A walk in one of our extensive parks is nearly always rewarded by the sight of one or more of these interesting and attractive birds. They are usually so industriously engaged that they seem to give little attention to your presence, and hunt away, tapping the bole of the tree, until called elsewhere by some more promising field of operations. Before taking flight from one tree to another, they stop the insect search and gaze inquisitively toward their destination. If two of them meet, there is often a sudden stopping in the air, a twisting upward and downward, followed by a lively chase across the open to the top of a dead tree, and then a sly peeping round or over a limb, after the manner of all Woodpeckers. A rapid drumming with the bill on the tree, branch or trunk, it is said, serves for a love-song, and it has a screaming call note. THE WARBLING VIREO. The Vireos are a family of singers and are more often heard than seen, but the Warbler has a much more musical voice, and of greater compass than any other member of the family. The song ripples like a brook, floating down from the leafiest tree-tops. It is not much to look at, being quite plainly dressed in contrast with the red-eyed cousin, the largest of the Vireos. In nesting time it prefers seclusion, though in the spring and mid-summer, when the little ones have flown, and nesting cares have ceased, it frequents the garden, singing in the elms and birches, and other tall trees. It rambles as well through the foliage of trees in open woodland, in parks, and in those along the banks of streams, where it diligently searches the under side of leaves and branches for insect life, "in that near-sighted way peculiar to the tribe." It is a very stoic among birds, and seems never surprised at anything, "even at the loud report of a gun, with the shot rattling about it in the branches, and, if uninjured, it will stand for a moment unconcerned, or move along, peering on every side amongst the foliage, warbling its tender, liquid strains." The nest of this species is like that of the Red-eyed Vireo--a strong, durable, basket-like fabric, made of bark strips, lined with fine grasses. It is suspended by the brim in slender, horizontal forks of branches, at a great height from the ground.