Early-life adversity increases foraging for food and for information in European starlings, Sturnus vulgaris (#138)
Knowledge of the causes of individual variation in foraging and eating behaviour is important for better understanding animal personality as well as the ontogeny of food-related conditions in humans, such as obesity. Animals can insure themselves against the risk of starvation associated with unpredictable food availability by storing energy reserves, or gathering information about alternative food sources. The former strategy carries costs in terms of predation risk, while the latter trades-off against foraging for food; both trade-offs may be influenced by an individual’s developmental history. Here, we consider a possible role of early developmental experience in inducing different mass regulation and foraging strategies in European starlings. We measured the body mass, body condition, foraging effort, food consumption and information gathering (contrafreeloading) of birds that had previously undergone a subtle early-life manipulation of food competition that impacted developmental stress biomarkers, but did not affect growth. We found that developmentally disadvantaged birds were fatter in adulthood and differed in foraging behaviour compared to their advantaged siblings. Disadvantaged birds were hyperphagic compared to advantaged birds, but only following a period of food-deprivation. Disadvantaged birds spent more time contrafreeloading than advantaged birds. Advantaged birds experienced a trade-off between foraging success and time spent contrafreeloading, while disadvantaged birds faced no such trade-off owing to their greater foraging efficiency. Thus, developmentally disadvantaged birds appeared to retain a phenotypic memory of increased nestling food competition, employing both energy storage and information-gathering insurance strategies to a greater extent than did their advantaged siblings. Our results suggests that subtle early life disadvantage in the form of psychosocial stress and/or food insecurity can leave a lasting legacy on foraging behaviour and mass regulation even in the absence of food insufficiency during development or adulthood.