Watch those warblers
One July day alongside the road at my family's cottage, I watched an unfamiliar, drab bird foraging through the brambles. She was small, the size of a warbler, but lacking the bright colours and markings of those species, except for an unusual, large white wing patch.
She turned out to be a female black-throated-blue warbler. This is the only eastern warbler species that exhibits strong dimorphism between sexes: the female looks much different from the male with his black face, white underparts, and vividly indigo-blue back. Perhaps the female's plain appearance serves as camouflage. This warbler is also unusual for nesting near the ground.
Doomed nest
In fact I found her nest that day a few years back. She vanished; I thought she had hopped away. So I approached the bramble patch only to startle her from a nest hidden among the raspberry canes. I was just as surprised.
And I was to be saddened the following day. That night one of the worst storms in memory struck cottage country. I awoke to a sky shimmering constantly. Lightning advanced like an army of fire across the still lake. Tornadoes ripped through Central Ontario, harming no one but doing immeasurable damage to property. The storm uprooted dozens of trees along our road to the nearest town, Dorset.
I went to investigate the warbler's nest the next afternoon. Rain had washed the whole bank of brambles down into the roadside. The nest hung useless. Several small eggs I had glimpsed the day before were gone.
These warblers usually nest successfully in our woods. But the eggs' demise symbolized a more widespread decline of the species.
Habitat loss
About 4,500 species of birds breed in the Americas. According to The Nature Conservancy, an estimated 1,000 of them are endangered or declining in numbers. Many of these species are among the colourful songbirds that spend their winters in the tropics, from Mexico to Cuba to Brazil, and migrate each spring to the temperate woodlands of North America.
Some, like the Kirtland warbler, are most severely threatened here on their breeding grounds. Since colonial times, Western civilization has wiped out vast tracts of forest, critical habitat for many species of warblers, vireos, thrushes and other songbirds.
But another threat is posed by the clearing of tropical rainforest. Ornithologists (bird scientists) have less information about these winter habitats. Some common songsters such as the scarlet tanager, hermit thrush and black-throated-blue warbler are in obvious decline. Part of the reason is thought to lie in tropical latitudes.
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