I haven't noticed any of the birds in my backyard mating twice in a year. I've got robins, blue jays, cardinals and sparrows. They're all fat right now because they feasted on the cicadas.
Besides the birds, I've got skunks, possums, deer, foxes, ground hogs, racoons, chipmunks and squirrels (black and gray) back there too. Lots of critters!!
The bluebirds will have two broods if the conditions are right. The first brood will help raise the 2nd. We've watched this at our home when we lived in GA. I've seen what look like tree swallow babies in our fields later in july after the first hatch. We have a mating pair of eastern (baltimore) orioles in our old cow path. Thats my favorite bird thing this year.
We have tons of critters too. This afternoon I saw a poecupine in our field. We have a herd of 9 deer as there's a new fawn jumping around out there. Groundhogs, red and gray squirrels, occasional moose, hawks ( I caught one with my bare hands in my chicken coop), vultures, least weasel (once),aprox. 100-150 chimney swifts in my chimneys, 3 bears a couple of years ago, turkeys, fischer cats!!! A whole flock of snow buntings spent about 3 weeks withus a few years ago( see second 2 pictures)The list goes on. No roo's though!