House Finches, James R. Belthoff, Alfred M. Dufty Jr., Sidney A. Gauthreaux Jr.
Biology Faculty Publications and Presentations
In male House Finches (Carpodacusm exicanus), the extent and color of plumage varies depending on access to carotenoid pigments. "Colorful" males exhibit extensive red pigmentation, while less colorful (i.e., "drab") males exhibit carotenoid pigmentation over a smaller percentage of their plumage, pigmentation of a color besides red (e.g., yellow, gold, orange, or pink), or both. One explanation for maintenance of plumage variation is that it reliably reflects social status, allowing males to correctly assess their status in relation to others and avoid or minimize costly fights. Social relationships may also be related to endogenous factors, such as circulating levels of …