Fitness in common buzzards at the cross-point of opposite melanin-parasite interactions
Fitness in common buzzards at the cross-point of opposite melanin-parasite interactions
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DOI：
10.1111/j.1365-2435.2008.01460.x
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发表时间：
2008-12-01
影响因子：
5.2
通讯作者：
Krueger, O.
中科院分区：
文献类型：
--
作者：
Chakarov, N.;Boerner, M.;Krueger, O.
黑色素是脊椎动物的主要色素之一，具有许多功能。虽然它被认为具有抗病原体的作用，但它与外寄生虫和体内寄生虫感染的关系在很大程度上仍有待研究。常见的秃鹰Buteo buteo有三种真黑素变体，它们在一生中的繁殖成功率不同。我们研究了分布的吸血体外寄生虫Carnus haemapterus和血液寄生虫Leucocytozoon toddi之间的秃鹰雏鸟和相关的寄生虫感染宿主和父母的形态。我们控制黑色素形态对寄生虫的影响，潜在的混淆总白细胞数，嗜异粒细胞：淋巴细胞比（H：L比），年龄，性别，等级内的育雏和每年的食物availability.血液寄生虫患病率较低的后代的中间色的男性。这种模式是明显的，在高和低的食物供应，虽然这一结果并没有保持在中间田鼠密度，它可能有助于观察到的健身差异在雄性秃鹰。与此相反，肉虫苍蝇得分增加与宿主羽毛的黑暗。但在感染血液寄生虫的雏鸡中，白细胞体的感染强度随着羽色的加深而降低，这两种寄生虫可能对宿主的黑化产生相反方向的选择压力。因此，具有中等黑色素量的秃鹰可能会繁荣，因为它们对体内寄生虫有足够的保护，但对体外寄生虫没有太大的吸引力。寄生虫可以帮助解释在它们的秃鹰宿主中颜色多态性的持久性。
Melanin is one of the major pigments of vertebrates and has many suggested functions. Although it is supposed to have an antipathogenic effect, its relationship to infection with ecto- and endoparasites largely remains to be examined.The common buzzard Buteo buteo occurs in three eumelanin morphs which differ in their lifetime reproductive success. We examined the distribution of the blood-sucking ectoparasite Carnus haemapterus and the blood parasite Leucocytozoon toddi among buzzard nestlings and related parasite infection to the morph of the host and its parents. We controlled the effect of melanin morph on parasites for the potentially confounding total leukocyte numbers, heterophil : lymphocyte ratio (H : L ratio), age, sex, hierarchical rank within the brood and annual food availability.Blood parasite prevalence was lower in offspring of intermediately coloured males. This pattern was apparent during high and low food availability, and although this result did not remain under intermediate vole densities, it could contribute to observed fitness differences in male buzzards. In contrast, carnid fly score increased with darkness of the host plumage. However, among chicks infected with the blood parasite, Leucocytozoon infection intensity decreased with plumage darkness.The two parasite species may exert selection pressures in opposite directions on melanism of their host. Therefore, buzzards with intermediate amounts of melanin may prosper as they are sufficiently protected against endoparasites, but not too attractive for ectoparasites. Parasites could help explain the persistence of colour polymorphism in their buzzard host.