This could be just a wild statistical outlier but I thought I'd ask here since there are several bird lovers among the Yargbian contributors.
Over the past roughly 15 years I've noticed approximately 10 or fewer instances of birds crashing into windows on my house. It is an unusual event but I've learned the sound of it. It typically, if not almost exclusively, happens in the spring on very lovely days when I've recently cleaned the windows.
I have a picture window at the front and another at the rear that, during excellent weather conditions combined with clean windows (a rarity - I am not a compulsive window washer) produce the effect of being able to look in one side of the house and out the other as if it were a tunnel. All the bird strikes to date (well, prior to the past few days anyway) that I have been aware of are from birds attempting to navigate this "tunnel".
Over the course of the past weekend, however, no fewer than five birds have crashed into windows on my house and only two of those have been into the windows that create the "tunnel effect". The others have been into windows I have never before noticed birds crashing into. (I realize it may have happened hundreds of times that I am unaware of.) This means that roughly one third of the birds strikes of which I am aware have happened in the past 72 or so hours with the other two-thirds scattered over 15 or more years. This is not a case of being home for a larger number of hours or paying any greater than normal attention.
Lest the ladies and gents become overly concerned, these bird strikes almost never result in avian death. IIRC I've only had to bury one of the feathery critter crashers (from window strikes anyway - we won't talk about the one summer I tried to use netting to save my blueberries from the sharp-eyed, feather-wearing flocks). They normally fall to the ground and twitch about dazed and confused for a minute or two and then resume their flighty lives.
If anyone can offer a clue about this I'd be interested to hear it.