Corticosterone exposure during development has sustained but not lifelong effects on body size and total and free corticosterone responses in the zebra finch

Reference levels for corticosterone and immune function in farmed saltwater crocodiles (Crocodylus porosus) hatchlings using current Code of Practice guidelines

“…Similarly, nestling zebra finches treated with CORT exhibited suppressed body size 30 days after hatching but no effect was observed at 60 or 90 days post hatch (Crino et al, 2014). Whilst increased CORT post-hatch may reduce growth, this cost may be offset by other benefits such as increased foraging, aggression, food intake, or increased risk taking behaviour both in early and adult life (Kitaysky et al, 2003;Zimmer et al, 2013).…”

Developmental stress: evidence for positive phenotypic and fitness effects in birds

“…Numerous studies have found that developmental stress organizes the neuroendocrine pathway responsible for CORT output (the hypothalamicpituitary-adrenal or HPA axis) such that animals exposed to stressors during development respond more strongly to stressors as adults (but see Crino et al 2014a). For example, nestling zebra finches fed CORT during the nestling period respond to stressors with greater CORT output in adulthood (Kriengwatana et al 2014;Spencer et al 2009).…”

“…Prenatal treatment is generally done through maternal implant (e.g., Hayward and Wingfield 2004) or direct application to the egg (e.g., Love and Williams 2008a). Postnatal treatment is accomplished primarily through oral administration (e.g., Crino et al 2014a;Spencer and Verhulst 2007), but dermal patches (e.g., Wada and Breuner 2008) and hormone implants (e.g., Roulin et al 2008) have been used as well. Prenatal CORT treatment simulates an environment that is stressful for the mother during egg production.…”

“…Both techniques have strengths and weaknesses, and depending on the given question, one type of manipulation may be more appropriate than the other. For example, food restriction experiments (especially those where parents are handicapped or clutch size is experimentally increased) are more logistically feasible in free-living birds compared to CORT manipulations, which often employ methods that require nestlings be treated after they fledge from the nest (e.g., Crino et al 2014a;Spencer et al 2009). Food restriction, where parents are handicapped or provided with substandard food, also affects all nestlings in a nest and does not allow for intra-nest comparisons.…”

“…For example, in birds, developmental stress decreases immune function, suppresses growth, decreases neural function, and can suppress the expression of sexually selected traits in adulthood Carmona-Isunza et al 2013;e.g., Chin et al 2013;Crino et al 2014a; but see Gil et al 2006). Indeed, it is difficult to see how these effects are anything but negative.…”