The Warblers of Autumn
By Al Lowe
At this time of year, the mass movement of small birds of the north is already under way. Songbirds by the millions are already on the move, or are gathering in flocks in preparation for their fantastic journeys to warmer and more hospitable climates.
One of the greatest groups of these, in North America is the Warblers. Warblers are very small, smaller then the common sparrows, and most of them are coloured greenish or yellow as their main hue. They all have small pointy beaks, and they move quickly and erratically through the trees in their eternal quest for insects. They are one of our greatest assets in the forested area. The insects consumed by these little birds outweigh by thousands of times those controlled by spraying, or any other man-made means. Our forests could not exist without them.
Wood Warblers, family Parulidae, are native to the new world only. There are 57 different species in the family. Of these, about 40 can be found somewhere in Canada, and perhaps 25 or so in northern Ontario. Some of these little birds, in their spring or breeding plumage, are quite prominently marked. A number of black or blue markings with bright yellow patches. Some have black or purple hoods or cheek marks. A few are black and white, or black, blue and white. And one or two are really different, they are black and white and orange. In the spring, many warblers are quite easy to tell apart from each other.
In the fall, however, it is a different story. So many of these little birds look almost alike, with varying degrees of pale yellow, olive green and grey, that they are very difficult to tell apart, even for the most experienced birdwatcher. This is especially true of the young birds and the females, To make it even worse, they flock together with the Vireos and Kinglets which are also mainly small, grey, green and yellow. Unless you are especially keen on birds, you might as well not bother to try to identify these confusing fall migrants. Wait till they get back their finery in the spring.
Warblers, though very small, are long distance migrants. Most of them winter in Central or South America. They make most of their migration flights at night. On a still night in the fall, you can hear continuous little cheeping in the night air above you. These will be the sounds of the warblers moving past, usually in flocks of thousands, or even several hundred thousand. At times, clouds of migrating birds nearly block out the radar patterns at airports and other radio installations. There are times, too, when flocks of the little birds become confused by city lights. Every year several thousand of them are killed because they fly into buildings like the Toronto Dominion
At this time of year, many of these tiny green mites are preparing to leave us. They are usually gone well before the first major frost. When the bad weather destroys the insects, the warblers' food supply is gone. And they should be gone too.