From the animal house to the field : are there consistent individual differences in immunological profile in wild populations of field voles (Microtus agrestis)?

Inbred mouse strains, living in simple laboratory environments far removed from nature, have been shown to vary consistently in their immune response. However, wildlife populations are typically outbreeding and face a multiplicity of challenges, parasitological and otherwise. In this study we seek evidence of consistent difference in immunological profile amongst individuals in the wild. We apply a novel method in this context, using longitudinal (repeated capture) data from natural populations of field voles, Microtus agrestis, on a range of life history and infection metrics, and on gene expression levels. We focus on three immune genes, IFN-γ, Gata3, and IL-10, representing respectively the Th1, Th2 and regulatory elements of the immune response. Our results show that there was clear evidence of consistent differences between individuals in their typical level of expression of at least one immune gene, and at most all three immune genes, after other measured sources of variation had been taken into account. Furthermore, individuals that responded to changing circumstances by increasing expression levels of Gata3 had a correlated increase in expression levels of IFN-γ. Our work stresses the importance of acknowledging immunological variation amongst individuals in studies of parasitological and infectious disease risk in wildlife populations

Conspicuous Female Ornamentation and Tests of Male Mate Preference in Threespine Sticklebacks (Gasterosteus aculeatus)

Sexual selection drives the evolution of exaggerated male ornaments in many animal species. Female ornamentation is now acknowledged also to be common but is generally less well understood. One example is the recently documented red female throat coloration in some threespine stickleback (Gasterosteus aculeatus) populations. Although female sticklebacks often exhibit a preference for red male throat coloration, the possibility of sexual selection on female coloration has been little studied. Using sequential and simultaneous mate choice trials, we examined male mate preferences for female throat color, as well as pelvic spine color and standard length, using wild-captured threespine sticklebacks from the Little Campbell River, British Columbia. In a multivariate analysis, we found no evidence for a population-level mate preference in males, suggesting the absence of directional sexual selection on these traits arising from male mate choice. Significant variation was detected among males in their preference functions, but this appeared to arise from differences in their mean responsiveness across mating trials and not from variation in the strength (i.e., slope) of their preference, suggesting the absence of individual-level preferences as well. When presented with conspecific intruder males, male response decreased as intruder red throat coloration increased, suggesting that males can discriminate color and other aspects of phenotype in our experiment and that males may use these traits in intrasexual interactions. The results presented here are the first to explicitly address male preference for female throat color in threespine sticklebacks.Open Access Publishing Fun

Sex-specific effects of the local social environment on juvenile post-fledging dispersal in great tits

An individual’s decision to disperse from the natal habitat can affect its future fitness prospects. Especially in species with sex-biased dispersal, we expect the cost–benefit balance for dispersal to vary according to the social environment (e.g., local sex ratio and density). However, little is known about the social factors affecting dispersal decisions and about the temporal and spatial patterns of the dispersal process. In our study, we investigated experimentally the effects of the social environment on post-fledging dispersal of juvenile great tits by simultaneously manipulating the density and sex ratio of fledglings within forest plots. We expected young females in the post-fledging period mainly to compete for resources related to food and, as they are subordinate to males, we predicted higher female dispersal from male-biased plots. Juvenile males compete for vacant territories already in late summer and autumn; thus, we predicted increased male dispersal from high density and male-biased plots. We found that juvenile females had a higher probability to leave male-biased plots and had dispersed further from male-biased plots in the later post-fledging phase when juvenile males start to become territorial and more aggressive. Juvenile males were least likely to leave male-biased plots and had smallest dispersal distances from female-biased plots early after fledging. The results suggest that the social environment differentially affected the costs and benefits of philopatry for male and female juveniles. The local sex ratio of individuals is thus an important social trait to be considered for understanding sex-specific dispersal processes

Feeding Behaviour, Swimming Activity and Boldness Explain Variation in Feed Intake and Growth of Sole (Solea solea) Reared in Captivity

The major economic constraint for culturing sole (Solea solea) is its slow and variable growth. The objective was to study the relationship between feed intake/efficiency, growth, and (non-) feeding behaviour of sole. Sixteen juveniles with an average (SD) growth of 2.7 (1.9) g/kg0.8/d were selected on their growth during a 4-week period in which they were housed communally with 84 other fish. Selected fish were housed individually during a second 4-week period to measure individual feed intake, growth, and behaviour. Fish were hand-fed three times a day during the dark phase of the day until apparent satiation. During six different days, behaviour was recorded twice daily during 3 minutes by direct observations. Total swimming activity, frequency of burying and of escapes were recorded. At the beginning and end of the growth period, two sequential behavioural tests were performed: “Novel Environment” and “Light Avoidance”. Fish housed individually still exhibited pronounced variation in feed intake (CV = 23%), growth (CV = 25%) and behavior (CV = 100%). Differences in feed intake account for 79% of the observed individual differences in growth of sole. Fish with higher variation in feed intake between days and between meals within days had significantly a lower total feed intake (r = −0.65 and r = −0.77) and growth. Active fish showed significantly higher feed intake (r = 0.66) and growth (r = 0.58). Boldness during both challenge tests was related to fast growth: (1) fish which reacted with a lower latency time to swim in a novel environment had significantly higher feed intake (r = −0.55) and growth (r = −0.66); (2) fish escaping during the light avoidance test tended to show higher feed intake (P<0.1) and had higher growth (P<0.05). In conclusion, feeding consistency, swimming activity in the tank, and boldness during behavioral tests are related to feed intake and growth of sole in captivity

Future directions in personality, occupational and medical selection: myths, misunderstandings, measurement, and suggestions

This paper has two objectives: (1) presenting recent advances in the personality field concerning the conceptualization of personality arising from the dynamic interactions of behaviour, biology, context, and states, and (2) discussing the implications of these developments for medical selection. We start by presenting evidence that traits are not longer regarded as deterministic and stable. Instead, they are found to change across generations, the life span, and in response to environmental contingencies. Next, drawing on recent research (behavioural reaction norms and the density distribution model) we posit how the expression of trait relevant behaviour changes depending on the situation, such that personality reflects both stability and plasticity across situations. Thus there is an urgent need to explore how traits change as function of medical education. Third, we demystify that some traits are better than others showing that so-called “good” traits have a dark-side. Fourth, we show how these developments impact on how personality might be assessed, thereby presenting recent evidence on the use of contextualized personality measures, Situational Judgment Tests, other reports, and implicit measures. Throughout the paper, we outline the key implications of these developments for medical selection practices

The attendance at preventive health checks around lifestyle. Participation among Dutch people and reasons for non-response

Ongeveer 45% van de 40- tot 75-jarigen neemt deel aan preventief gezondheidsonderzoek als zij hiervoor persoonlijk in een brief worden uitgenodigd. De opkomst is het hoogst bij de 60- tot 70-jarigen. Als voornaamste redenen om zich niet preventief te laten onderzoeken, noemen niet-deelnemers dat ze al regelmatig medisch gecontroleerd worden (dit wordt vaker genoemd in de oudere leeftijdsgroep) of geen interesse of tijd hebben (dit wordt vaker genoemd in de jongere leeftijdsgroep). Dit blijkt uit een onderzoek naar deelname aan twee recente grootschalige Nederlandse projecten, namelijk het Preventief Gezondheidsonderzoek voor Ouderen (PGO-O), uitgevoerd in Zeeland en Amersfoort/Soest, en de Groningen Overweight And Lifestyle studie (GOAL), uitgevoerd in Groningen, Friesland en Drenthe. In deze projecten werden respectievelijk 1779 60 tot 75-jarigen en en 5738 40 tot 70-jarigen uitgenodigd. De bevindingen worden in grote lijnen bevestigd door soortgelijk recent Nederlands onderzoek en een literatuurstudie naar vijftien vergelijkbare internationale onderzoeken. Mensen met het laagste opleidingsniveau lijken minder geneigd om deel te nemen aan preventief gezondheidsonderzoek. Er waren geen duidelijke aanwijzingen voor een selectieve opkomst naar risicofactoren of leefstijl. Veel deelnemers zouden baat kunnen hebben bij een vervolgaanbod van leefstijlbegeleiding. Er werd bijvoorbeeld een grote groep bereikt met hoge bloeddruk en/of obesitas, wat een weerspiegeling lijkt van het vaak voorkomen van deze risicofactoren in de bevolking. Informatie over het mogelijke bereik van preventief gezondheidsonderzoek biedt het beleid en de lokale organisaties concrete handvatten, bijvoorbeeld bij het plannen van de inzet van personeel, de kosten, en de potentiele effecten van preventief gezondheidsonderzoek op populatieniveau.About 45% of the 40- to 75-year-old Dutch population participates in preventive health checks when they are personally invited via an invitation letter. The attendance rate is highest for those aged 60 to 70. As the most important reasons to decline a preventive health check, non-participants mention that they already are under regular medical supervision (mostly in the older age group) or have no interest or time (mostly mentioned in the younger age groups). These are the results of a study on participation in two recent large Dutch projects, the Preventive Health Checks for the Elderly (PGO-O), carried out in the province of Zeeland and the towns Amersfoort/Soest, and the Groningen Overweight And Lifestyle study (GOAL), carried out in the provinces of Groningen, Friesland and Drenthe. In these projects 1179 persons aged 60 to 75 and 5738 persons aged 40 to 70 were invited. The findings are largely confirmed by published data from similar recent Dutch projects and a literature study on fifteen comparable international studies. Persons with the lowest educational level seem to be less likely to participate in preventive health checks. No clear indication existed for selective response according to lifestyle or risk factors. Many participants could benefit from further lifestyle counselling. A high percentage of persons had an elevated blood pressure and/or obesity, probably because of the high prevalence of these risk factors in the general population. Information about the possible reach of preventive health checks are useful for policy makers and local organizations, e.g., in the planning of manpower, the costs, and the potential effects of health checks on a population level.VW

Personality Consistency in Dogs: A Meta-Analysis

Jamie L. Fratkin is with UT Austin; David L. Sinn is with UT Austin and University of Tasmania; Samuel D. Gosling is with UT Austin; Erika A. Patall is with UT Austin.Personality, or consistent individual differences in behavior, is well established in studies of dogs. Such consistency implies predictability of behavior, but some recent research suggests that predictability cannot be assumed. In addition, anecdotally, many dog experts believe that ‘puppy tests’ measuring behavior during the first year of a dog's life are not accurate indicators of subsequent adult behavior. Personality consistency in dogs is an important aspect of human-dog relationships (e.g., when selecting dogs suitable for substance-detection work or placement in a family). Here we perform the first comprehensive meta-analysis of studies reporting estimates of temporal consistency of dog personality. A thorough literature search identified 31 studies suitable for inclusion in our meta-analysis. Overall, we found evidence to suggest substantial consistency (r = 0.43). Furthermore, personality consistency was higher in older dogs, when behavioral assessment intervals were shorter, and when the measurement tool was exactly the same in both assessments. In puppies, aggression and submissiveness were the most consistent dimensions, while responsiveness to training, fearfulness, and sociability were the least consistent dimensions. In adult dogs, there were no dimension-based differences in consistency. There was no difference in personality consistency in dogs tested first as puppies and later as adults (e.g., ‘puppy tests’) versus dogs tested first as puppies and later again as puppies. Finally, there were no differences in consistency between working versus non-working dogs, between behavioral codings versus behavioral ratings, and between aggregate versus single measures. Implications for theory, practice, and future research are discussed.Funding provided by the US Department of Homeland Security, Contract HSHQDC-10-C-00085. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Psycholog