What’s hopping in your yard?

A tree frog crouches in the sun.
A tree frog crouches in the sun.

“I am not a toad,” he thought as he crouched on a rock in the sun. Despite a cool wind, he could just barely feel the warmth of the sun’s rays spreading across his back. Somewhere in his peripheral vision a giant, clown-like face bobbed and babbled. The face leaned in closer, made an excited little chirp and then disappeared. Seconds later a smaller face loomed in view, made a similar, though higher-pitched sound, and then bounced away in dizzying circles. In the distance, the faces bobbed and babbled incessantly. Photos were taken, then quiet restored.

Minnesota is home to 14 species of frogs and toads. Their chorus rings out in the spring as males search for females to lay some eggs with, start a family. In late May, the voices you’re most likely to hear are American toads, as well as grey and Cope’s grey treefrogs.

There are many types of wetlands in Minnesota. Some, like this floodplain forest at William O'Brien State Park, are only wet during the spring and after heavy rains.
There are many types of wetlands in Minnesota. Some, like this floodplain forest at William O’Brien State Park, are only wet during the spring and after heavy rains.

Approximately half of all frogs and one-third of all salamander species in North America lay their eggs in ephemeral wetlands, also known as vernal or seasonal ponds, which form in low-lying areas on the landscape during the spring. Although most of these wetlands are only wet a few weeks every year, they provide important habitat for migratory birds, insects, and amphibians. Tree frogs and toads often show up in residential yards as well, especially near woods and forested areas. Tree frogs overwinter underneath rocks, logs and piles of fallen leaves, while toads burrow down into the ground below the frost line. If you find a greenish-brown, warty looking frog hopping clumsily in your yard, it’s most likely an American toad. In contrast, grey tree frogs and Cope’s grey tree frogs are greenish-grey, with smoother skin and are usually found clinging to windows on your house, or high up on leaves in the garden.

The leopard frog is one of the most common in Minnesota.
The leopard frog is one of the most common in Minnesota.

In addition to singing us gentle lullabies on spring and summer evenings, frogs and toads are also part of the web of life. In wetlands and along marshy lake edges, they are food for great blue herons, egrets and even mink. Tadpoles eat large amounts of algae and plankton, helping to keep the water clear, while frogs and toads eat a wide variety of creepy crawlies, including insects, slugs and snails. One toad can eat 10,000 bugs and slugs in a single summer.

Despite the abundance of species such as leopard frogs and American toads, other types of frogs are on the decline. The northern cricket frog, once found in southern Minnesota, has not been documented anywhere in the state for several years, and biologists suspect that a loss of forested wetlands is the reason spring peepers are disappearing from the Twin Cities metro area. Frogs are also quite vulnerable to pollution from fertilizers and pesticides because they have porous skin that can absorb chemicals in water. Chemical-laden runoff is especially deadly in the spring and early summer when frogs are laying eggs and tadpoles are hatching in wetlands and ponds.

Leave the land around lakes and wetlands unmowed to protect frogs and turtles and provide nesting habitat for birds.
Leave the land around lakes and wetlands unmowed to protect frogs and turtles and provide nesting habitat for birds. Photo from Blue Thumb – Planting for Clean Water. 

In your yard, you can create a healthy home for frogs and toads by leaving some of the grass unmowed near wetlands, lakes and woods; planting gardens with native plants; and using little or no chemicals on your lawn and gardens. Many gardeners will also build small frog ponds or toad houses to lure hoppers to their yards.  If you create a frog pond, be sure to include plenty of rocks to help the frogs get back out, as well as aquatic plants like water lilies, sedges and iris to provide cover for them to hide beneath. Don’t bother with aerators or waterfalls; the frogs actually like messy water better, and the leaves and bird droppings will attract and feed pond critters for the frogs to eat. Plant natives like swamp milkweed, joe-pye weed, cardinal flower, black-eyed susans, or ferns around the pond for additional habitat.

If you live on a lake or wetland, you’re probably already sharing your yard with frogs and toads. Leave an unmowed buffer along the water’s edge and around ephemeral wetlands to protect them from harm and contact the Washington Conservation District (651-330-8220) if you’re interested in doing more to improve your shoreline or wetland habitat.

Back in Stillwater, the bobbing heads returned two hours later to the sunny rock in the boulevard garden. Their grinning faces again loomed close and more photos were taken. The sun began to fade and from inside the house he could just hear a voice asking, “Isn’t that Hector, the toad you released last spring?” With a shrug, he tucked his little green body under a blue ceramic bird on the far edge of the rock. “I am not a toad,” he thought. “Can’t they tell I’m a frog?”