The illustrator of Eve Bunting's "Tweak Tweak" and "Have You Seen My New Blue Socks?" makes his Clarion debut as author/illustrator with a tender book about loneliness and friendship. Leo, a mailman, takes in a small bird, Cheep, who missed the autumn migration of his flock.When spring comes and Cheep moves on, Leo is sad to see him go, but he also has hope, and the letter he has been longing for