Range. - North America from the Atlantic to eastern California, and from New Brunswick and Manitoba southward; winters from the southern half of the United States southward.
These uncivilized members of the bird world build no nests for themselves, but slyly deposit their egg in the nest of some other bird from the size of a Robin down, probably the greater number being in Warblers and Sparrows nests; the eggs are hatched and the young cared for by the unfortunate birds upon which they are thrust. The eggs are white, spotted and speckled all over, more or less strongly with brown and yellowish brown; size .85 x .64.
Range. - Southwestern United States and Mexico, wintering south of our borders.
This variety is like the last, but slightly smaller. The nesting habits of the two are identical and the eggs are indistinguishable, It is believed that Cowbirds do more damage to the smaller birds than all other dangers combined, as their young being larger and stronger either crowd or smother the other young or else starve them by getting most of the food brought to the nest.