Earth Notes: Frogs on the Move
On the Colorado Plateau, life begins anew when the monsoon rains come — especially for native amphibians like the northern leopard frog. This beautiful, spotted, greenish-brown frog pays close attention to moisture, and starts to move on humid days and rainy nights.
Northern leopard frogs breed in early spring. Males attract females with a repertoire of snores, chuckles and grunts. Once bred, the female lays several thousand eggs in a mass in water. The tadpoles change into young frogs, timed perfectly with the rains of early July. That’s when both juvenile and adult frogs disperse to set up new territories and look for insects and other food.
On the plateau, northern leopard frogs historically lived at springs and in perennial wetlands and pools — some as high as 9,000 feet in elevation. But, these frogs have experienced dramatic declines in the West since the 1970s, as water sources have become scarce and nonnative predators like bullfrogs and crayfish have gone after them.
This summer, biologists with the Arizona Game and Fish Department and U.S. Fish and Wildlife Service are giving them a boost. From a few refuge sites on the Arizona Strip, they will translocate northern leopard frogs to new homes on the Kaibab National Forest. The hope is to rebuild the frog’s populations at safe, suitable locations.
They’ll also continue monitoring, restoring aquatic habitat and eliminating predators of this sensitive species, whose presence speaks of good, plentiful water.