The long-distance migrant red knot (Calidris canutus ssp. rufa) makes one of the longest yearly migrations of any bird. This subspecies is sharply declining, with a major mortality event following 2000. Here, for a major wintering site in Argentina, food abundance, diet and intake rates were compared in 1995, 2000 and 2008. Intake rate in 2008 was dramatically reduced. Results indicate that during the strongly enhanced winter mortality in 2000 knots faced ecological problems in a stop-over site in USA but did not yet in their southernmost wintering area. However, in 2008 the ecological conditions were such in Argentina that they would have facilitated a further decline, emphasizing the importance of a hemispheric approach to research and management. informacion[at]ebd.csic.es: Escudero et al (2012) Foraging conditions ‘at the end of the world’ in the context of long-distance migration and population declines in red knots. Austral Ecol 37: 355–364. DOI 10.1111/j.1442-9993.2011.02283.x

The mechanisms underlying heterozygosity-fitness correlations (HFCs) are subject of intense debates, especially about how important population features such as size or degree of isolation influence HFCs. Here, variation is reported in HFCs between Large and Small populations of a self-compatible shrub occurring within an extremely fragmented landscape. Whereas heterozygosity explained most of the variance in growth rate of seedling families within Large populations, this relationship was absent within Small populations. Results suggest that inbreeding may explain the observed HFCs within Large populations, and that different genetic processes (such as genetic drift and/or selection) could have overridden HFCs within Small populations. Results open new research perspectives on how different genetic processes underlie variation in HFCs under different population contexts. informacion[at]ebd.csic.es: González-Varo et al (2012) Contrasting heterozygosity-fitness correlations between populations of a self-compatible shrub in a fragmented landscape. Genetica. Doi 10.1007/s10709-012-9655-8

The main factors responsible for the assembly of nectar yeast communities were assessed characterizing the physiological abilities of all yeast species forming the pool of potential colonizers for two Spanish flowering plants. Yeasts were most frequent in external sources (air, flower-visiting insects), less so in the proximate floral environment (phylloplane), and least in pollen and nectar. Nectar communities appeared to be considerably impoverished versions of those in insect glossae and phylloplane. Nectar, pollen, and insect yeast assemblages differed in physiological characteristics from those in other substrates. Nectarivorous Metschnikowia were not more resistant than other yeast species to plant secondary compounds and high sugar concentrations typical of nectar, but their higher growth rates may be decisive for their dominance in ephemeral nectar communities. informacion[at]ebd.csic.es: Pozo et al (2012) Nectar yeasts of two southern Spanish plants: The roles of immigration and physiological traits in community assembly. FEMS Microbiology Ecology 80: 281-293. DOI: 10.1111/j.1574-6941.2011.01286.x