Only about an inch long, boreal chorus frogs
are a common inhabitant of central and
eastern Montana. Photo by Kristi DuBois.
All that water spread in sheets across central Montana now serves wildlife if not the farmer who wants to get into his field for spring planting.
Pick a road. Take a drive. Turn left 10 miles past nowhere and you will see water and lots of it. The melting snow from our long winter, now hopefully past, and recent rains have created shallow lakes that were just dry depressions not long ago.
Wildlife, in particular birds and amphibians, are taking advantage of those ephemeral ponds.
The sheets of water spread across a stubble field or emerging winter wheat are not good spots for waterfowl nesting, but the puddles do draw in waterfowl and shorebirds.
That’s because those wet spots offer food: insects now and amphibians later. It’s not unusual to see mallards, shorebirds, and Canada geese all swimming or walking around a shallow pool of water in a field. They are all there to eat.
Diving ducks, like canvasbacks or redheads, don’t frequent the shallow lakes. Those species are found more often where the water runs deep and they can, well, dive.
Puddle or dabbling ducks, such as mallards and northern shovelers, are the likely visitors because they tip up to feed.
Birds aren’t the only animals found in the temporary prairie waters. Amphibians, especially boreal chorus frogs, are there now and they are making quite a racket.
Boreal chorus frogs are the most common frog of central and eastern Montana, but are rarely seen due to their small size—adults are about an inch long—camouflage, and prairie life cycle.
However, they are easy to hear now as they breed and announce their presence, mostly at night but occasionally during the day.
Again, drive a deserted country road around sundown, stop the car near one of these short-lived prairie ponds, roll the windows down and turn off the engine. Chances are pretty good you’ll hear the chirping of dozens or even hundreds of these tiny creatures.
During their breeding cycle, April to June, chorus frogs lay eggs in clusters of five to 200, only about one inch across, attached to submerged grass stems or twigs.
The eggs hatch in about two weeks. Then the tadpoles take six to 10 weeks to metamorphose into frogs. That means the adult frog must produce eggs as soon as possible each spring, and the eggs—and later tadpoles—need a wet spot that doesn’t disappear too quickly. Sometimes they get lucky and the water lasts. Sometimes the water hole dries up and they don’t make it.
Even if the water remains, it attracts plenty of predators, like garter snakes and shorebirds. Tadpoles that survive and turn into frogs probably do not live much beyond three years.
After breeding the adult frogs move into adjacent uplands, sometimes as far as a half a mile away, spending their days underground or beneath vegetation, especially when the weather turns hot and dry.
Hot and dry summer days seem far in the future, but when they do arrive, we’ll probably miss this cool and wet season.