Well lo and behold the stuff was growing. And not just a little bit. I kept removing the straw and found more and more green. The stuff took off over the entire area.
Here's a closer picture. I'm no expert at identifying plants. To me, it all looks like clover.
I'm going to wait until the stuff is really established and tall before taking down the netting. I can only imagine what those chickens would do to it at this point.