园丁鸟可以模仿多种声音。澳大利亚研究人员研究发现，这一本领可能因为鸟儿紧张。
园丁鸟生活在澳大利亚和新几内亚，一大特征是雄鸟常用草、小枝和色彩艳丽的材料建成大而精致的鸟窝以吸引雌鸟。
除掌握一手筑巢绝技，园丁鸟还“口技”出众，最多可以模仿15种声音。
人们先前认为，这种鸟经常模仿一些猛禽的叫声，以吓退敌人。但澳大利亚迪金大学研究员劳拉·凯莉等学者在昆士兰省中部收录雄性斑点园丁鸟叫声后发现，猛禽叫声在模仿声音中只占20%。
凯莉说，园丁鸟发出的模仿声音中主要是鸟之间争斗时发出的声音，以及受到猛禽或其他威胁时发出的叫声。
园丁鸟甚至能模仿人的声音。凯莉记录到它模仿一个人呼唤一只名叫“邦尼”的猫。
凯莉在最新一期德国《自然科学》（Naturwissenschaften）杂志发表研究报告说，鸣禽学舌现象并不罕见，但对形成这一现象的原因了解得不多。
她认为，栖息环境或许与这一现象相关。斑点园丁鸟模仿的声音大多是鸟处于领地遭侵犯等紧张状态下发出的声音。
“压力已经被证明在很多时候可以提高学习能力和记忆力，”凯莉说，“我们推测园丁鸟初次听到那些声音时处于紧张环境，使它学会那些声音，日后受到压力时会模仿出这种声音。”
凯莉说，一些其他种类的鸟同样可以模仿示警声音，或许同样可以用“高度紧张状态下可以提高学习能力”来解释。
英国剑桥大学研究员汤姆·弗劳尔发现燕卷尾可以模仿其他几种鸟的示警声音，但原因似乎与斑点园丁鸟不同。
这种鸟会跟随猫鼬，当猫鼬找到食物时，燕卷尾就模仿其他鸟发现捕食动物时发出的示警声，好像真的有捕食动物，吓走猫鼬，然后去偷猫鼬留下的食物。
弗劳尔说，为不让猫鼬发觉受骗，燕卷尾时常模仿不同鸟的示警声音，甚至模仿猫鼬的示警声音。
凯莉说，弗劳尔对燕卷尾的研究首次证明鸟可以靠模仿示警声觅食。
她说：“鸣禽中大约20%会模仿声音，但是我们对许多鸟这样做的功能知之甚少。”
她称赞弗劳尔的发现是“拼图中关键一块”。（生物谷Bioon.com）
生物谷推荐原文出处：
Naturwissenschaften DOI： 10.1007/s00114-011-0794-z
Original PaperThe mimetic repertoire of the spotted bowerbird Ptilonorhynchus maculatus
Laura A. Kelley and Susan D. Healy
Although vocal mimicry in songbirds is well documented, little is known about the function of such mimicry. One possibilityis that the mimic produces the vocalisations of predatory or aggressive species to deter potential predators or competitors.Alternatively, these sounds may be learned in error as a result of their acoustic properties such as structural simplicity.We determined the mimetic repertoires of a population of male spotted bowerbirds Ptilonorhynchus maculatus, a species that mimics predatory and aggressive species. Although male mimetic repertoires contained an overabundance ofvocalisations produced by species that were generally aggressive, there was also a marked prevalence of mimicry of soundsthat are associated with alarm such as predator calls, alarm calls and mobbing calls, irrespective of whether the speciesbeing mimicked was aggressive or not. We propose that it may be the alarming context in which these sounds are first heardthat may lead both to their acquisition and to their later reproduction. We suggest that enhanced learning capability duringacute stress may explain vocal mimicry in many species that mimic sounds associated with alarm.
