Tella J L, Blanco G, Forero M G, Gajón A, Donázar J A, Hiraldo F
Department of Biology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada S7N 5E2.
Proc Natl Acad Sci U S A. 1999 Feb 16;96(4):1785-9. doi: 10.1073/pnas.96.4.1785.
The factors explaining interspecific differences in prevalences of blood parasites in birds are poorly known. We simultaneously assessed 20 social, ecological, life history, and sampling-related variables that could influence hemoparasite prevalences among diurnal birds of prey in Spain. Our results show that multiple factors are responsible for the studied host-parasite association. We confirmed for the first time that prevalence is inversely correlated to the embryonic development period, and thus probably to immune performance, even among closely related birds. Macrohabitat features related to vector availability are also important, prevalences being higher in species breeding in forested habitats. Finally, prevalence is positively correlated with the host's world geographic range. We hypothesize that larger geographic ranges offered more opportunities for host-vector-hemoparasite associations to become established. The results from our multivariate analyses differ from those obtained through univariate ones, showing that all potential factors should be assessed jointly when testing any ecological or evolutionary hypothesis dealing with parasites.
目前对于解释鸟类血液寄生虫患病率种间差异的因素知之甚少。我们同时评估了20个可能影响西班牙昼行性猛禽血液寄生虫患病率的社会、生态、生活史和采样相关变量。我们的结果表明，多种因素导致了所研究的宿主 - 寄生虫关联。我们首次证实，患病率与胚胎发育时期呈负相关，因此可能与免疫性能也呈负相关，即使在亲缘关系密切的鸟类中也是如此。与媒介可利用性相关的宏观栖息地特征也很重要，在森林栖息地繁殖的物种中患病率更高。最后，患病率与宿主的世界地理分布范围呈正相关。我们推测，更大的地理分布范围为宿主 - 媒介 - 血液寄生虫关联的建立提供了更多机会。我们多变量分析的结果与单变量分析的结果不同，这表明在检验任何与寄生虫相关的生态或进化假设时，应综合评估所有潜在因素。
