BIRDS ARE FLYING

The latest of Kaufmann's several books on birds, this glides through an explanation of what keeps them aloft (light weight, thin and hollow bones, feathers and bones that bend, bone and muscle strength) and a sampling of differences in speed, style, and direction. Children one step up the reading ladder can learn substantially more from Freedman's How Birds Fly (1977); but except for a possibly misleading early statement which might seem to dismiss wings and feathers as important for flight (what Kaufmann really says is that they can't account for the ability), this is done with Kaufmann's characteristic clarity, simplicity, and good sense.