The irrepressible Gibbons (The Honey Makers, p. 141, etc.) returns for a look at a bird that, along with pigeons and sparrows, may be so ubiquitous to some readers that they won't have given gulls much thought. In her brisk, straightforward text, Gibbons covers the herring gulls' markings, habitats, effects on the environment, and nest-building, as well as the hatching and growth of fledglings. The illustrations are all water and sky, showing preening gulls in various seasons; the back matter includes additional facts, plus a round-up of other gulls and where they live. If the last line of the main text, ""It is fun to watch gulls exploring their world,"" sounds a little dull, it's only because readers of this book will be those who have already spent time watching gulls, and have turned to Gibbons's solid introduction for the facts.