Modeling the consequence of increased host tolerance toward avian brood parasitism
Modeling the consequence of increased host tolerance toward avian brood parasitism
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DOI：
10.1007/s10144-010-0221-x
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发表时间：
2010
影响因子：
1.7
通讯作者：
F. Takasu;C. Moskát
中科院分区：
文献类型：
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作者：
F. Takasu;C. Moskát
鸟类育雏寄生虫大大降低了其宿主的繁殖成功率。实验研究表明，一些宿主已经进化出了对抗寄生虫的防御能力，比如识别和拒绝与自己卵不同的寄生虫卵的能力。宿主如何识别寄生的详细机制仍然未知，但最近的研究表明，在许多情况下，宿主的识别是基于窝卵的不一致性，并且当巢被多重寄生时，宿主更容易出错，即，寄主更倾向于接受多重寄生而不是单一寄生。在匈牙利的一个地区，大苇莺（Acrocephalus arundinaceus）是普通杜鹃（Cuculus canorus）的主要寄主之一，寄生严重，寄生率几十年来一直保持在相当高的水平。以前的数学模型表明，这样一个高的寄生率可以保持，因为焦点主机人口的行为作为一个水槽，很少的主机可以复制，但移民从外面弥补了主机在水槽人口的繁殖损失。在这里，我们探讨的后果，增加主机对多重寄生的耐受性，这在以前的研究中被忽视，使用一个简单的模型。我们的模型分析表明，寄主耐受性的提高可以显着地有助于寄生虫丰度和寄生率保持在一个高水平。我们认为，这样的主机行为，结合主机移民，可以是一个重要的因素，负责观察到的严重寄生。
Avian brood parasites greatly reduce the reproductive success of their hosts. Empirical studies have demonstrated that some hosts have evolved defenses against parasitism like an ability to recognize and reject parasitic eggs that are dissimilar to their own eggs. Detailed mechanisms of how hosts recognize parasitism still remain unknown, but recent studies have shown that the host’s recognition, in many cases, is based on discordance of the eggs in a clutch, and that hosts are more error-prone when the nest is multiply parasitized, i.e., hosts tend to accept more multiple parasitism than single parasitism. In an area in Hungary, the great reed warblerAcrocephalus arundinaceus, one of the main hosts of the common cuckooCuculus canorus, is heavily parasitized and the parasitism rate has been kept at quite a high level for decades. Previous mathematical models suggest that such a high parasitism rate can be maintained because the focal host population behaves as a sink where few hosts can reproduce but immigration from outside replenishes the loss of host reproduction in the sink population. Here, we explore the consequences of the increased host tolerance towards multiple parasitism which has been overlooked in the previous studies using a simple model. Our model analysis shows that the increased host tolerance can dramatically contribute to both the parasite abundance and the parasitism rate being kept at a high level. We suggest that such a host behavior, combined with host immigration, can be an important factor responsible for the observed severe parasitism.