Nothing to Sing About in This Hot Weather

A hermit thrush, a migrant in the Quinte area, but a breeding bird of slightly more northern regions, poured out his liquid flute-like notes two weeks ago from deep within the heavily forested area at Deroche Lake, east of Thomasburg. They have to be one of my favourites and it was a treat to renew my acquaintance with this woodland vocalist. A wood thrush also sang, and there was another, a veery, that called out its descending notes. Like a well-tuned orchestra of musical flutes, but each one delivered differently.  There was even a wood thrush last week in our backyard, an unlikely place to find one of these woodland songsters.

With the exception of these resident thrushes in Prince Edward County woodlands, we will stop hearing these songsters with the rich voices as we settle into mid-July. It will be too hot to sing for happy. As the days become progressively warmer, we will notice that bird song will suddenly fall silent. The wood thrush may continue sporadically but even he will draw his singing to a close if the heat persists. One exception is the red-eyed vireo whose monotonous notes of interrogation sift through the heavy summer foliage regardless of the temperature. It is one of few birds that can sing endlessly without taking a break, except to snatch an insect. One researcher, who obviously didn’t have a whole lot to do that day, decided to count the phrases that a single red-eyed vireo produced during the daylight hours, and tallied over 22,000 songs emitted during one entire day.

The plaintive call of the wood pewee is another you might hear, particularly if you walk any of the Quinte area woodland trails this summer. But other than that, and an occasional wood thrush or ovenbird still proclaiming their territory, there is not much to be heard. There is a reason for this and it goes beyond summer temperatures. Many birds will be molting soon and this can be a stressful time as birds lose their feathers, and grow new ones. It is a not a time when vulnerable birds wish to announce their presence by singing vigorously. It is best to remain quiet if you are to evade predators.

For most birds in the area, it has been a tough year on their feathers. These feathers took them here from their southern wintering grounds, enduring relentless, pounding rains in May and June. The males tirelessly flaunted their finery in hopes of impressing a female. Hours of foraging for food and repeated visits to nests with food also took their toll. To make the trip south this fall these feathers need to be replaced.

The change in plumage is gradual. It must be as birds would not be able to function. Some, like ducks, do become flightless for a period of time as new flight feathers grow in, some making feeble efforts to take flight, but in the end deciding on the shelter of some nearby cattails. Flightless ducks can still feed by dabbling or diving. For songbirds though that must retain the ability to fly in order to feed, the rebirth of flight feathers is a lengthy process. Wing and tail feathers, for example, are shed in coordinated pairs so the bird’s balance is not upset. Still, they feel weakened and somewhat vulnerable, keeping under cover and remaining quiet as they are still doing now.

One by one the feathers drop off. The loss is a set order in every species, old feathers falling out and new ones pushing in behind. Some have complex feather cycles. They may have partial or complete molts two or three times each year and therefore have both a spring and fall plumage. Other species require several years to reach adult plumage and change their appearance annually until they reach maturity. Eagles (five years) and gulls (three years) come to mind.

As for the warblers which Roger Tory Peterson has thoughtfully labelled in his guide as “confusing,” it becomes a whole new ball game. The dazzling yellow-rumped warbler, due to return from its northern nesting grounds early this fall, will leave puzzled new observers thinking that the County has been subjected to an invasion of strange looking sparrows with yellow rumps.

For now, just be content with listening to the rich notes of the thrushes and a few persistent ovenbirds and red-eyed vireos. The woods will become even more silent once autumn arrives and most species give up singing altogether, leaving us with only mysterious call notes as migrating birds communicate in another way.