A memory of hunger: effects of early-life adversity on adult foraging behaviour in European starlings. — ASN Events

A memory of hunger: effects of early-life adversity on adult foraging behaviour in European starlings. (#590)

Melissa Bateson 1
  1. Newcastle University, Newcastle, United Kingdom

Behavioural ecology has provided many examples of how the behaviour of animals can respond adaptively to changes in their current state. In most of these cases, the states studied are reversible, short-term states such as level of fat reserves. However, it is also possible for an animal’s state to be permanently altered by the conditions that it experiences early in its development. In my talk I will explore the hypothesis that animals could develop adaptive behavioural responses to the state that they have been dealt by their early developmental experience. We call this type of adaptive developmental plasticity (ADP) somatic-state based ADP to distinguish it from the more commonly discussed informational ADP, in which animals develop a phenotype that adapts them to a future environment predicted by a cue received during development. For the past three years, we have been using the European starling (Sturnus vulgaris) as a model in which to explore how early-life adversity alters both state and adult food-related cognition and behaviour. We have developed short, post-hatching experimental manipulations of both food restriction and/or psychosocial stress, inspired by the consequences of natural variation in brood size in starlings. As a measure of how these manipulations affect state we have been using erythrocyte telomere length (ETL). ETL is a measure of cellular aging, that we argue provides an integrative biomarker of the cumulative stress experienced by a developing bird, and also prospectively predicts its future morbidity and mortality. Using a range of different foraging tasks we have shown that birds with poorer state, as indexed by shorter ETL, also show a suite of changes in foraging behaviour, including being faster to approach known food sources, faster to investigate unknown food sources and more impulsive when given a choice between a small immediate reward and a larger, but more delayed reward. Together these differences are suggestive of a “psychology of hunger” similar to that seen in acutely hungry animals. I suggest that this adult psychological phenotype could be an adaptive, plastic response to the impaired state of the birds, and hence a case of somatic state-based ADP. I end by discussing how we can test whether a particular case of developmental plasticity is adaptive and how we could distinguish somatic-state based plasticity from informational plasticity.