The animal on the cover of SQL in a Nutshell, Third Edition, is a chameleon.
There are approximately 85 species of chameleons existing in the world today.
They are mostly indigenous to Africa, although there are a few species found in
Asia and in Europe. Most are tree dwellers. The chameleon is relatively small; the
average adult size is between 6 and 12 inches. It lives mostly on insects and uses
its long tongue to capture its prey. Indeed, the tongue is a critical tool. It can
stretch up to 1.5 times the lizard’s body length, and there is an adhesive pad on
the end on which the insects are trapped. There are several other characteristics
common to all species of chameleons. For example, its eyes are large and
protruding, and the lizard can see 360 degrees without moving its head or body.
Its toes are on either side of its feet, usually three on one side and two on the
other. This is ideal for moving quickly and efficiently through tree branches.
Chameleons are best known for their ability to change their appearance to adapt
to their physical environment. Actually, several types of reptiles can change their
skin color, but the chameleon is far and away the most accomplished. This skill,
which is moderated by the nervous system, obviously is invaluable for hunting
prey and avoiding predators, and also helps to stabilize body temperature. The
extent of this camouflage capability is related to the gender, age, and species of