My Spring Robin by Anne Rockwell, Harlow Rockwell (Illustrator)
Before finding the robin she is searching for, a child discovers other interesting fauna and flora in her backyard. Before she finds "my spring robin," she encounters a variety of signs of the new season in her backyard: a toad and an earthworm; crocus, forsythia, magnolia, violets, and daffodils blooming; and fiddlehead ferns emerging.
Last year's Spring post - http://teachingreaderstothink.blogspot.com/2011/03/for-first-day-of-spring-butterfly.htm
Here are some titles for you and your readers to enjoy . . .
http://delightfulchildrensbooks.com/2012/03/09/spring-2/