The last week of April plus the first two weeks of May is Warbler, the shortest, most frenzied month. Every day is Christmas, and Christmas Eve! And like the NORAD Santa tracker, the Cornell Lab of Ornithology posts a Live Migration map:
You can watch the flow of birds, the northward surge, which trails the sweep of sunset each night, petering out at sunrise the next morning (click on the animation). The map covers only the continental US, but southern coastal BC is geographically a continuation of Puget Sound, so whenever the top left corner of the map is glowing, it's time to get up, grab your binos, and rush to the nearest woodlot.
Even before getting there the neighbourhood is alive with birds, the street trees filled with the "thwips" of Yellow-rumps, the" needleneedleneedle" of Wilson's warblers, and the "zzzuuUURrurrrurrrrr" of orange-crowns.
Both kinds of Yellow-rumped Warblers, the Audubon's (note yellow throat),
and the Myrtle (white throat) are here.
BTW, "Yellow-rumped Warbler" is a pain to type, especially into a phone. (Anything with a hyphen.) Let's just go with Myrtle. Okay? Good. (As long as "Myrtle" refers to a plant, not a person's name. I'm with those in favour of changing species names that are patronyms.)
For example, Wilson's Warbler. Change it to Other Yellow Warbler. (There's another one already called the Yellow Warbler.)
Orange-crowned Warbler is descriptive, but not adequately. It's basically just a green bird. Some may bear a smudge of Cheetos powder atop the head, but you rarely see that. You actually also rarely see the bird, mostly just hear it. Call it Greenish Warbler.
Townsend's Warbler, a joy to see among the Myrtles, Other Yellows, and Greenishes, should also be renamed. I don't encounter them often enough to supply a suitable habitat-related name and am fine with leaving its renaming it to someone who knows more about them. For me, they're always a pleasant surprise; I didn't see one until I moved to the west coast. West Coast Warbler? (Note, I could have inserted a hyphen, but refrained.)
But then it's mostly done. There are also Black-throated Gray Warblers (an okay descriptive name, but a pain to type (hyphen)). I only see a few each year. There are also McGillavry's Warblers, which are rare skulkers whose name should be changed not only because it's a patronym, but also because I'm not sure how to spell it.
Also note: The Pacific Northwest Coast has nowhere near enough warblers. We have about 5, well, 6, including Common Yellowthroat. Eastern North America has 87 (or so), including Ovenbird, 2 Waterthrushes, and other things not named warbler. Redstart! Oh to see a Redstart again.
Back here: Also among the warblers, habitat-wise and migration-wise, doing its own burbly, awkward, thrashing about thing, is the Warbling Vireo, which actually warbles. Most warblers do not, but resemble distantly-related European birds that perhaps do. The history of bird taxonomy is as fraught with cluelessness, politics, and cultural imperialism as anything else.
The song of the Warbling Vireo is the background to Warbler. It has stopped now. Warbler is over, the month is done.