''Wow! Did you know that a blue whale can weigh more than 16 elephants?'' my 11-year-old daughter exclaimed. Two minutes later: ''Mom, did you know that the biggest bird's eggs ever laid were as big as breadboxes?'' Not only was she impressed, she was obviously enjoying what she was reading - Owl's Question and Answer Book No. 1 (Golden Press, New York. 45 pp. $6.95). This, and its companion volume, Owl's Question and Answer Book No. 2, are delightful compilations of the questions the editors of ''Owl Magazine'' (a book published by Canada's Young Naturalist Foundation) are most frequently asked. The result is an intriguing potpourri of information about our world and ourselves.
Why don't birds fall off branches when they sleep? Why do your fingers shrivel when you take a bath? Where does the water go when the tide goes out? The answers to these and many other questions are given clearly and in terms the 9- to 12-year-old can easily comprehend. Though the concise index is useful for finding answers to specific questions, a serendipitous approach will probably be more fun. It's bound to lead you and your child to fascinating questions you might never have thought to ask.
Both volumes contain an eye-catching combination of color photographs, representational illustrations, and cartoonlike drawings. It was disappointing to find that a few of the photos in one of my copies were printed slightly out of register, resulting in some blurry shapes and muddy colors. With this exception, however, the books are nicely made - you just might want to leaf through your copy in the bookstore before you buy.
Dodd Mead's ''Skylight'' books (New York. 64 pp. $7.95 each) form an excellent informative series on a wide array of animals. These books are lively , well-researched, and make fascinating reading. The black and white photographs which amply illustrate this series are somewhat uneven in quality, but this probably won't trouble most of the 7- to 10-year-olds for whom the books are intended.
The three most recent releases in the Skylight series are Orangutans: The Red Apes, by Kay McDearmon; The Strange Armadillo, by Wyatt Blassingame; and Hyenas, by Alice L. Hopf. Of these three, ''Hyenas'' was a standout to me - perhaps because it exploded so many myths about these often unpopular animals. I found it particularly interesting to learn that the studies of Dutch scientist Hans Kruuk revealed that the spotted hyena, commonly thought to be a cowardly scavenger living only off the spoils of other animals, actually makes its own kills. Often it is even chased away from its just desserts (pardon me) by male lions who hear the hyenas eating.
''Orangutans'' (did you know that these animals live in Borneo and Sumatra, not in Africa?) has a pleasant, informative text and some very appealing photographs of apes in captivity.
The adjective ''strange'' in the title of a book about armadillos (''The Strange Armadillo'') is an appropriate one, for these animals are unusual in action as well as in appearance. The author humorously describes how two scientists saw an armadillo cross a pond by simply sinking to the bottom and walking across underwater. Armadillos can also swallow large quantities of air, which causes them to float. Then, using their powerful legs like oars on a rowboat, they paddle to the opposite shore. With a combination of personal observation, anecdote, and research Mr. Blassingame relates the life story of these unusual animals, as well as their use by man in medical research.
Secrets of a Wildlife Watcher, by Jim Arnosky (Lothrop, Lee & Shepard, New York. 64 pp. $9.50), is a sheer delight! From the beauty of its binding to the freshness of its format, this is a book any budding naturalist would love to own.
How to read the clues animals leave as they go about their lives, how to see beyond an animal's camouflage, how to camouflage yourself (including excellent instructions on building a blind), and how to really see what you see - all of these, as well as many intimate details of the lives of particular animals - form the basis of this book. Just as important as the text, however, are the author's clear, skillful pencil sketches which form a frame around the outer edge of every page. This naturalist's-notebook style lends an informal, inviting feel to the book.
''Secrets of a Wildlife Watcher,'' however, is more than just a collection of useful hints and attractive illustrations. It is an ardent attempt to nourish a child's interest in the world around him and is a fitting tribute to Einstein's words quoted in the epigraph: ''Joy in looking and comprehending is nature's most beautiful gift.''