Every few months this program will feature an animal which has caught the eye of the world's public to become a favorite or "hot" animal. In the first of this unusual series, we will look at the chameleon, one of nature's strangest creatures.
Perhaps no other group of animals has caught mankind's imagination like reptiles. Among the several subclasses (or "orders" in biology) of reptiles are snakes and lizards, turtles and tortoises, crocodiles and alligators, and the tuatara, a marine lizard in New Zealand. The dinosaurs, too, belonged to the class of reptiles. Was it a snake, lizard, or crocodile that caught the fancy of some Chinese in times gone by to create the dragon? A perennial theme, reptiles have been featured over the past ten years in box-office hits and bombs alike as dinosaurs (Jurassic Park and The Lost World), crocodiles, and snakes (Anaconda).Though not nearly as large as these mighty reptiles, the lowly chameleon nonetheless has amazed countless generations with its special talents and skills.
What is a chameleon? Its unusual name fits this unusual animal perfectly, for it translates from the ancient Greek as "lion on the ground." This is unexpected, since chameleons spend most of their time in trees, and as for looking like a lion, a chameleon looks like a...well, a chameleon! No other animal in Nature's zoo looks quite as bizarre as they do. Where do they live? True chameleons are found only in the tropical forests and jungles of the Old World, and nearly half of its species live on the African island of Madagascar.
What's so special about the chameleon? Plenty! From its tongue to its tail the chameleon offers a storehouse of specialities. The tongue of this modern-day dinosaur look-alike can be extended more than twice the length of its body. This type of tongue, also present in frogs and toads, is called an extensile tongue. The eyes of the chameleon are even more remarkable. Its eyes are turreted and can be moved independently so that it can view two different objects simultaneously! This comes in especially handy as it is tree-dwelling. The chameleon can keep one eye on its prey and the other on its footing. Its head is often helmet-shaped, and some species have horn-like structures growing out of this scaly helmet.
The feet and tail of the chameleon are also special. Both are prehensile; that is, they are both perfectly adapted to their sylvan environment. The toes of the chameleon's feet are bunched into inside and outside groups of two or three to enable this reptile to grasp tree branches tightly. The chameleon can thus climb extraordinarily well while using its tail to grab objects for further balance.
The above inventory of natural selection specializations would be remarkable enough, but what really separates the chameleon from its fellow reptiles is the fact that its scales contain the ability to change color. Though many people think the chameleon can change its color at will and that it can blend into any color, these are misconceptions. In fact, chameleons can blend into many natural colors and even patterns, but they cannot do this at will. Instead, this happens naturally according to temperature, emotional state of the animal, and the triggering of certain hormones within its body.
It is hard to imagine an animal more interesting than the chameleon, with its weird appearance and special abilities. We should always remember, however, that these animals require their native habitat to flourish in, not zoos or individuals' terrariums. If you want your grandchildren to see this gift of nature, do not collect it as a pet. These natural treasures evolved over millions of years without mankind's help; they will continue to survive better if left alone.
每隔几个月本节目将专题报道一种受世人瞩目而成为最受喜爱或“热门”的动物。在这个特别系列中,首先我们将介绍大自然中最奇特的生物之一——变色龙。
大概没有其它种类的动物像爬虫类那样引发人类的想象力。在几个亚纲(或生物学的“目”)的爬虫类中,有蛇和蜥蜴、乌龟和陆龟、鳄鱼和短吻鳄以及虫蜥蜴——一种现存于新西兰的海蜥蜴。恐龙也同样属于爬虫类。到底是蛇、蜥蜴还是鳄鱼使远古时代的中国人有所联想而创造出龙的呢?大家对爬虫类这个主题的兴趣一直没有断过,过去10年来以爬虫类为主角拍成的卖座电影和票房极差的电影包括有恐龙的(《侏罗纪公园》和《失落的世界》)、鳄鱼和蛇类的(《大蟒蛇之神出鬼没》)。虽然和这些巨大的爬虫类在体型上相去甚远,低姿态的变色龙仍然以牠特殊的才能和技巧让无数个世代的人感到惊异。
变色龙是什么样的动物呢?它特殊的名字还真符合这只特殊的动物,因为它从古希腊文翻译过来是“地上的狮子”之意。这真叫人意想不到,因为变色龙大部分的时间都在树上,至于说看起来像狮子这点,变色龙看起来就像一只……呃,变色龙!在大自然的动物园里,没有其它动物长得像它们一样古怪。那它们住在哪里呢?真正的变色龙只有在旧世界的热带森林和丛林中才找得到,而几乎有半数的种类住在非洲的马达加斯加岛上。
变色龙有何特别之处呢?那可多了!从舌头到尾巴,变色龙有一大堆特点。这种像是现代恐龙的动物,它的舌头可以伸到比它身体的两倍还要长。这种青蛙和蟾蜍也有的舌头叫做伸缩舌头。变色龙的眼睛则更了不起了。它的眼睛是旋转式的,能够个别转动,如此一来它可以同时注视两个不同的物体!这对它这种住在树上的动物特别有用。变色龙可以一眼盯着牠的猎物,另一眼看着牠立足的地方。它的头形状通常像盔甲,有些种类的变色龙还会从多鳞的甲冑长出角状的结构来呢。
变色龙的脚和尾巴也很特别,二者皆适于抓握;也就是说,二者皆极为适合森林的环境。变色龙的脚趾卷曲成里外两组各两只或三只,使这种爬虫类能够紧抓住树枝;变色龙利用尾巴抓住物体增加平衡因而格外善于攀爬。
上列在物竞天择下发展而成的种种特长实在是了不起,但真正使变色龙不同于其它爬虫类的是它的鳞片拥有变色的能力。虽然很多人以为变色龙可以随意变换颜色,且能够融入任何颜色,但是这些都是错误的观念。事实上,变色龙可以融入许多自然的颜色,甚至形状,但它们却不能随心所欲。相反地,那是根据温度、变色龙的情绪以及它体内某些荷尔蒙机制而自然发生的。
拥有怪异外表和特别能力的变色龙,很难想得出有比它更有趣的动物。然而,我们要时时记住,这些动物需要原居住地来繁衍,而不是动物园或个人的小型饲养园。如果你想让子孙看到这大自然的恩赐,那就不要搜集它来当宠物。这些自然奇珍在没有人类的帮助下演化了数百万年;如果不受打扰的话,它们将更能继续生存下去。