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Most papers on the physical condition of birds during spring migration focused on food availability preceding migratory take-off. Only a few studies examined the effect of climate conditions at the wintering grounds upon autumn arrival on bird physical condition later on. Here, we hypothesized that environmental conditions upon arrival at the wintering grounds, and not necessarily upon departure, have a crucial carry-over effect on bird spring migration. Using 29,000 observations of the lesser whitethroat, Sylvia curruca, and the eastern Bonelli’s warbler, Phylloscopus orientalis, we found temperatures upon arrival at the African wintering grounds to be the only climatic variable correlated with birds’ body state upon spring stopover in Israel, six months later. Two different mechanisms could explain these results. One possibility is that high temperatures create favorable conditions for insect activity, which allows rapid recovery from autumn migration and hence successful winter survival and maintenance. Another possible scenario is that harsh conditions, due to the heat and dry environment, cause high mortality, permitting survival of larger individuals which, then, enjoy reduced inter- and intra-specific competition. Whatever the mechanism is, our findings suggest that conditions upon autumn arrival, and not necessarily at the end of winter as traditionally thought, may have a major impact on migrating birds. [ABSTRACT FROM AUTHOR]

Migration studies emphasize the role of economic, social and cultural capital in shaping out-migration decisions. Yet, little attention is paid to the effect of capital endowment on return migration, particularly among the highly educated. This article examines the extent to which different forms of capital determine return decisions of early-career researchers (ECRs). We hypothesized that individuals from more privileged backgrounds would repatriate at higher rates, due to the benefits that their capital stock might offer them upon homeland re-integration at home. Drawing on a sample of 223 early career Israeli scholars in STEM (Science, Technology, Engineering and Mathematics) disciplines, we used logistic regressions to analyze the effects of material wealth, social ties, and family-oriented cultural capital on their return propensities. No significant differences were found between repatriating and non-repatriating scholars with respect to cultural capital. However, accumulating social and economic capital was positively correlated with the decision to repatriate as was marrying into academic families. [ABSTRACT FROM AUTHOR]