Depending on the pond location, the presence of birds seems to be a strong signal for how poorly the ponds are doing. Our ponds are next to the Trinity River, so they wouldn't be visited as the main source of water. However, the shrinking pools mean that fish are crowded together more closely and birds (for all their relatively small brain-to-body size) have figured out that hunting is easier in the dying ponds. We've seen a variety of herons, egrets, roseate spoonbills, and flocks of killdeer fishing along the pond margins. They're after the relatively smaller fish -- none of them are hunting the three foot long long-nosed gars. But as the pond degrades further and the tiny fish die or become hard to hunt, the scavengers show up -- crows and vultures -- as the big fish that were able to hide or were too big to eat start dying.
I walk the shores and count the sad tally of mortal remains -- 70 dead carp and catfish in one week on the dead pond next to Trinity River Audubon Center. On the margins of our ponds, I find the shells of mussels -- asian clams, sandshells, bluefers, giant floaters -- the large filter feeders that help keep the ponds healthy and clear.
The next step in the process is to start mapping where things were found -- where the mussel beds were and in which ponds, places where footprints are common (and which footprints), areas where grass or trees may not come back with the first rains. Although the rain will be welcome, a lot of water may cause unexpected problems.
We'll never know, though, if we don't document. And so I walk in the hundred degree weather and measure the ponds and scan the horizon and hope for rain.