02094nas a2200205   4500008004500000020001400045245012500059210006900184260001200253300001200265490000800277520142500285100001601710700002001726700003001746700002501776700002701801700001801828856004201846       2007                        Engldsh    a0019-101900aHabitat-specific effects of a food supplementation experiment on immunocompetence in Eurasian magpie Pica pica nestlings0 aHabitatspecific effects of a food supplementation experiment on   cOctober  a763-7730 v1493 aParasite pressure and nutrition are two of the most important factors affecting the trade-off between nestling growth and immune development. During development, energy and nutrients are often limited, and nestlings should only dedicate differentially more valuable resources to their immune system when the associated benefits are high (i.e. in situations of an increased risk of parasitism). In this study, we manipulated nutritional condition of Eurasian Magpie Pica pica nestlings by providing a food supplement. Additionally, the study area was subdivided into two categories of habitat (irrigated and arid) based on the presence of irrigation canals. Nestling diet composition was more varied in the irrigated compared with in the arid habitat. In addition, nestlings of the irrigated habitat showed a significantly higher infestation of both ectoparasites and blood parasites and a significantly higher cell-mediated immunity, but lower tarsus length compared with nestlings of the arid habitat. Food supplementation to nestlings did not affect tarsus length, but increased nestling cell-mediated immunity in the arid habitat only. Based on the recent demonstrated trade-off between growth and immunocompetence in nestlings, we suggest that differences between habitats in nestling diet and parasite prevalence may have caused different priority rules in the allocation of resources between both fitness traits.
1 ade Neve, L.1 aSoler, Juan, J.1 aRuiz-Rodriguez, Magdalena1 aMartin-Galvez, David1 aPerez-Contreras, Tomas1 aSoler, Manuel  u<Go to ISI>://ZOOREC:ZOOR14406036320 