據(jù)6月5日的《科學(xué)》雜志報(bào)道說(shuō)，當(dāng)一只布谷鳥(niǎo)希望將它自己的一枚蛋偷偷地放入一個(gè)葦鶯的巢中,，這時(shí)葦鶯會(huì)發(fā)動(dòng)一場(chǎng)激烈的抵御行動(dòng),，它們會(huì)成群地攻擊這些寄生的鳥(niǎo),，同時(shí)發(fā)出很響且刺耳的叫聲，并用它們的鳥(niǎo)喙發(fā)出噼啪之聲。
新的研究顯示,，這些葦鶯可通過(guò)觀察它們的鄰居而學(xué)習(xí)這種行為,，但這種過(guò)程是受到生物學(xué)支配的 – 當(dāng)研究人員用一種無(wú)害的假的鸚鵡來(lái)取代布谷鳥(niǎo)的話，則這些葦鶯就不會(huì)學(xué)到這種技能,。 某些鳥(niǎo)的群體發(fā)展出了針對(duì)諸如布谷鳥(niǎo)這類(lèi)托卵寄生鳥(niǎo)的抵御行為,，但這種行為不會(huì)快到成為遺傳學(xué)變化的結(jié)果。 為了對(duì)替代性的解釋進(jìn)行調(diào)查,，英國(guó)的Nicholas Davies 和Justin Welbergen設(shè)計(jì)了這樣的實(shí)驗(yàn)：在這些實(shí)驗(yàn)中,，他們讓幼小且沒(méi)有經(jīng)驗(yàn)的葦鶯觀察它們的鄰居的針對(duì)布谷鳥(niǎo)和假鸚鵡的行為。 這些天真的葦鶯在觀察了它們的鄰居之后會(huì)采取群攻的行為來(lái)抵擋布谷鳥(niǎo),，但卻不會(huì)抵擋鸚鵡,，這表明，這些葦鶯已經(jīng)具有學(xué)習(xí)新的行為的基礎(chǔ),，并只會(huì)對(duì)真正的威脅進(jìn)行抵抗,。 這種特質(zhì)從長(zhǎng)遠(yuǎn)看會(huì)對(duì)葦鶯的群體有好處，因?yàn)橄袢汗ミ@樣的行為如果應(yīng)用在錯(cuò)誤的情況下則會(huì)產(chǎn)生反效果,，例如,，會(huì)吸引捕食者前來(lái)。（生物谷Bioon.com）
生物谷推薦原始出處：
Science 5 June 2009:DOI: 10.1126/science.1172227
Social Transmission of a Host Defense Against Cuckoo Parasitism
Nicholas B. Davies*, and Justin A. Welbergen
Coevolutionary arms races between brood parasites and hosts involve genetic adaptations and counter-adaptations. However, hosts sometimes acquire defenses too rapidly to reflect genetic change. Our field experiments show that observation of cuckoo (Cuculus canorus) mobbing by neighbors on adjacent territories induced reed warblers (Acrocephalus scirpaceus) to increase the mobbing of cuckoos but not of parrots (a harmless control) on their own territory. In contrast, observation of neighbors mobbing parrots had no effect on reed warblers’ responses to either cuckoos or parrots. These results indicate that social learning provides a mechanism by which hosts rapidly increase their nest defense against brood parasites. Such enemy-specific social transmission enables hosts to track fine-scale spatiotemporal variation in parasitism and may influence the coevolutionary trajectories and population dynamics of brood parasites and hosts.
Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK.
