Linda I Hollen

The higher the better: sentinel height influences foraging success in a social bird

In all social species, information relevant to survival and reproduction can be obtained in two main ways: through personal interaction with the environment (i.e. ‘personal’ information) and from the performance of others (i.e. ‘public’ information). While public information is less costly to obtain than personal information, it may be inappropriate or inaccurate. When deciding how much to rely on public information, individuals should therefore assess its potential quality, but this possibility requires empirical testing in animals. Here, we use the sentinel system of cooperatively breeding pied babblers (Turdoides bicolor) to investigate how behavioural decisions of foragers are influenced by potential variation in the quality of anti-predator information from a vigilant groupmate. When sentinels moved to a higher position, from where their probability of detecting predators is likely to be greater, foragers reduced their vigilance, spread out more widely and were more likely to venture into the open. Consequently, they spent more time foraging and increased their foraging efficiency, resulting in a profound increase in biomass intake rate. The opposite behavioural changes, and consequent foraging outcomes, were found when sentinels moved lower. A playback experiment demonstrated that foragers can use vocal cues alone to assess sentinel height. This is the first study to link explicitly a measure of the potential quality of public information with a fitness measure from those relying on the information, and our results emphasize that a full understanding of the evolution of communication in complex societies requires consideration of the reliability of information.

SINGING FOR YOUR SUPPER: SENTINEL CALLING BY KLEPTOPARASITES CAN MITIGATE THE COST TO VICTIMS

Parasitism generally imposes costs on victims, yet many victims appear to tolerate their parasites. We suggest that in some cases this may be because parasites provide victims with mitigating benefits, paradoxically giving rise to selection for advertisement rather than concealment by parasites. We investigate this possibility using the interaction between an avian kleptoparasite, the fork‐tailed drongo (Dicrurus adsimilis), and one of its victims, the pied babbler (Turdoides bicolor). Combining field observations and a playback experiment, we demonstrate that a conspicuous vocal signal broadcast by drongos perched waiting to steal food from foraging babblers allows the latter to improve their own foraging efficiency, although not to the same extent as that experienced in response to conspecific sentinel calling. We argue that “sentinel” calling by drongos may originally have arisen as a means of manipulating babblers: because babblers find more food items and venture into the open more in response to these vocalizations, drongos are presented with more kleptoparasitism opportunities. However, the resulting benefit to babblers could be sufficient to reduce selection for the evolution of defenses against drongos, and the current situation may represent a rare example of an interspecific relationship in transition from a parasitism to a mutualism.

Mental health outcomes of developmental coordination disorder in late adolescence

To assess the relationship between developmental coordination disorder (DCD) and mental health outcomes in late adolescence.

A longitudinal investigation of childhood communication ability and adolescent psychotic experiences in a community sample

Background Some childhood speech and language impairments precede psychosis but it is not clear whether they also precede adolescent psychotic experiences and whether this association is specific to psychotic experiences. Methods Pragmatic language and expressive speech and language (parent-assessed using the Childrens Communication Checklist) at age 9 and psychotic experiences and depression at ages 12 and 18 were investigated in 7659 participants from the Avon Longitudinal Study of Parents and Children. Associations were investigated using multivariate modelling. Results Poorer pragmatic language at 9 years was associated with psychotic experiences at both ages (12 years OR 1.22, 95% CI 1.11, 1.34; 18 years OR 1.25, 95% CI 1.10, 1.41) but only with depression at 18 years (OR 1.10, 95% CI 1.00, 1.22). Poorer expressive speech and language ability was not associated with psychotic experiences or depression at either age. There was evidence that pragmatic language was specifically associated with psychotic experiences at age 12 but no evidence that the strength of any of the associations changed over time. Conclusions Deficits in pragmatic language precede early and late adolescent psychotic experiences and early adolescent depression. Interventions aimed at helping children improve pragmatic language skills may reduce the incidence of adolescent psychopathology and associated psychological disorder and dysfunction later in life.

Calling by concluding sentinels: coordinating cooperation or revealing risk?

Efficient cooperation requires effective coordination of individual contributions to the cooperative behaviour. Most social birds and mammals involved in cooperation produce a range of vocalisations, which may be important in regulating both individual contributions and the combined group effort. Here we investigate the role of a specific call in regulating cooperative sentinel behaviour in pied babblers (Turdoides bicolor). ‘Fast-rate chuck’ calls are often given by sentinels as they finish guard bouts and may potentially coordinate the rotation of individuals as sentinels, minimising time without a sentinel, or may signal the presence or absence of predators, regulating the onset of the subsequent sentinel bout. We ask (i) when fast-rate chuck calls are given and (ii) what effect they have on the interval between sentinel bouts. Contrary to expectation, we find little evidence that these calls are involved in regulating the pied babbler sentinel system: observations revealed that their utterance is influenced only marginally by wind conditions and not at all by habitat, while observations and experimental playback showed that the giving of these calls has no effect on inter-bout interval. We conclude that pied babblers do not seem to call at the end of a sentinel bout to maximise the efficiency of this cooperative act, but may use vocalisations at this stage to influence more individually driven behaviours.

Developmental and behavioural associations of burns and scalds in children:: a prospective population-based study

Objective To investigate child developmental and behavioural characteristics and risk of burns and scalds. Design Data on burns in children up to 11 years from 12 966 participants in the Avon Longitudinal Study of Parents and Children were linked to developmental profiles measured before the burn injury. Measures Preinjury profiles of the children derived from maternal questionnaires completed in pregnancy, and at 6, 18, 42, 47 and 54 months. Injury data collected by questionnaire at 6, 15 and 24 months and 3.5, 4.5, 5.5, 6.5, 8.5 and 11 years of age. Results Incidence: Burn rates were as follows: birth–2 years 71.9/1000/year; 2–4.5 years 42.2/1000/year; 5–11 years 14.3/1000/year. Boys <2 years were more likely to sustain burns, and girls had more burns between age 5 and 11 years. Medical attention was sought for 11% of burn injuries. Development: Up to age 2 years, burns were more likely in children with the most advanced gross motor developmental scores and the slowest fine motor development. Children with coordination problems at 4.5 years of age had increased risk of burns between 5 and 11 years. No associations were observed with cognitive skills. Behaviour: At 3.5 years, the Strengths and Difficulties Questionnaire scores and reported frequent temper tantrums predicted subsequent burns in primary school age. After adjustment for confounders, burns in the preschool period were related to gender and motor development, and in school-aged children, to frequent temper tantrums, hyperactivity and coordination difficulties. Conclusion Child factors associated with increased risk of burns were male gender in infancy and female gender at school age, advanced gross motor development, coordination difficulties, hyperactivity and problems with emotional regulation.

The impact of developmental coordination disorder on educational achievement in secondary school

Highlights • Adolescents 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.

Agents, mechanisms and clinical features of non-scald burns in children: a prospective UK study

AIMS To inform childhood burn prevention by identifying demographics, clinical features and circumstances of unintentional non-scald burns. METHODS A prospective cross-sectional study was conducted across Cardiff, Bristol and Manchester, including six emergency departments, three minor injury units and one burns unit between 13/01/2013-01/10/2015. Data collected for children aged <16 years with any burn (scald, contact, flame, radiation, chemical, electrical, friction) included: demographics, circumstances of injury and clinical features. Scalds and burns due to maltreatment were excluded from current analysis. RESULTS Of 564 non-scald cases, 60.8% were boys, 51.1% were <3 years old, 90.1% (472/524) of burns affected one anatomical site. Contact burns accounted for 86.7% (489/564), 34.8% (137/394) of which were from objects placed at >0.6m and 76.5% (349/456) affected the hands. Hairstyling devices were the most common agent of contact burns (20.5%, 100/487); 34.1% (30/88) of hairstyling devices were on the floor. Of children aged 10-15 years, 63.7% (65/102), sustained contact burns of which 23.2% (13/56) were preparing food, and when burnt from hairstyling devices, 73.3% (11/15) were using them at the time of injury. CONCLUSIONS Parents of toddlers must learn safe storage of hazardous items. Older children should be taught skills in safe cooking and hairstyling device use.

P02 Outcome of mild traumatic brain injury (tbi) in children- results from a prospective uk cohort study

Aim To use prospectively collected data to investigate the outcomes up to 16 years of TBI in childhood. Methods Data from the Avon Longitudinal Study of Parents and Children (ALSPAC) were analysed. Background demographics and developmental and behavioural profile of the children were derived from questionnaires completed by the mother in pregnancy, at 6 weeks and at 18 and 42 months. Injury data were derived from questionnaires completed by the child’s carer at 4½ 5½ 6½ 8 ½ and 11½ years of age. Outcomes were collected when the child was 11–16 years old, from ALSPAC questionnaires and research clinics, and from linked educational data. TBI cases (n = 410), defined as any head injury resulting in loss of consciousness and/or a skull fracture before the age of 11, were compared with children of the same age (n = 1819) who suffered traumatic orthopaedic injuries (fractures- excluding skull fractures). Controls (n = 8770) were all children with available injury data who did not have a TBI or orthopaedic injury. Results 410 ALSPAC participants (59% male) had a TBI before 11; 154 (38%) had a fractured skull, and 36 (9%) had multiple TBIs. Orthopaedic injuries were reported for 1819 participants (52% male) before 11. Compared to controls, children who had a TBI came from families living in adversity, with mothers with lower educational qualifications and a history of depression. The children who suffered a TBI had higher hyperactivity and conduct scores age 42 months, but no differences were apparent for those who later suffered orthopaedic injuries. Outcomes at 13–16 which remained associated with TBI after adjustment were the total behavioural problems score, the hyperactivity score and the conduct problems score of the SDQ, and high levels of anxiety and depression. Adjustment for pre-injury SDQ scores attenuated the associations with the SDQ scores but these remained significantly different from controls. Weak associations were also observed between orthopaedic injuries and later conduct problems. Conclusions TBI in childhood was associated with increased behavioural problems up to 16 years, and increased hyperactivity and conduct problems which were not explained by pre-injury characteristics. Depression and anxiety were also more common in TBI survivors.

Use of procalcitonin as a biomarker for sepsis in moderate to major paediatric burns

Introduction Accurate and early detection of sepsis poses a significant challenge in burn populations. Our objective was to assess whether procalcitonin is a marker of blood culture positive sepsis in moderate to severe paediatric burns. Methods We analysed procalcitonin levels in 27 children admitted with burns of 15–65% total body surface area. Procalcitonin was measured at admission (baseline), 24 and 48 h post-admission and during periods of suspected sepsis (diagnosed against pre-defined criteria). Patients were categorised into controls with no episodes of suspected sepsis (n = 10) and those with episodes of suspected sepsis (n = 17). The latter were split into two groups based on blood culture results: culture positive (bacteraemia) and culture negative patients. Results Baseline procalcitonin levels increased with burn size (odds ratio (95% confidence interval): 1.15 (1.02–1.29)). Suspected sepsis patients had larger burns than controls (median 31 vs. 20%; p = 0.003). Only 5/23 suspected sepsis episodes were blood culture positive. Procalcitonin levels were similar in culture positive and culture negative patients (p = 0.43). Sensitivity for predicting positive blood culture was 100% (95% confidence interval: 47.8–100.0%) but specificity was only 22.2% (95% confidence interval: 6.4–47.6%). Area under the curve was poor at 0.62 (95% confidence interval: 0.33–0.90). There was no significant change in procalcitonin levels from baseline to septic episode in either group (positive: p = 0.35; negative: p = 0.95). Conclusion We conclude that evidence for the use of procalcitonin to diagnose bacteraemia in this population is poor, with burn size playing a significant role implying a correlation with systemic inflammation rather than sepsis.