Only a heart of ice can be indifferent to zoo babies, and there are several show stealers here, among them a duckling captured in mid-sprawl and a dignified zebra colt. Nevertheless, you've seen better animal portraits (if you still have Ylla's Animal Babies, take another look). As for the concept, big and little as a comparative "relationship," the idea isn't developed; it's simply reiterated through bear and cub, sheep and lamb, camel and baby camel, etc. On the scale of Tana Hoban's previous work, rate this little. . . though its diminutive appeal can't be entirely dismissed.