Host-Parasite Interactions and Population Dynamics of Rock Ptarmigan
Host-Parasite Interactions and Population Dynamics of Rock Ptarmigan
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DOI：
10.1371/journal.pone.0165293
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发表时间：
2016-11-21
期刊：
影响因子：
3.7
通讯作者：
Stefansson, Gunnar
中科院分区：
文献类型：
--
作者：
Stenkewitz, Ute;Nielsen, Olafur K.;Stefansson, Gunnar
冰岛的岩雷鸟（Lagopus穆塔）种群数量以多年周期波动，峰值数量为c。每隔10年。我们研究了雷鸟寄生虫群落和寄生虫如何与雷鸟年龄，身体状况和人口密度。从2006年到2012年，我们在冰岛东北部收集了632只松鸡; 630只（99.7%）感染了至少一种寄生虫，616只（98%）感染了外寄生虫，536只（85%）感染了内寄生虫。我们分析了联合寄生虫群落（16种）和已知的致病性寄生虫，两个球虫原虫艾美耳球虫穆塔和艾美耳球虫，两个线虫毛细线虫caudinflata和Trichostrongylus tenuis，一个咀嚼虱Amyrsidea lagopi，和一个皮肤螨Metamicrolichus islandicus指数。总体而言，青少年比成年人有更多的外寄生虫，但内寄生虫水平在两组相似。雷鸟种群密度与体内寄生虫，特别是球虫寄生虫艾美耳球虫穆塔的患病率。这种艾美球虫的年度聚集水平与流行率成反比波动，流行率高峰时低，反之亦然。E.穆塔用1.5年的时间间隔追踪松鸡的种群密度。时间滞后可以解释宿主特异性的艾美球虫，宿主密度依赖的脱落的卵囊，和他们的持久性在环境中从一年到下一个。雷鸟体况与E.穆塔流行率，它们的致病性的指示，这艾美耳球虫也正相关的雷鸟死亡率和略呈负相关的繁殖力。繁殖力和咀嚼虱Amyrsidea lagopi患病率（阴性），过多的青少年死亡率和线虫Capillaria caudinflata患病率（阳性），成年人死亡率和皮肤螨Metamicrolichus islandicus患病率（阴性）之间也有显着的关联。虽然这项研究是相关的，它提供了强有力的证据，E。穆塔通过时间滞后的流行率相对于主机的人口规模和主机的身体状况，死亡率和繁殖力的显着关系可能会破坏雷鸟在冰岛的人口动态。
Populations of rock ptarmigan (Lagopus muta) in Iceland fluctuate in multiannual cycles with peak numbers c. every 10 years. We studied the ptarmigan-parasite community and how parasites relate to ptarmigan age, body condition, and population density. We collected 632 ptarmigan in northeast Iceland in early October from 2006 to 2012; 630 (99.7%) were infected with at least one parasite species, 616 (98%) with ectoparasites, and 536 (85%) with endoparasites. We analysed indices for the combined parasite community (16 species) and known pathogenic parasites, two coccidian protozoans Eimeria muta and Eimeria rjupa, two nematodes Capillaria caudinflata and Trichostrongylus tenuis, one chewing louse Amyrsidea lagopi, and one skin mite Metamicrolichus islandicus. Juveniles overall had more ectoparasites than adults, but endoparasite levels were similar in both groups. Ptarmigan population density was associated with endoparasites, and in particular prevalence of the coccidian parasite Eimeria muta. Annual aggregation level of this eimerid fluctuated inversely with prevalence, with lows at prevalence peak and vice versa. Both prevalence and aggregation of E. muta tracked ptarmigan population density with a 1.5 year time lag. The time lag could be explained by the host specificity of this eimerid, host density dependent shedding of oocysts, and their persistence in the environment from one year to the next. Ptarmigan body condition was negatively associated with E. muta prevalence, an indication of their pathogenicity, and this eimerid was also positively associated with ptarmigan mortality and marginally inversely with fecundity. There were also significant associations between fecundity and chewing louse Amyrsidea lagopi prevalence (negative), excess juvenile mortality and nematode Capillaria caudinflata prevalence (positive), and adult mortality and skin mite Metamicrolichus islandicus prevalence (negative). Though this study is correlational, it provides strong evidence that E. muta through time-lag in prevalence with respect to host population size and by showing significant relations with host body condition, mortality, and fecundity could destabilize ptarmigan population dynamics in Iceland.