title: Early life adversity increases foraging and information gathering in European starlings,Sturnus vulgaris.
abstract: 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 mass-dependent 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 contrafreeloading (foraging for food hidden in sand when equivalent food is freely available) of adult birds (≥10 months old) that had previously undergone a subtle early life manipulation of food competition (cross-fostering into the highest or lowest ranks in the brood size hierarchy when 2-12 days of age). We found that developmentally disadvantaged birds were fatter in adulthood and differed in foraging behaviour compared with their advantaged siblings. Disadvantaged birds were hyperphagic compared with advantaged birds, but only following a period of food deprivation, and also spent more time contrafreeloading. Advantaged birds experienced a trade-off between foraging success and time spent contrafreeloading, whereas 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 their advantaged siblings. Our results suggest 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.
authors.affiliation: Centre for Behaviour and Evolution, Institute of Neuroscience and Newcastle University Institute of Ageing, Newcastle University, Newcastle upon Tyne, U.K.
authors.forename: Clare
authors.initials: C
authors.lastname: Andrews
authors.affiliation: Centre for Behaviour and Evolution, Institute of Neuroscience and Newcastle University Institute of Ageing, Newcastle University, Newcastle upon Tyne, U.K. ; Département de Biologie, École Normale Supérieure de Lyon, Université de Lyon, Lyon, France.
authors.forename: Jérémie
authors.initials: J
authors.lastname: Viviani
authors.affiliation: Centre for Behaviour and Evolution, Institute of Neuroscience and Newcastle University Institute of Ageing, Newcastle University, Newcastle upon Tyne, U.K.
authors.forename: Emily
authors.initials: E
authors.lastname: Egan
authors.affiliation: Centre for Behaviour and Evolution, Institute of Neuroscience and Newcastle University Institute of Ageing, Newcastle University, Newcastle upon Tyne, U.K.
authors.forename: Thomas
authors.initials: T
authors.lastname: Bedford
authors.affiliation: Centre for Behaviour and Evolution, Institute of Neuroscience and Newcastle University Institute of Ageing, Newcastle University, Newcastle upon Tyne, U.K. ; School of Biological Sciences, Plymouth University, Plymouth, U.K.
authors.forename: Ben
authors.initials: B
authors.lastname: Brilot
authors.affiliation: Centre for Behaviour and Evolution, Institute of Neuroscience and Newcastle University Institute of Ageing, Newcastle University, Newcastle upon Tyne, U.K.
authors.forename: Daniel
authors.initials: D
authors.lastname: Nettle
authors.affiliation: Centre for Behaviour and Evolution, Institute of Neuroscience and Newcastle University Institute of Ageing, Newcastle University, Newcastle upon Tyne, U.K.
authors.forename: Melissa
authors.initials: M
authors.lastname: Bateson
keywords: European starling; Sturnus vulgaris; body mass regulation; contrafreeloading; developmental stress; early life adversity; food insecurity; foraging