Although I had encountered Couch's spadefoots, Scaphiopus couchii, pretty much throughout their range in the United States, I had never happened across a breeding congress such as I was then listening to in southern Sonora, Mexico.



Created by the seasonal rains (known as "monsoons"), a newly flooded playa stretched ahead of us in the darkness as far as the beams of our flashlights could penetrate. Spadefoots in the hundreds, probably actually in the low thousands, sat at the edges, floated in the shallows, and continued to access the still enlarging puddle from all sides.

Fortunately it was late and only an occasional vehicle traveled the busy road next to which we were parked. Most of the frogs and toads that attempted to cross made the trip safely.

The incessant bleats of the Couch's spadefoots dominated the chorus, but the quacks, trills, peeps, and burps of other anuran taxa were impossible to ignore.

Couch's spadefoots are little (two to two and a half inch) yellowish "toads" that often have overtones of army green or brown. Like other spadefoots, they have a single heel spade. But in the case of the Couch's spadefoot, the spade tends to be elongated and sickle-shaped rather the the "teardrop" shape of other species.

Unlike the true toads, all spadefoots have vertically elliptical pupils, a definite giveaway.