在自然界中，当年轻的雄蜥蜴向雌蜥蜴寻求交配时，它们经常会遭到其它成年雄蜥蜴的攻击和驱离。为顺利地完成交配，这些年轻的雄蜥蜴有时会改变身体的颜色，让自己看起来更像是一只“雌蜥蜴”，从而麻痹其它雄性蜥蜴并避免遭到攻击。
在最新一期出版的英国《皇家学会学报B》（Proceedings of the Royal Society B）上，澳大利亚国立大学生物学院副教授斯科特·基奥详细介绍了他的这一新发现。斯科特·基奥说，“在这一群体中，成年雄性蜥蜴的颜色极其艳丽，而且它们具有极强的领地意识。而雌性蜥蜴则通常是淡褐色。因此，年轻的雄性蜥蜴只有自觉地改变自己腹部的颜色，这样它们会在性成熟之前看起来仍然像是雌性。”最初，雌性蜥蜴也会允许年轻雄性与之交配，只要不被体型较大的、占有欲强的成年雄性发现，否则这些成年雄性蜥蜴会驱赶和撕咬年轻的对手。这些伪装起来的年轻蜥蜴只有假装成雌性，才能够避免被攻击而拥有繁殖的机会。
斯科特·基奥认为，“如果它们只是改变背部或侧部的颜色，那就很容易被辨认出是雄性，也就根本没有机会靠近雌性。”这种性别伎俩可以让年轻雄性蜥蜴在繁殖季节获得性优势。它们虽然看起来像是雌性，事实上已经是性成熟的雄性。这样他们就可能一整个繁殖季节都会与雌性呆在一起，不过不管它们怎么伪装，它们的气味仍然是雄性的气味。为了验证这一事实，研究人员从野外捕获了一些蜥蜴，并将能够表明它们性别的所有信息素都去除掉。然后把分别带有雄性或雌性气味的雌性和假雌性蜥蜴全部放到典型的成年雄性蜥蜴面前。这些成年蜥蜴会用它们的舌头去品尝这种化学气味，标注为雌性的假雌性立即有所反应，而标注为雄性的假雌性则没有这种反应。因此研究人员认为，雄性蜥蜴会被外表迷惑，但不会被气味迷惑。
此外，研究还发现这些假雌性会刻意与那些爱“嚼舌根”的雄性保持距离，以防止它们的这种秘密泄露出去。其他动物，如鱼类，通常也会采用性别伪装取得性优势。这项研究是首次发现爬行类动物也有这种伎俩，同时该研究最特别之处在于分离了视觉和嗅觉的联系。研究人员还发现，并非是所有年轻雄性蜥蜴都会这种伪装技术。蜥蜴的变色能加很强，特别是避役类蜥蜴以其善于变色获得“变色龙”的美名。变色树蜥在阳光照射的干燥地方通身颜色变浅而头颈部发红，当转入阴湿地方后，红色逐渐消失，通身颜色逐渐变暗。蜥蜴的变色是一种非随意的生理行为变化。它与光照的强弱、温度的改变、动物本身的兴奋程度以及个体的健康状况等有关。（生物谷Bioon.com）
生物谷推荐原始出处：
Proceedings of the Royal Society B February 25, 2009, doi: 10.1098/rspb.2008.1822
Flat lizard female mimics use sexual deception in visual but not chemical signals
Martin J Whiting1,*, Jonathan K Webb2 and J. Scott Keogh3
1 School of Animal, Plant and Environmental Sciences, University of the Witwatersrand Private Bag 3, Wits 2050, Johannesburg, Republic of South Africa
2 School of Biological Sciences, The University of Sydney Sydney, New South Wales 2006, Australia
3 School of Botany and Zoology, The Australian National University Canberra, Australian Capital Territory 0200, Australia
Abstract
Understanding what constrains signalling and maintains signal honesty is a central theme in animal communication. Clear cases of dishonest signalling, and the conditions under which they are used, represent an important avenue for improved understanding of animal communication systems. Female mimicry, when certain males take on the appearance of females, is most commonly a male alternative reproductive tactic that is condition-dependent. A number of adaptive explanations for female mimicry have been proposed including avoiding the costs of aggression, gaining an advantage in combat, sneaking copulations with females on the territories of other males, gaining physiological benefits and minimizing the risk of predation. Previous studies of female mimicry have focused on a single mode of communication, although most animals communicate using multiple signals. Male Augrabies flat lizards adopt alternative reproductive tactics in which some males (she-males) mimic the visual appearance of females. We experimentally tested in a wild population whether she-males are able to mimic females using both visual and chemical signals. We tested chemical recognition in the field by removing scent and relabelling females and she-males with either male or female scent. At a distance, typical males (he-males) could not distinguish she-males from females using visual signals, but during close encounters, he-males correctly determined the gender of she-males using chemical signals. She-males are therefore able to deceive he-males using visual but not chemical signals. To effectively deceive he-males, she-males avoid close contact with he-males during which chemical cues would reveal their deceit. This strategy is probably adaptive, because he-males are aggressive and territorial; by mimicking females, she-males are able to move about freely and gain access to females on the territories of resident males.
