Antiparasitic defenses in hosts of South American cowbirds  

南美牛鹂宿主的反寄生防御行为(英文)

作　　者：Juan Carlos REBOREDA Vanina D.FIORINI María C.DE MaRSICO 

机构地区：[1]阿根廷布宜诺斯艾利斯大学生态,遗传和进化生物学系

出　　处：《Chinese Birds》2013年第1期57-70,共14页中国鸟类（英文版）

基　　金：supported by grants of Agencia Nacional de Promoción Científica y Tecnológica and Universidad de Buenos Aires

摘　　要：The cowbirds (Molothrus, Icteridae) are a monophyletic group that includes five extant brood-parasitic species. The Screaming (M. rufoaxillaris), Giant (M. oryzivorus) and Shiny (M. bonariensis) cowbirds range mostly in South America. Screaming and Shiny cowbirds are the ancestral and most recent species of the clade, respectively, therefore, differing in how long they have coevolved with their hosts. We present new experimental data on egg-rejection in a host of the Shiny Cowbird, the House Wren (Troglodytes aedon), review different lines of antiparasitic defenses in hosts of Screaming, Giant and Shiny cowbirds and assess whether hosts of different parasites differ in the type and extent of defenses. Hosts of all three parasites ejected non-mimetic eggs. Most hosts of Giant and Shiny cowbirds were grasp ejectors, whereas the main host of the Screaming Cowbird (the Baywing, Agelaioides badius) ejected parasitic eggs using its feet. Hosts smaller than Shiny Cowbirds neither ejected cowbird eggs nor deserted nests following parasitism. Some hosts also reacted more aggressively towards the parasite. The main host of Screaming Cowbird discriminated against non-mimetic chicks. Our results show that most hosts, regardless of the presumed evolutionary time of interaction with the parasite, have evolved some type of antiparasitic defense.牛鹂(Molothrus属,拟鹂科)是一个单起源的类群,包括现存的5种寄生性繁殖鸟类。啸声牛鹂(M.rufoaxillaris)、巨牛鹂(M.oryzivorus)和紫辉牛鹂(M.bonariensis)主要分布在南美。其中,啸声牛鹂与紫辉牛鹂分别代表较古老和最近进化的两个支系,因此有着各自不同的与宿主协同进化的历史。本文研究了紫辉牛鹂的宿主莺鹪鹩(Troglodytes aedon)的拒卵行为,同时综述了以上3种牛鹂的不同宿主的反寄生防御行为。3种牛鹂的宿主均能识别和拒绝非模拟的寄生卵,其中巨牛鹂和紫辉牛鹂的大部分宿主用嘴叼卵,而啸声牛鹂的主要宿主栗翅牛鹂(Agelaioides badius)则用脚扔掉寄生卵。比紫辉牛鹂小的宿主,在遭遇寄生时则不扔卵,也不弃巢。有些宿主比另一些宿主种类对寄生的牛鹂更具有攻击行为。啸声牛鹂的宿主还能够识别非模拟的寄生雏鸟。我们的结果说明,尽管与牛鹂协同进化的历史不同,大部分牛鹂的宿主已经进化出不同类型的反寄生防御对策。

关 键 词：brood parasitism COWBIRDS egg rejection Molothrus nest defense 

分 类 号：Q958[生物学—动物学]