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Many foraging animals face a fundamental tradeoff between predation and starvation. In a range of social species, this tradeoff has probably driven the evolution of sentinel behavior, where individuals adopt prominent positions to watch for predators while groupmates forage. Although there has been much debate about whether acting as a sentinel is a selfish or cooperative behavior, far less attention has focused on why sentinels often produce quiet vocalizations (hereafter known as "sentinel calls") to announce their presence. We use observational and experimental data to provide the first evidence that group members gain an increase in foraging success by responding to these vocal cues given by sentinels. Foraging pied babblers (Turdoides bicolor) spread out more, use more exposed patches, look up less often, and spend less time vigilant in response to sentinel calling. Crucially, we demonstrate that these behavioral alterations lead to an increase in biomass intake by foragers, which is likely to enhance survival. We argue that this benefit may be the reason for sentinel calling, making it a truly cooperative behavior.

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AimTo assess the relationship between developmental coordination disorder (DCD) and mental health outcomes in late adolescence.MethodData were analyzed from the Avon Longitudinal Study of Parents and Children. Moderate‐to‐severe DCD was defined at 7 to 8 years according to the DSM‐IV‐TR criteria. Mental health was assessed at 16 to 18 years using self‐reported questionnaires: Strengths and Difficulties Questionnaire, Short Moods and Feelings Questionnaire, and the Warwick–Edinburgh Mental Well‐being Scale. Logistic and linear regressions assessed the associations between DCD and mental health, using multiple imputation to account for missing data. Adjustments were made for socio‐economic status, IQ, and social communication difficulties.ResultsAdolescents with DCD (n=168) had an increased risk of mental health difficulties (total Strengths and Difficulties Questionnaire score) than their peers (n=3750) (odds ratio 1.78, 95% confidence interval 1.12–2.83, adjusted for socio‐economic status and IQ). This was, in part, mediated through poor social communication skills. Adolescent females with DCD (n=59) were more prone to mental health difficulties than males. Greater mental well‐being was associated with better self‐esteem (β 0.82, p<0.001).InterpretationIndividuals with DCD, particularly females, had increased risk of mental health difficulties in late adolescence. Interventions that aim to promote resilience in DCD should involve improving social communication skills and self‐esteem.

HighlightsAdolescents with DCD in the UK performed poorly compared to controls in standardised national exams (GCSE) at 16 years.Co-occurring difficulties with reading, social communication and hyperactivity affected performance in those with DCD.Many of those with DCD were not receiving any additional formal educational support.