Winter World_ The Ingenuity of Animal Survival - Bernd Heinrich [26]
On this day, when I found and looked at the nest of the red-eyed vireo closely, I was surprised to discover pieces of gray paper from the nest of a white-faced hornet that had been incorporated into the outside nest wall, along with the always present birch bark and spiderwebs. The white-faced hornets’ communal nests, unlike birds’ nests, are added to and grow throughout the whole summer. By fall, however, when the worker wasps and drones die and the mated queens hibernate underground, the wasps’ nests are abandoned. Pieces of the nest can then be removed with impunity, but merely touching an occupied nest, as is well known and as I confirmed in experiments where I agitated these wasps, instantly results in an exit of hornet guards that attack all moving objects nearby and sting them mercilessly. I presumed therefore that the piece of hornet-nest paper that was incorporated in what seemed like an outside decoration must have originated from an old, abandoned hornet nest, since a hornet would not hesitate to attack and sting, and likely kill, a bird or other small animal that disturbed the communal nest.
I seldom find a hornet nest. The vireos must have traveled far to get their wasp-nest paper. Was this a typical red-eyed vireo nest? I remember the first red-eyed vireo nest I ever found. I was eleven years old, it was my first spring in Maine, and I had climbed the big sugar maple tree next to the road on the Adamses’ farm, where I spent an ecstatic summer. The tree was one that Floyd, the father of the family, had tapped in the spring for sugar sap. I do not, of course, recall if it had wasp-nest paper on the outside, but I wish I did. But being alerted by this nest, and the memory of it, I then made a special effort to examine all red-eyed vireo nests that I found in Vermont and Maine. All twelve that I found had at least some white-faced hornet paper on the outside. Since a vireo nest is globular and resembles a white-faced hornet nest in shape, it seems plausible that incorporating wasp-nest paper would enhance that effect and keep the premier woodland nest predators (squirrels, chipmunks, and blue jays) from coming close. Indeed, a slight jiggling of a branch with a wasp nest causes the inhabitants to attack en masse—a response no squirrel or jay would want to risk. Even if one of these common bird feeder chow-hogs is only slightly deterred by something as seemingly trivial as a nest decoration, that might still make a big difference in the long run. I estimate that chipmunks and red squirrels alone raid well over 60 percent of all songbird nests in my woods.
Redstart nest in young sugar maple at the edge of a swamp.
The linings of the vireo nests were all of thin, firm fibrous strands, but the kinds chosen differed among the many nests. Long reddish dead white pine needles were used in two nests. Hairy-cap moss fruiting stalks were employed in another. Other materials included very thin grass stems, the dried stems of sugar maple flowers, fine strips of ash bark, the rachis from decaying fern fronds, and sedgelike fibers that I was unable to identify.
Northern oriole nest in elm.
As I left the hardwoods where I found the red-eyed vireo nest, I descended onto a beaver bog where the frozen pond surface was bordered with already long-yellowed dry sedges.
Patches of light brown cattails were giving way to spiraea bushes, and arrowwood thickets that then graded into alders and young maples. Red-starts and least flycatchers at the latter site wedged their nests into the vertical forks of young trees.