What it's like behind the zoo bars; Zucchini, by Barbara Dana. New York: Harper & Row. 122 pp. $10.50. (Ages 8-12 .)

To kindle an awareness of rare and endangered animals while spinning a highly entertaining tale takes a skilled hand, and Barbara Dana manages the task very well in ''Zucchini.''

Zucchini is a rare, black-footed ferret, born at the Bronx Zoo. The big event of his day is when the rodent man drops a carrot into his cage and gives him fresh water. The rest of the time he can walk in circles, back up, take a nap, eat, clean his fur, make up stories, drink his water, or hide inside his log from the people who look into his cage.

Nightly dreams of open places with light, air, different smells, and beautiful colors haunt his waking hours with a vague feeling that there must be more to life than a glass cage.

A desperate dash for freedom propels the little ferret into hair-raising adventures. Along the way he encounters a shy boy named Billy and a caged crow named Arnold, who pines for his old home and friends on Staten Island. He also discovers that love, not travel, brings one home.

This rare story, like E. B. White's ''Stuart Little,'' is for young and old alike. With wisdom, tenderness, and humor, the author has given us a book that leaves us better for having read it.