Not Bird Poop
Some insects and spiders mimic bird poop as a means of protecting themselves from predators.
I found this example on a leaf at Beaudry Provincial Park, Manitoba. If you look at it closely, you'll see what looks like the head of an insect towards the middle and the abdominal segments towards the top.
If you know what it is, please let me know.
Of course, I may be wrong. This may actually be bird poop, filled with undigested insect parts. I guess I should have collected it and dissected it to be sure.