Are chronic avian haemosporidian infections costly in wild birds?
Are chronic avian haemosporidian infections costly in wild birds?
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DOI：
10.1111/j.1600-048x.2011.05281.x
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发表时间：
2011-11-01
影响因子：
1.7
通讯作者：
Bensch, Staffan
中科院分区：
文献类型：
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作者：
Asghar, Muhammad;Hasselquist, Dennis;Bensch, Staffan
在鸟类中常见的一组寄生虫是血孢子虫，它们的健康后果和对生活史特征的影响一直备受争议。在瑞典高丽芦苇林莺的长期研究种群中，以前的研究表明，血孢子虫的血液寄生虫在繁殖季节处于慢性期，感染和未感染的鸟类的健康状况相似。在本研究中，我们量化了1987至1998年间采集的718只成年芦苇的寄生虫密度(寄生虫血症)，以确定三种最常见的寄生虫物种：支原体血凝素(Haemoprous payevskyi，GRW1)、阿什福迪疟原虫(Promium ashfordi，GRW2)和残存疟原虫(Promium relicum，GRW4)。我们验证了Q-PCR方法能够准确地定量Payevskyi血蛋白(GRW1)，因为它与显微镜下看到的寄生虫数量高度相关。根据三种寄生虫谱系的流行率，两个谱系的混合感染频率明显高于预期。三个家系的平均寄生虫血症水平有显着差异，个别禽类的寄生虫血症水平在不同年份之间可重复出现。在所有三种寄生虫谱系的总和中，女性的寄生虫血症倾向于高于男性。具有较高GRW1寄生虫血症的雌性往往在春季较晚到达其繁殖地。GRW1寄生虫血症与羽化后代数呈负相关，GRW2寄生虫血症与招募后代比例呈负相关趋势。总体而言，我们的结果表明，慢性血孢子虫感染对寄主生活史特征有轻微但显著的影响，因此可能是野生鸟类种群的重要选择因素。
One group of commonly found parasites in birds, for which fitness consequences and effects on life history traits have been much debated are Haemosporidian blood parasites. In a long term study population of great reed warblers Acrocephalus arundinaceus in Sweden, previous studies have shown that the Haemosporidian blood parasites are in their chronic phase during the breeding season and that the fitness of infected and non-infected birds are similar. In the present study, we quantified parasite intensity (parasitemia) in 718 adults great reed warblers sampled between 1987 and 1998 for the three most common parasite species; Haemoproteus payevskyi (lineage GRW1), Plasmodium ashfordi (GRW2) and Plasmodium relictum (GRW4). We verified that the q-PCR method is accurately quantifying Haemoproteus payevskyi (GRW1) as it was highly correlated with the number of parasites seen under microscope. Frequency of mixed infections with two lineages was significantly higher than expected based on the prevalence of each of the three parasite lineages. The mean level of parasitemia was significantly different for the three lineages and individual birds had repeatable parasitemia levels between years. Females tended to have a higher parasitemia than males for all three parasite lineages combined. Females with higher GRW1 parasitemia tended to arrive later in spring to their breeding sites. There was a negative correlation between parasitemia and number of fledged offspring for GRW1, and a tendency for a negative correlation between GRW2 parasitemia and the proportion of recruiting offspring. Overall our results demonstrate that chronic Haemosporidian infections can have slight but significant effects on host life history traits, and therefore may act as important selective agents in wild bird populations.