The effects of neonatal handling on adrenocortical responsiveness, morphological development and corticosterone binding globulin in nestling American kestrels (Falco sparverius)

Abstract

This is an author-produced, peer-reviewed version of this article. © 2009, Elsevier. Licensed under the Creative Commons AttributionNonCommercial-NoDerivatives 4.0 International License (https://creativecommons.org/licenses/by-nc-nd/4.0/). The final, definitive version of this document can be found online at General and Comparative Endocrinology, doi: 10.1016/j.ygcen.2011.03.009 1 NOTICE: This is the author"s version of a work accepted for publication by Elsevier. Changes resulting from the publishing process, including peer review, editing, corrections, structural formatting and other quality control mechanisms, may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. The definitive version has been published in General and Comparative Endocrinology, 2011. DOI: 10.1016/j.ygcen.2011 The AbstractEarly developmental experiences play an important role in development of the adult phenotype. We investigated the effects of neonatal handling on the hypothalamic-pituitaryadrenal 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 in body condition index. Both total corticosterone (CORT) and CBG capacity were dampened significantly in H kestrels. However, free CORT did not differ between the two groups. In addition, hormone challenges of corticotropin releasing factor and adrenocorticotropin hormone were compared to saline injections to determine if the pituitary or the adrenal glands, respectively, were rendered more or less sensitive by handling. There was no difference in the responsiveness of H and NH kestrels to either hormone challenge. It is clear from these data that handling had an affect on fledgling phenotypic development, although whether the effects are permanent or ephemeral is unknown.

Strong effects of radio‐tags, social group and release date on survival of reintroduced grey partridges

“…There were no substantial effects of radio‐tags on plasma levels of corticosterone. This is in line with previous studies reporting transient (short‐term) but no sustained increases of physiological stress levels in response to capture and radio‐tagging of wild birds (Suedkamp Wells et al ., 2003; Whitman, Breuner & Duffy, 2011). Measurement of corticosterone in our case took place approximately 2 weeks after mounting radio‐tags.…”

Effects of developmental conditions on nestling American Kestrel (Falco sparverius) corticosterone concentrations

“…higher CORT concentrations), which may facilitate coping or lead to repercussions associated with chronically elevated CORT [13,9]. A lternatively, nestlings may respond with a down-regulated or dampened stress response [36,52] presumably to minimize the long-term negative effects elevated CORT has during development [49].…”

Assessing the effects of repeated handling on the physiology and condition of semi‐precocial nestlings

“…, Romero , Whitman et al . ). A dampening of the acute stress response following exposure to repeated neonatal handling has previously been attributed to acclimatization in captive and domesticated vertebrates (Meaney et al .…”

“…In altricial young, regular handling induced a dampening of the stress response in American Kestrels Falco sparverius (Whitman et al . ) and Eastern Bluebirds Sialia sialis (Lynn et al . ), whereas European Shag Phalacrocorax aristotelis nestlings showed increased sensitivity of the HPA axis but no change in baseline GCs (Herborn et al .…”