VICKI CONSTANTINE CROKE has been covering pets and wildlife for more than a decade, and writes the "Animal Beat" column for The Boston Globe,"" A former writer and producer for CNN, she has been a contributing reporter for the National Public Radio environment show Living on Earth and consults on film and television projects, most recently a two-hour documentary on gorillas for the A&E channel. Croke is the author of The Modern Ark: The Story of Zoos-Past, Present and Future,"" and has also written for Time, People,"" The Washington Post, Popular Science, Gourmet, National Wildlife, Discover,