Spleen volume varies with colony size and parasite load in a colonial bird
Spleen volume varies with colony size and parasite load in a colonial bird
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DOI：
10.1098/rspb.2002.2036
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发表时间：
2002-07-07
影响因子：
4.7
通讯作者：
Brown, MB
中科院分区：
文献类型：
--
作者：
Brown, CR;Brown, MB
不同鸟类之间的比较表明，那些暴露于寄生虫和病原体的鸟类在免疫防御方面投入更多，这是通过脾脏大小来衡量的。研究了北美雀形目鸟类岩燕（Petrochelidon pyrrhonota）脾脏体积随种群大小、寄生虫载量和个体种群大小的变化规律。我们使用了1700多只鸟的样本，这些鸟都在1996年的一段恶劣天气中死亡。我们在实验中通过在恶劣天气前对一些蚁群的巢进行熏蒸来控制体外寄生。来自无寄生虫群落的鸟类脾脏明显小于来自自然侵染地区的鸟类；脾脏体积无性别差异，也不随年龄变化。在1996年和1995年恶劣天气前，脾脏平均体积随菌落大小的增加而显著增加，这两种菌落大小都是一个地点体外寄生的指标。个体的繁殖史-群体大小（定义为1996年之前的平均群体大小）与脾脏大小无关。当鸟类暴露于大量体外寄生虫时，结果与寄生虫诱导的脾肿大一致。结果不支持脾脏大小是个体之间免疫防御的不同生活史投资的信号，因此与最近的跨物种比较的解释背道而驰。
Comparisons across bird species have indicated that those more exposed to parasites and pathogens invest more in immunological defence, as measured by spleen size. We investigated how spleen volume varied with colony size, parasite load and an individual's colony-size history in the cliff swallow, Petrochelidon pyrrhonota, a colonial passerine bird of North America. We used a sample of over 1700 birds that had all died during a period of inclement weather in 1996. We experimentally manipulated ectoparasitism by fumigating nests in some colonies prior to the bad weather. Birds from parasite-free colonies had significantly smaller spleens than those from naturally infested sites; spleen volume did not differ between the sexes and did not vary with age. Mean spleen volume increased significantly with the colony size at a site prior to the bad weather in 1996 and at the site in 1995, both measures of colony size being indices of ectoparasitism at a site. An individual's history of breeding-colony size (defined as the average colony size it had occupied in years prior to 1996) had no association with its spleen size. The results are consistent with parasite-induced splenomegaly whenever birds are exposed to large numbers of ectoparasites. The results do not support spleen size as being a signal of differential life-history investment in immunological defence among individuals and thus run counter to interpretations from recent cross-species comparisons.