A major question for understanding the ecology of parasite infections and diseases in wildlife populations concerns the transmission pathways among hosts. Network models are increasingly used to model the transmission of infections among hosts – however, few studies have integrated host behaviour and genetic relatedness of the parasites transmitted between hosts. In a study of the Australian sleepy lizard Tiliqua rugosa and its three‐host ixodid tick (Bothriocroton hydrosauri), we asked if patterns of genetic relatedness among ticks were best explained by spatial proximity or the host transmission network. Using synchronous GPS locations of over 50 adult lizards at 10 min intervals across the three‐month activity period, over 2 years, we developed two alternative parasite transmission networks. One alternative was based on the spatial proximity of lizards (at the centre of their home ranges), and the other was based on the frequency of asynchronous shared refuge use between pairs of lizards. In each year, adult ticks were removed from lizards and their genotypes were determined at four polymorphic microsatellite loci. Adult ticks collected from the same host were more related to each other than ticks from different hosts. Similarly, adult ticks collected from different lizards had a higher relatedness if those lizards had a shorter path length connecting them on each of the two networks we explored. The predictors of tick relatedness differed between years. In the first year, the asynchronous shared refuges network was the stronger predictor of tick relatedness, whereas in year two, the spatial proximity‐based network was the stronger predictor of tick relatedness. We speculate on how changing environmental conditions might change the relative importance of alternative processes driving the transmission of parasites.

中文翻译：

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空间邻近性和异步避难所共享网络都解释了蜥蜴之间蜱遗传相关性的模式，但在不同的年份

了解野生动物种群中寄生虫感染和疾病的生态学的一个主要问题涉及宿主之间的传播途径。网络模型越来越多地用于模拟宿主之间的感染传播——然而，很少有研究整合宿主行为和宿主之间传播的寄生虫的遗传相关性。在对澳大利亚瞌睡蜥蜴 Tiliqua rugosa 及其三宿主 ixodid 蜱 (Bothriocroton hydrosauri) 的研究中，我们询问是否可以通过空间邻近性或宿主传输网络来最好地解释蜱之间的遗传相关性模式。在 2 年多的三个月活动期间，每隔 10 分钟使用 50 多只成年蜥蜴的同步 GPS 位置，我们开发了两种替代的寄生虫传输网络。一种选择是基于蜥蜴的空间接近度（在它们的栖息地的中心），另一种是基于成对蜥蜴之间异步共享避难所使用的频率。每年，从蜥蜴中取出成年蜱，并在四个多态性微卫星位点确定它们的基因型。从同一宿主收集的成年蜱比来自不同宿主的蜱更相关。同样，如果这些蜥蜴在我们探索的两个网络中连接它们的路径长度较短，则从不同蜥蜴收集的成年蜱具有更高的相关性。蜱相关性的预测因子因年份而异。在第一年，异步共享避难所网络是蜱相关性的更强预测因子，而在第二年，基于空间邻近性的网络是蜱相关性的更强预测因子。我们推测不断变化的环境条件可能如何改变驱动寄生虫传播的替代过程的相对重要性。