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 02410nas a2200193   4500008004100000020001400041245007200055210006900127260001000196300001200206490000800218520186000226653001302086653001102099653002202110100002002132700002202152856004202174       2007                        eng d  a0019-101900aEcological factors influencing disease risk in eagle owls Bubo bubo0 aEcological factors influencing disease risk in eagle owls Bubo b  cApril  a386-3950 v1493 aIn this study we assessed whether local habitat features and host population density influenced disease risk in Eagle Owl Bubo bubo fledglings. Measures of immune defence (concentrations of circulating white blood cells), prevalence of three parasite types (a blood parasite Leucocytozoon ziemanni, an insect Carnus haemapterus, and a tick Rhipicephalus sp.) and total number of parasite species were used to quantify disease risk. We tested the hypotheses that disease risk in fledglings was higher in nests located in areas with higher length of and proximity to watercourses (as a higher abundance and viability of parasites and vectors occur in wetter areas), higher cover of forest (as forest moistness and humidity can favour higher vector and parasite proliferation), higher habitat diversity (as environmental heterogeneity increases the pool of potential vectors and parasites) and higher local owl population density (as disease transmission might be density-dependent). The clearest relationship was with the proximity of freshwater, although the other hypotheses were also partially supported. Concentrations of white blood cells, the number of parasite species and, weakly, the prevalence of Carnus haemapterus were all higher in nests closer to watercourses. The prevalence of blood parasites increased with the cover of forested areas. Fledglings from nests located in more diverse habitats had higher white blood cell concentrations and showed higher prevalence of blood parasites. Finally, local host population density was positively correlated with the prevalence of blood parasites. The results suggest the existence of complex and interrelated links between ecological parameters and three different measures of disease risk, and highlight the importance of immunological approaches to assess disease risk at an intraspecific level.
10aCarnidae10aCarnus10aCarnus hemapterus1 aOrtego, Joaquon1 aEspada, Francisco  u<Go to ISI>://ZOOREC:ZOOR14307044821 