We know little of the ways of the gaunt herons on their southward journey, but day after day, in the marshes and along the streams, we may see the great blues as they stop in their flight to rest for a time. The cold draws all the birds of a species together. Dark hordes of clacking grackles pass by, scores of red-winged blackbirds and cowbirds mingle amicably together, both of dark hue but of such unlike matrimonial habits. A single male red-wing, as we have seen, may assume the cares of a harem of three, four, or five females, each of which rears her brown-streaked offspring in her own particular nest, while the valiant guardian keeps faithful watch over his small colony among the reeds and cat-tails. But little thought or care does mother cowbird waste upon her offspring. No home life is hers--merely a stealthy approach to the nest of some unsuspecting yellow warbler, or other small bird, a hastily deposited egg, and the unnatural parent goes on her way, having shouldered all her household cares on another. Her young may be hatched and carefully reared by the patient little warbler mother, or the egg may spoil in the deserted nest, or be left in the cold beneath another nest bottom built over it; little cares the cowbird. The ospreys or fish hawks seem to circle southward in pairs or trios, but some clear, cold day the sky will be alive with hawks of other kinds. It is a strange fact that these birds which have the power to rise so high that they fairly disappear from our sight choose the trend of terrestrial valleys whenever possible, in directing their aerial routes. Even the series of New Jersey hills, flattered by the name of the Orange Mountains, seem to balk many hawks which elect to change their direction and fly to the right or left toward certain gaps or passes. Through these a raptorial stream pours in such numbers during the period of migration that a person with a foreknowledge of their path in former years may lie in wait and watch scores upon scores of these birds pass close overhead within a few hours, while a short distance to the right or left one may watch all day without seeing a single raptor. The whims of migrating birds are beyond our ken. Sometimes, out in the broad fields, one's eyes will be drawn accidentally upward, and a great flight of hawks will be seen--a compact flock of intercircling forms, perhaps two or three hundred in all, the whole number gradually passing from view in a southerly direction, now and then sending down a shrill cry. It is a beautiful sight, not very often to be seen near a city--unless watched for.