The Spadefoot Toad Waits Under the Desert
A toad needs water to lay its eggs, but a spadefoot toad lives in dry country where rain may not come for months. How does it manage? It waits underground.
The spadefoot has a hard, sharp edge on each back foot, shaped a little like a garden spade, and it uses these feet to dig backward into loose soil, wiggling down until it is completely buried. Down there the soil is cooler and more damp than the ground above, so the toad stays motionless without eating, and it may spend most of the year in this condition.
Then a heavy rain falls. Somehow the toad senses the change and digs its way up to the surface. Soon the toads gather around the new puddles and pools. The males call loudly to attract mates, and the females lay eggs in the water.
The pools will not last long, because the sun will dry them out within a few weeks. For that reason, spadefoot eggs hatch quickly and the tadpoles grow rapidly, since they must turn into small toads before their pool disappears.
The young toads and the adults then eat as much as they can to build up their strength. When the ground dries again, they dig down to wait for the next rain.
The spadefoot has learned to live by a different clock, one that is set by the weather.