Enemies.—Lewis O. Shelley, who as a bird bander has handled many downy woodpeckers, says in his notes: “I find this species practically free from parasites, but I have found among the feathers the two bird flies, Ornithoica confluenta and Ornithomyia anchineuria.”
Alexander Wilson (1832) shows that the house wren, although not an open enemy of the downy, causes it a good deal of annoyance by stealing its nest sometimes. He says:
The house wren, who also builds in the hollow of a tree, but who is neither furnished with the necessary tools nor strength for excavating such an apartment for himself, allows the woodpeckers to go on, till he thinks it will answer his purpose, then attacks them with violence, and generally succeeds in driving them off. I saw some weeks ago a striking example of this, where the woodpeckers we are now describing, after commencing in a cherry-tree within a few yards of the house, and having made considerable progress, were turned out by the wren; the former began again on a pear-tree in the garden, fifteen or twenty yards off, whence, after digging out a most complete apartment, and one egg being laid, they were once more assaulted by the same impertinent intruder, and finally forced to abandon the place.
Maurice Thompson (1885) describes thus the bird’s defense against the attack of a goshawk:
I once saw a goshawk pursuing a downy woodpecker, when the latter darted through a tuft of foliage and flattened itself close upon the body of a thick oak bough, where it remained as motionless as the bark itself. The hawk alighted on the same bough within two feet of its intended victim, and remained sitting there for some minutes, evidently looking in vain for it, with nothing but thin air between monster and morsel. The woodpecker was stretched longitudinally on the bough, its tail and beak close to the bark, its black and white speckled feathers looking like a continuation of the wrinkles and lichen.
More commonly, when attacked by a hawk, the downy dodges behind a branch and, if the hawk catch sight of it again, either winds round the branch or dives behind another one. By this adroit defense the downy has a fair chance of eluding the hawk’s attack.
Fall and winter.—We see little change in the behavior of the downy woodpecker at the approach of autumn, at the time when many of the migratory birds are beginning to show a daily increasing restlessness, seeming on tiptoe to start on their long journey, moving about actively in their new feathers, and breaking out sometimes with a phrase of postnuptial song. In the role of permanent resident, the downy remains calm in the midst of the bustle of travel; it may join the hurrying groups for a time, or become surrounded by them, but it does not catch the contagion of departure, and soon drops behind to continue its local round.
The downy is not forced to seek the sun and warmth and the inexhaustible food of the Tropics, for the woodlands of New England and southeastern Canada are stored with food that, with a roosting hole, enables the bird to withstand the severest winter. But this food is limited; the insects that have been multiplying all summer, thus adding continually to the woodpeckers’ supply of food, stop multiplying when the frosts come, and will add no more until spring.
The downy is not a bird that ranges widely in search of food; moreover, for protection against the weather it is held to the vicinity of its roosting hole. Therefore each bird, in order to be sure of sufficient food for itself during the cold months, must maintain dominion over a territory large enough to support it through the winter.
Thus it comes about that in autumn the downy does perforce change its habits, or rather its attitude toward other birds of its species. The families disperse, and until the next breeding season each individual becomes a solitary bird, living in a restricted region, which it defends against trespass, resenting and repelling the approach of any other downy woodpecker.