Diurnal variation in the production of vocal information about food supports a model of social adjustment in wild songbirds.

Wintering songbirds have been widely shown to make economic foraging decisions to manage the changing balance of risks from predation and starvation over the course of the day. In this study, we ask whether the communication and use of information about food availability differ throughout the day. First, we assessed temporal variation in food-related vocal information produced in foraging flocks of tits ( Paridae) using audio recordings at radio-frequency identification-equipped feeding stations. Vocal activity was highest in the morning and decreased into the afternoon. This pattern was not explained by there being fewer birds present, as we found that group sizes increased over the course of the day. Next, we experimentally tested the underlying causes for this diurnal calling pattern. We set up bird feeders with or without playback of calls from tits, either in the morning or in the afternoon, and compared latency to feeder discovery, accumulation of flock members, and total number of birds visiting the feeder. Irrespective of time of day, playbacks had a strong effect on all three response measures when compared to silent control trials, demonstrating that tits will readily use vocal information to improve food detection throughout the day. Thus, the diurnal pattern of foraging behaviour did not appear to affect use and production of food-related vocalizations. Instead, we suggest that, as the day progresses and foraging group sizes increase, the costs of producing calls at the food source (e.g. competition and attraction of predators) outweigh the benefits of recruiting group members (i.e. adding individuals to large groups only marginally increases safety in numbers), causing the observed decrease in vocal activity into the afternoon. Our findings imply that individuals make economic social adjustments based on conditions of their social environment when deciding to vocally recruit group members.

A high-density SNP chip for genotyping great tit (Parus major) populations and its application to studying the genetic architecture of exploration behaviour.

High-density SNP microarrays ("SNP chips") are a rapid, accurate and efficient method for genotyping several hundred thousand polymorphisms in large numbers of individuals. While SNP chips are routinely used in human genetics and in animal and plant breeding, they are less widely used in evolutionary and ecological research. In this article, we describe the development and application of a high-density Affymetrix Axiom chip with around 500,000 SNPs, designed to perform genomics studies of great tit (Parus major) populations. We demonstrate that the per-SNP genotype error rate is well below 1% and that the chip can also be used to identify structural or copy number variation. The chip is used to explore the genetic architecture of exploration behaviour (EB), a personality trait that has been widely studied in great tits and other species. No SNPs reached genomewide significance, including at DRD4, a candidate gene. However, EB is heritable and appears to have a polygenic architecture. Researchers developing similar SNP chips may note: (i) SNPs previously typed on alternative platforms are more likely to be converted to working assays; (ii) detecting SNPs by more than one pipeline, and in independent data sets, ensures a high proportion of working assays; (iii) allele frequency ascertainment bias is minimized by performing SNP discovery in individuals from multiple populations; and (iv) samples with the lowest call rates tend to also have the greatest genotyping error rates.

Individual personalities predict social behaviour in wild networks of great tits (Parus major).

Social environments have an important effect on a range of ecological processes, and form a crucial component of selection. However, little is known of the link between personality, social behaviour and population structure. We combine a well-understood personality trait with large-scale social networks in wild songbirds, and show that personality underpins multiple aspects of social organisation. First, we demonstrate a relationship between network centrality and personality with 'proactive' (fast-exploring) individuals associating weakly with greater numbers of conspecifics and moving between flocks. Second, temporal stability of associations relates to personality: 'reactive' (slow-exploring) birds form synergistically stable relationships. Finally, we show that personality influences social structure, with males non-randomly distributed across groups. These results provide strong evidence that songbirds follow alternative social strategies related to personality. This has implications not only for the causes of social network structure but also for the strength and direction of selection on personality in natural populations.

Personality predicts individual responsiveness to the risks of starvation and predation.

Theory suggests that individual personality is tightly linked to individual life histories and to environmental variation. The reactive-proactive axis, for example, is thought to reflect whether individuals prioritize productivity or survival, mutually exclusive options that can be caused by conflicts between foraging and anti-predation behaviour. Evidence for this trade-off hypothesis, however, is limited. Here, we tested experimentally whether exploration behaviour (EB), an assay of proactivity, could explain how great tits (Parus major) respond to changes in starvation and predation risk. Individuals were presented with two feeders, holding good or poor quality food, which interchanged between safe and dangerous positions 10 m apart, across two 24 h treatments. Starvation risk was assumed to be highest in the morning and lowest in the afternoon. The proportion of time spent feeding on good quality food (PTG) rather than poor quality food was repeatable within treatments, but individuals varied in how PTG changed with respect to predation- and starvation-risk across treatments. This individual plasticity variation in foraging behaviour was linked to EB, as predicted by the reactive-proactive axis, but only among individuals in dominant social classes. Our results support the trade-off hypothesis at the level of individuals in a wild population, and suggest that fine-scale temporal and spatial variation may play important roles in the evolution of personality.

Escala de coma de Glasgow pediátrica modificada para cães / Pediatric Glasgow coma scale modified for dogs

Com o objetivo de modificar a escala de coma de Glasgow pediátrica para utilização na medicina veterinária, foram utilizados 30 cães adultos com alterações neurológicas passíveis de avaliação da consciência. A escala modificada para cães foi aplicada em três momentos com intervalos de 48 horas entre eles, resultando em 90 eventos diversos. A escala foi aplicada para avaliação da abertura ocular (AO), da melhor resposta associada à vocalização (MRV) e da melhor resposta motora (MRM). Com a análise fatorial para os indicadores AO, MRV e MRM, obtiveram-se valores iniciais de 2,482, 0,302 e 0,215, respectivamente. A variância foi de 82,7 por cento, 10,1 por cento e 7,2 por cento, respectivamente, e cumulativa de 82,7 por cento, 92,8 por cento e 100 por cento, respectivamente. A extração esperada do principal fator, AO, foi de 2,482 com variância de 82,7 por cento e cumulativa de 82,7 por cento. O resultado da avaliação da consciência dos cães foi normal em 10 por cento dos animais, alteração leve em 20 por cento, moderada em 45 por cento e grave em 25 por cento, com escores de Glasgow iguais a 15, entre 13 e 14, entre 9 e 12 e entre 8 e 3, respectivamente. A escala de coma de Glasgow pediátrica modificada para cães é ferramenta segura para avaliação da consciência de cães adultos.

The pediatric Glasgow coma scale was modified for use in veterinary medicine. Thirty adult dogs with neurological alterations susceptible to evaluation of the conscience were studied. The modified scale for dogs was applied at three moments with intervals of 48 hours, resulting in 90 events. The scale was applied for evaluation of the ocular opening (OO), the best answer associated to vocalization (BAV), and the best motor answer (BMA). With the factorial analysis for the indicators OO, BAV, and BMA the initial values of 2.482, 0.302, and 0.215, respectively, were obtained. The variance was of 82.7 percent, 10.1 percent, and 7.2 percent, respectively, and cumulative of 82.7 percent, 92.8 percent, and 100 percent, respectively. The expected extraction of the main factor, OO, was 2.482 with variance of 82.7 percent and cumulative of 82.7 percent. The evaluation result of the conscience was normal in 10 percent of the animals, light alteration in 20 percent, moderate in 45 percent, and severe in 25 percent, with scores of Glasgow equal to 15, from 13 to 14, nine to 12, and eight to three, respectively. The pediatric Glasgow coma scale modified for dogs was a safe tool for evaluation of the conscience of adult dogs.