BUSCADOR RECOLECTA

Telomere length of magpie and great spotted cuckoo nestlings Telomere length of magpie and great spotted cuckoo nestlings soon after hatching and before fledging. We also show telomere attrition values and laying-date of each studied nest. Values are means estimates per study nest. data.xlsx, Although little is known on the impact of environment on telomere length dynamics, it has been suggested to be affected by stress, lifestyle and/or life-history strategies of animals. We here compared telomere dynamics in erythrocytes of hatchlings and fledglings of the brood parasite great spotted cuckoos (Clamator glandarius) and of magpies (Pica pica), their main host in Europe. In magpie chicks, telomere length decreased from hatching to fledging while no significant change in telomere length of great spotted cuckoo chicks was found. Moreover, we found interspecific differences in the association between laying date and telomere shortening. Interspecific differences in telomere shortening were interpreted as a consequence of differences in lifestyle and life-history characteristics of magpies and great spotted cuckoos. In comparison with magpies, cuckoos experience reduced sibling competition and higher access to resources, and, consequently, lower stressful environmental conditions during the nestling phase. These characteristics also explain the associations between telomere attrition and environmental conditions (i.e. laying date) for magpies and the absence of association for great spotted cuckoos. These results therefore fit expectations on telomere dynamics derived from interspecific differences in lifestyle and life-history of brood parasites and their bird hosts., Peer reviewed

Black-winged Stilt chicks were captured during the breeding season (from April to August) from 2005-2011 in Doñana rice fields located near the Guadalquivir marshes (37º09N 06º08W, SW Spain), in 2009-2010 in rice fields of Sidi Allal Tazi and in 2009-2011 in rice fields of Larache (both sites in NW Morocco, 34º30N 6º16W and 35º11N 6º07W respectively). Birds were also sampled at natural ponds in the Doñana area in 2010-2011 (37º04N 6º27W), and in natural wetlands at Larache and a coastal lagoon in Briech (NW Morocco, 35º11N 6º07W and 35º31N 6º00W respectively) in 2011., The Junta de Andalucía funded this study through the project “Las aves acuáticas de Doñana y el cultivo del arroz: la interacción entre la agricultura y la conservación de las zonas húmedas”. This study was possible thanks to the INRA administration and CNRST-CSIC collaboration program (P2007MA01 and P2009MA01). GMT was funded by an I3P-CSIC grant for the formation of Researchers. MMH is supported by a Marie Curie Intra-European Fellowship for Career Development (PIEF-GA-2011-299747) within the 7th Framework Programme (FP7 2007-2013) of the European Commission., Peer reviewed