Chine Birds 2013,4(1):57–70DOI 10.5122/cbirds.2013.0003
ORIGINA L ARTICLE
3B j F y U y O S y
Received 16December 2012;accepted 16February 2013f (R )@f Antiparasitic defens in host s of South American cowbirds
涨停板Juan C.REb OREd A ,V anina d.FIORINI,Mar ía C.d E M áRsICO白衣送酒
儿童睡觉磨牙Departamento de Ecolog ía,Gen ética y E voluci ón,Facultad de Ciencias E xactas y Naturales,Universidad de Buenos Aires &IEGE BA -CONICET ,Pabell ón II Ciudad Universitaria,C1428EGA Buenos Aires,A rgentina
A bstrac t The cowbirds (Molo thrus,Icteridae)are a monophyletic group that includes ve extant brood-parasitic species.The Screaming (M.ruf oaxillaris),Giant (M.o ryziv orus)and Shiny (M.bonar-iensis)cowbirds range mostly in South America.Screaming and Shiny cowbirds are the ancestral and most recent species of the clade,respectiv ely ,therefore,differing in how long they hav e coev olved with their hosts.We prent new experimental data on egg-rejection in a host of the Shiny Cow-bird,the
Hou Wren (T rog lody tes aedon),review different lines of antiparasitic defens in hosts of Screaming,Giant and Shiny cowbirds and asss whether hosts of different parasites differ in the type and extent of defens.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,A g elaioides badius)ejected parasitic eggs using its feet.Hosts smaller than Shiny Cowbirds neither ejected cowbird eggs nor derted nests following parasitism.Some hosts also reacted more ag gres-sively towards the parasite.The main host of Screaming Cowbird discriminated ag ainst non-mimetic chicks.Our results show that most hosts,regardless of the presumed evolutionary time of interaction with the parasite,have evolv ed some ty pe of antiparasitic defen.
K e ywords brood parasitism,cowbirds,egg rejection,Molothrus,nest defen
Introduct ion新疆高校
烧烤生蚝
Interspeci c avian brood parasites lay their egg s in nests of other species,the hosts,which provide parental care to the parasitic eggs and chicks (Pay ne,1977;Rothstein and Robinson,1998;Davies,2000).Brood parasitism reduces the reproductive success of hosts (Rothstein and Robinson,1998),which lect for the evolution of antiparasitic defens (i.e.,host traits that reduc
终于等到你作文e the impact of parasitism,which have evolv ed in respon to,or are currently maintained by ,lection pressures arising from parasitism;Rothstein,1990;K r üger,2007).In turn,host defens may lect for parasite ’s counter-defens and potentially create a co-evolutionary arms
race (Dawkins and Krebs,1979;Rothstein,1990;Davies,2011).
养兔子怎么养Interspecific avian brood parasitism has evolv ed independently at least ven times in birds (Sorenson and Payne,2002):three times among the cuckoos,once in each of the honey guides and waterfowl,and twice among songbirds:the African brood parasitic nches and the cowbirds.The cowbirds compri a monophy-letic group (Lany on,1992),which is comprid of v e species that vary greatly in the degree of host speci c-ity (Ortega,1998).The basal species of this clade,the Screaming Cowbird (Molothrus rufo axillaris)parated from the lineage leading to other parasitic cowbirds 2.8–3.8My a (Rothstein et al.,2002)and is one of the most specialized brood parasites,using almost exclu-sively the Baywing (Ag elaioides badius)(Friedmann,1929;Fraga,1998;De M ársico et al.,2010a).By contrast,the two most recently derived species of the clade (i.e.,–My ;R ,),S y (M )B (M 201ei ing orestr niversit and C hina rnithologic al oc iet A uthor or correspondenc e Juan C.e boreda E-mail:rebore da ege .cen.uba.ar
应届生自我介绍0.8 1.2a othstein et al.2002the hin Cowbird .bonariensis and the rown-headed Cowbird .
