Provenance does matter: Links between winter trophic segregation and the migratory origins of European robins

Amongst migratory species, it is common to find individuals from different populations or geographical origins sharing staging or wintering areas. Given their differing life histories, ecological theory would predict that the different groups of individuals should exhibit some level of niche segregation. This has rarely been investigated because of the difficulty in assigning migrating individuals to breeding areas. Here, we start by documenting a broad geographical gradient of hydrogen isotopes (δ (2)H) in robin Erithacus rubecula feathers across Europe. We then use δ (2)H, as well as wing-tip shape, as surrogates for broad migratory origin of birds wintering in Iberia, to investigate the ecological segregation of populations. Wintering robins of different sexes, ages and body sizes are known to segregate between habitats in Iberia. This has been attributed to the despotic exclusion of inferior competitors from the best patches by dominant individuals. We find no segregation between habitats in relation to δ (2)H in feathers, or to wing-tip shape, which suggests that no major asymmetries in competitive ability exist between migrant robins of different origins. Trophic level (inferred from nitrogen isotopes in blood) correlated both with δ (2)H in feathers and with wing-tip shape, showing that individuals from different geographic origins display a degree of ecological segregation in shared winter quarters. Isotopic mixing models indicate that wintering birds originating from more northerly populations consume more invertebrates. Our multi-scale study suggests that trophic-niche segregation may result from specializations (arising in the population-specific breeding areas) that are transported by the migrants into the shared wintering grounds.

Young people's well-being and the economic crisis: How does parental unemployment and family wealth affect the downturn experience?

Background: Portugal is among the European countriesmost severely hit by the economic recession and the fifth with the highest unemployment rate. Given that adolescents' development is highly influenced by their living contexts, monitoring the repercussions of the economic recession is essential for the evaluation and improvement of their current and future public health. Objective: To investigate youth perceived repercussions of the economic recession, its association with life satisfaction, as well as to assess differences across parental employment status and family perceived wealth. Methods: Data were drawn from the Portuguese 2014 Health Behaviour in School-aged children survey, aWHO collaborative cross-national study, with a nationally representative sample of 2748 students (Mage = 14.7 years ± 1.2; 48% boys). Descriptive statistics and linear regression models were performed. Results: Levels of life satisfaction are lower when young people perceive that the economic recession generated negative lifestyle changes. Having unemployed parents was found to be significantly associated with perceiving such repercussions and family wealth to decrease the perception of repercussions of the recession. Conclusions: Findings enhance our understanding of how Portuguese youth are being affected by the socioeconomic conditions surrounding them. Such information contributes to improve future research and also allow some considerations about the policies aimed at protecting young people'swellbeing during a period of high unemployment and socioeconomic downturn.