Physiological costs and carry-over effects of avian interspecific brood parasitism influence reproductive tradeoffs

Social Interactions between Adult and Juvenile Striped Cuckoos (Tapera naevia)

“…Once the Striped Cuckoo chick hatches, it kills its host nestmates within a few days and is raised alone by the host parents, which also provision the fledged parasitic chick up to 4-6 weeks (Payne 2005). During host provisioning, Striped Cuckoo fledglings move away from the center of the host territory, towards forest edges and open areas (Mark and Rubenstein 2013).…”

Glucocorticoids mediate egg rejection in a brood parasite host

“…So far, the only study that has investigated such links has found a weak 149 positive association between foreign egg acceptance and baseline corticosterone levels [25]. It is therefore 150 unclear if the increased acceptance of model eggs in response to mitotane in this study is mediated by 151 changes in baseline (as in [10]) or parasitism-related stress-induced [9] corticosterone levels. Indeed, our 152 treatment validation design only allowed us to test if mitotane could alleviate a major increase in 153 corticosterone levels in response to captivity stress.…”

“…Host adults show elevated baseline and stress-induced corticosterone levels in response to brood 135 parasitism [9,10]. Until now, the consequences of this endocrine response on host antiparasitic behaviours 136 have been unknown [8].…”

“…A handful of recent studies suggest that host responses to avian brood parasitism are, in part, 33 mediated by steroid hormones [8]. For example, host parents caring for a parasitic chick show higher 34 stress-induced corticosterone levels compared to parents caring for only their own young [9]. An increase 35 in the baseline corticosterone levels in hosts can occur directly in response to encountering a foreign egg 36 in the nest [10].…”

Full Issue

“…More studies on effects of brood parasitism on nestling diet could also measure passively deposited corticosterone in nestling feathers to quantify the degree of nutritional stress due to brood parasitism on host nestlings. In this way, potential carry-over effects of parasitism into subsequent years should be investigated for both host adults (Mark and Rubenstein 2013) and nestlings. Additionally, deliberate examination of how ecological interactions among Ca and food availability and parasitism rates affect diets of host nestlings, perhaps through simultaneous manipulation of brood parasite populations and methods described in this study, would be beneficial.…”