When people think of reptiles in Southern Arizona they usually think of the big and impressive: rattle snakes, Gila Monsters and desert tortoises. If people think of frogs at all they think of monsoon season and the eruption of toads from the ground like giant green seedlings and the sounds of goats screaming which is what the Colorado River Toad mating 'song' sounds like.
But Southern Arizona has frogs too. Frogs differ from toads in several ways. Toads prefer a drier climate and can live dormant underground during the long months (or in some cases, years) of drouth that usually reflect their preferred habitat. Toads walk more than hop, and almost all contain a poison bearing gland behind the eyes.
Frogs are leaner, more streamlined, with damp bodies and an ability to leap. They prefer perennial water sources and a wetter habitat.
Unfortunately, in Southern Arizona the most likely frog species seen is the invasive bullfrog. This big green fellow was accidentally introduced and has spread to many perennial ponds in Southern Arizona. They are voracious predators and have played a large part in driving many Sonoran Desert frogs to the brink of extinction. Efforts are underway to reintroduce native frog species to perennial catchment ponds (called stock ponds) after exterminating resident bullfrog populations.
The Sky Island Alliance has been instrumental in bullfrog removal and reintroduction of the endangered native leopard frog to Southern Arizona. In addition to the leopard frog, Southern Arizona is home to 13 species of frogs.
Frogs, unlike toads, are not reliant on monsoon storms to become active. They tend to live near reliable water sources year-round, and so as long as the days are warm enough, frogs will be active. Many of the frogs encountered in the Sonoran Desert are tiny, so watch your step! They are often as small as your fingernail. They can also blend in well with their background, and since much of their habitat is rock and gravel, do not if they appear more toad-like than what people have come to see as frog like.
Frogs, like most reptiles can be difficult to identify. Fr identification purposes, take a snapshot of your find and then look for its picture on the internet. Frog colors can vary widely based of location and habitat.
Take this month to appreciate these little understood and rarely seen animals in their native landscape. Take a hike to a perennial water source and sit in the sun and if you're lucky you may see a tiny frog clinging almost invisibly to the granite by your feet.