Weird bird thing in Greensboro

Since the weather has been warmer, I have found three birds on the sidewalk. I was walking on my lunch hour each time.

The first one was a perfectly intact, beautiful iridescent green and yellow hummingbird. It was lying on the pavement, completely still. I nudged it gently with my foot, because I thought it was fake, but it was real(and dead).

I found another one in a similar position on the sidewalk of Bellemeade Street, when I was walking on my lunch hour a week ago. It was alive and breathing, but very still. Its head would move just a tiny bit, but it didn't fly away when I approached it. I almost stepped on it before I saw it.

Just yesterday, I came across a little gray bird sitting on the sidewalk, in front of my building. The breeze was ruffling its feathers. It appeared to be alive, about to take flight, but as I approached, it didn't move. I could see it breathing. I moved my foot almost to the point of touching it, but it still didn't move.

Coincidence? Or is there an apocalyptic plague attacking birds in Greensboro? Maybe they are zombie-birds. Maybe they are robot-birds sent to monitor my every move.