Page:Popular Science Monthly Volume 17.djvu/404

390 it was about three and a half inches across and slightly hollowed, perhaps three quarters of an inch. This nest contained six eggs, speckled with reddish-brown.

Around the hole on the outside of the stub a circle of fresh pitch had been smeared by the birds, perhaps for the purpose of keeping out the ants with which decaying stumps are apt to swarm. I have never before heard or read of this habit; none of our ornithologists, so far as I can learn, make any mention of the fact; but since the above instance came to my notice I have learned of another case of the kind, where the stub was a white birch, showing that my example was not altogether exceptional, and the fact that it is unnoticed by our ornithologists may be owing only to a scarcity of observers.

The geographical range of different species of birds is not so definitely marked as might be supposed, for, although there are certain well defined boundaries which separate the birds of different parts of the world, and of different parts of the same country, yet these limits are being constantly broken over by accidental visitors from other countries, by the birds increasing their range, or by stragglers from other ornithological districts of the same country. A South American hummingbird was obtained at Cambridge, Massachusetts, a few years ago. The Egyptian neophron has been shot in England, and the European corncrake is occasionally found on the Atlantic coast of the United States.

The cliff or eave-swallow, perhaps, furnishes the best example of increased range to be found among our birds. When first discovered it was apparently confined to limited areas in the west and Southwest, but at present it spreads over nearly the whole country and is yearly increasing its limits.

In order to be more fully understood in speaking of ornithological districts, it may be well to cite as examples the two regions of New England sometimes called the Alleghanian and Canadian. These districts are divided by a line drawn from the coast of Maine, near Mount Desert, and running southwesterly on the ridge of high land which extends across the southern portion of the State into the highland region of New Hampshire, thence running northwesterly across Vermont. This division is so marked that some birds that are common in the southern district are almost unknown in the northern, where they may occasionally appear, however, as stragglers. Much more striking examples are sometimes seen, as in the case of a cardinal grosbeak that was shot at Orrington, in Maine, a few years since—this bird's habitat being the southern portions of the United States.

I recently had the pleasure of following up and reporting a most interesting case of the finding of birds beyond their supposed limits. In this instance the bird was the loggerhead shrike (Colluris ludovicianus), which is a resident of the Southern States, and not supposed to breed in New England. As the case is one of considerable interest,