Ok, here's the scoop on the poop possibilities:
We have a dog. A greyhound, she has small poops that don't look like these.
We have a few neighborhood cats that don't usually come in the yard: see above mentioned greyhound.
We have bunnies. These aren't round bunny poops.
I'm sure we have toads.
I'm sure we have snakes.
We have loads of birds, but this doesn't look anything like my chicken poops, there are plenty of examples of those all over my yard.
Bobcats and coyotes have also been seen in my neighborhood, picking off those neighborhood cats that people leave out at night.
Our house backs up to a long, skinny piece of property that is undeveloped, they recently mowed for the first time this year. Before we put the garden fencing along the bottom of our barbed-wire along that property, we had possums and raccoons in our yard, but I haven't seen any in a long while. I googled what those poops look like and they more resemble a dog's poop than this.
My thought is some kind of reptile because there is that white stuff on the poop.