His bird companions are Snowbirds, Horned Larks, Crossbills, and Pine Grosbeaks; and he trembles lest the Great Gray Owl shall find his nestlings.
"But much as he loves cool weather for nest-building, he tires of it when the first frost touches the valleys, and snow caps the tops of his favorite mountains; for then his insect food grows scarce.

So he changes his summer habits; leaving the guild of Ground Gleaners, and becoming a Seed Sower, he follows the sun toward the tropics, where, likely enough, he tells the alligators long tales of northern lands and assures the water-moccasin that, big snake as he is, the mountain rattlesnake is quicker at biting.
"This Olive-backed Thrush you may _hear_ more often than see--he is a will-o'-the-wisp for shyness, whether on his journeys or about home.

But remember three things about him: his back is evenly olive (if you do not know what this dark-greenish color is, look at the olives you have on the table, or that stand in the tall glass jars in the grocer's window, for if you wish to study birds you must learn to distinguish this color from brown or the bright green); he has a cream-yellow ring round his eye; and lastly, his black-speckled throat and breast are dull yellowish." "Won't you let us go up to the wonder room now and see all these Thrush cousins in a row ?" asked Nat, when the Doctor had finished describing them.
"We will go up to the house and you may take a look at them, but I want you to be also able to name them from what I tell you; for when you see a bird out of doors you will seldom be able to have a stuffed one with which to compare it.
"Now we will make a procession of these cousins," said the Doctor, as they reached his study.

He then opened a glass case, took out six birds, and stood them on the window-sill.

"See, this is the way they go arm in arm when they walk in the great procession of Bird families: "The Bluebird and the Robin; "The Wood Thrush and the Veery; "The Hermit and the Olive-back.
"Rap, my boy, look at each one and see if you can remember some of the differences between them.