Some of them will nest as far north as stunted trees and shrubs occur in Alaska, northern Canada and Labrador. A few of certain kinds will nest here, but most of them are here today and gone tomorrow. Only a few close observers of bird life know them well.
Warblers are important in nature and to man.
For it is in May, when the flower buds and leaf buds are opening on our shrubs and trees, that myriads of insects are emerging to gorge themselves upon the tender juicy blossoms, twigs and leaflets. Some feed in the tops of the taller trees, where they flit about incessantly. The Black and White Warbler, one of the first to arrive, searches up and down the tree trunks and larger branches like a brown creeper or a nuthatch. Some kinds prefer vegetation near streams, ponds and marshes. A few species eat seeds and small berries, but insects in the egg, larva, pupa and adult stages make up most, if not all, a warbler's diet.