A young artist observes a hummingbird named Little Green that flits from flower to flower outside the boy's window. Baker (Quack and Count, 1999, etc.) creates brilliantly-colored cut-paper collages to illustrate the simple storyline following Little Green's flights of fancy around the boy's yard, told in lighthearted rhyming couplets with just a few words in large type on each page. He shows Little Green's flight path with sketchy swirls of white paint swooping across vibrant turquoise-blue skies and lots of bright red and fuchsia-pink blossoms favored by hummingbirds. Baker's collages in this book are very similar in style to those of Eric Carle, and alert children will delight in searching for the tiny caterpillar camouflaged on every page or spread (perhaps a tip of the artist's beret to the master of collage picture-book illustration, from his heir apparent). Continuing glimpses of the boy with his sketch pad and paint brushes lead the reader to expect a hummingbird painting by the young artist on the last page, but the artistic punch line is the boy's multi-colored interpretation of the bird's zigzagging flight patterns. This simple, satisfying story will work well with two- and three-year-olds right up to first-graders, and the large full-page and full-spread illustrations and lively text make this a fine choice for story hours with bird or artist themes. (Picture book. 2-6)