Some multi-coloured warblers live here

We have about 25 species of warblers here in Northwestern Ontario. While many of these little birds are mainly yellow or green, we do have some which, to say the least, are coloured differently.
Here are two.
•Black-throated Blue (Dendroica caerulescens)
This one is anything but yellow or green. As its name says, its throat, face, and sides below its wings are all really black. Wings, tail, and top of its head are dark grey-blue.
It has a bit of white on the edge of its tail.
The female is altogether different. Top parts are olive green, with a white slash through the eye. Underparts are pale yellow.
No other warbler is even remotely coloured like this male bird. He is indeed unique.
Breeding range is from the Ontario/Manitoba border to Nova Scotia, and down into the eastern States. This fellow builds a nest a few feet from the ground in open woodlands. It seems to prefer those areas which were once logged over.
•Black-throated Green (Dendroica virens)
Again, as indicated by its name, its throat and breast are dark black. Top of the head and down the back are olive-green but the sides of its head, and its neck, are bright yellow.
The belly and underside of the tail are white. This one is quite a dandy, too.
The female is, as always, duller than the male although the pattern is similar. She has the yellow cheeks and olive back but instead of the black throat, she has some blotchy feathers which tend to run to vague stripes on her sides.
This one is found from Alberta east to the Labrador, and down into the States, largely in the Appalachians. Its nests are in evergreens, at various heights. This is another one which is quite fond of cut-over areas, especially where there are some mid-sized evergreens.
Take note that there also is a Black-throated Grey Warbler but he makes his home in British Columbia.
These are a couple of the warblers which are very fond of the spruce budworm. At times, the numbers of these little birds rise and fall according to the budworm population. With heavy infestations, they may raise two or even three broods a year.
Take note that the wonderful colours I have noted are those of the male birds in the spring, mainly. This is the breeding plumage. They moult most of their fine feathers in the fall, when they almost all do turn dull olive green or yellowish.
So look for them in the spring, and early summer, when they are decked out in their best bib-and-tuckers.
In an area whose economy is largely driven by the forest industry, these little birds are our most faithful allies since they eat insects all the time.
Without these tiny protectors, the forest would simply disappear in a few short years.