title: Early-Life Stress Triggers Juvenile Zebra Finches to Switch Social Learning Strategies.
abstract: Stress during early life can cause disease and cognitive impairment in humans and non-humans alike. However, stress and other environmental factors can also program developmental pathways. We investigate whether differential exposure to developmental stress can drive divergent social learning strategies between siblings. In many species, juveniles acquire essential foraging skills by copying others: they can copy peers (horizontal social learning), learn from their parents (vertical social learning), or learn from other adults (oblique social learning). However, whether juveniles' learning strategies are condition dependent largely remains a mystery. We found that juvenile zebra finches living in flocks socially learned novel foraging skills exclusively from adults. By experimentally manipulating developmental stress, we further show that social learning targets are phenotypically plastic. While control juveniles learned foraging skills from their parents, their siblings, exposed as nestlings to experimentally elevated stress hormone levels, learned exclusively from unrelated adults. Thus, early-life conditions triggered individuals to switch strategies from vertical to oblique social learning. This switch could arise from stress-induced differences in developmental rate, cognitive and physical state, or the use of stress as an environmental cue. Acquisition of alternative social learning strategies may impact juveniles' fit to their environment and ultimately change their developmental trajectories.
authors.affiliation: Edward Grey Institute of Field Ornithology, Department of Zoology, University of Oxford, Oxford OX1 3PS, UK; Department of Anthropology, University of California, Davis, Davis, CA 95616, USA; Smithsonian Tropical Research Institute, Panamá 0843-03092, Panama. Electronic address: damien.farine@zoo.ox.ac.uk.
authors.forename: Damien R
authors.initials: DR
authors.lastname: Farine
authors.affiliation: School of Psychology and Neuroscience, University of St. Andrews, St. Andrews KY16 9JP, UK.
authors.forename: Karen A
authors.initials: KA
authors.lastname: Spencer
authors.affiliation: School of Psychology and Neuroscience, University of St. Andrews, St. Andrews KY16 9JP, UK; Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, UK.
authors.forename: Neeltje J
authors.initials: NJ
authors.lastname: Boogert
mesh_terms: D000818:Animals; D005247:Feeding Behavior; D046369:Finches / Q000502:physiology*; D000067570:Social Learning; D013312:Stress, Physiological