Summer World_ A Season of Bounty - Bernd Heinrich [23]
Already in the gathering dawn the phoebe is inspecting the two potential nest sites on the house: a one-inch shelf under the roof near the back door, and the bend of a drainpipe near an upstairs window. Now, as he inspected each of these sites, he was making soft churring calls and excitedly fluttering his wings.
On the next dawn he called continuously in the typical phoebe song—a short “fee-bee” alternating with “fee-bay,” at his typical tempo of about thirty phrases per minute, repeated with clocklike regularity. He called from the very top of a big maple tree, then flew over the forest in the direction of our neighbors’ house. I assumed this was a male recruiting a mate. Indeed, before the end of the day there were two birds around the house, and two days later they chased off a third. Both were then still inspecting the two potential nest sites.
Fig. 11. Phoebe at its nest on a board I put up inside our chicken shed. The speckled egg is one that a cowbird had dumped in.
By the third morning the pair were paying particular attention to just one nest site. They had chosen the thin shelf under the roof by our back door, which we use as our main entrance.
Further nesting progress was then suddenly interrupted. For a whole week there were dark skies and a drizzly rain that turned to snow. Both birds became silent, and then after a couple of days they became lethargic and fluffed themselves out. Soon their wings drooped rather than being folded tightly over the back as they had been before. There were no more flies to be had, at least not by the phoebe’s usual mode of hunting, which is to sally forth from a favorite perch to snag those buzzing by. There was no chance that any insect would fly by in a snowstorm. I wondered if the phoebes would survive. To my great surprise, one of the birds hopped like a sparrow onto the snow-free ground under my parked pickup, perhaps to try something different. It also hovered in front of the suet I had set out for woodpeckers, nuthatches, and chickadees, and eventually fed from it. How did it know this was food? There could be no genetic programming in phoebes to feed on suet. Maybe they had taken their cue from the other birds they saw feeding there—a possibility that could account for the behavior of many different kinds of birds with vastly different foraging techniques who all exploit the exotic food and feeders we provide for them.
When the weather improved, the phoebe pair again looked and sounded cheery. As before, they churred and at the same time fluttered their wings in apparent shivers of excitement when they perched at their chosen nest site. The phoebe’s song would from now on be repeated thousands of times like a mantra, and it brightens my day even before my morning coffee. I don’t know why a song that is as monotonous, unmusical, and undemonstrative as this one still has such a cheering effect on me. It can’t be the virtuosity of the performance. The phoebe is one of the passerines, or perching birds, the most successful (that is, the most diverse and numerous) on the planet. The passerines are divided into the songbirds—technically, oscines—and their less musical brethren, the sub-oscines, which include the phoebe. It’s a seemingly plain bird in all respects.
Although phoebes are not known as vocal virtuosos, they make many different sounds and gestures that are related to context and that evoke emotion. When “on territory” they begin calling vigorously before sunup, and they then become almost silent half an hour later. When mates find a nest site and show their enthusiasm with soft comfort calls, they come to a consensus or agreement with each other. When the adults start to build the nest, they also “chip” to each other, occasionally throwing in an excited “zeebit” or