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Earth Notes: Summer Spadefoots


The sound of monsoon rains beating the ground is irresistible to one animal in particular. A toad-like amphibian called a spadefoot responds instantly to rain, emerging from an underground burrow where it stays dormant most of the year.

Spadefoots, or spadefoot toads as they’re often called, aren’t in fact true toads. Their eyes are a distinguishing feature, with vertical, catlike pupils. Spadefoots are generally about two inches long, ranging in color from green to gray to brown, with relatively smooth skin. There are several different species known in Arizona and on the Colorado Plateau.

One feature they all share is a sharp, bony “spade” on each hind foot. It helps them dig away loose dirt and gravel as they back into the ground. Spadefoots spend dry times – maybe nine or ten months a year – in burrows of their own making, or by taking over existing homes of gophers and squirrels.

Their favorite habitats are lower-elevation playas and alluvial fans, washes, stream edges, and temporary ponds and pools. Some also range into sagebrush, pinyon-juniper and pine zones.

With the arrival of heavy summer downpours, spadefoots come out mostly at night in big congregations. Their bleating, trilling or snoring sounds can be heard a long distance. This is their breeding season, and these small amphibians must live fast to take advantage of the brief monsoon rains. Females can lay many eggs, and tadpoles hatch within days, metamorphosing into adults in a matter of weeks.

Like so many creatures in hot, dry landscapes, spadefoots survive by their keen relationship with rain.