<f spring abound in the Arboretum! While the chirps of songbirds are perhaps a more well-known indicator of the season’s arrival, Spring also marks the beginning of breeding season for another vocal group of animals. Male frogs and toads, which can be heard in the Arboretum (particularly in floodplain forests, Kettle Hole Marsh, and Lyman Lakes), croak to attract mates through calls.
Since it is still early on in the season, the frogs have just begun singing. However, in the Arboretum, the soothing sounds of wood frogs, boreal chorus frogs and leopard frogs can already be heard. The wood frog call sounds similar to a duck, while the call of the chorus frog is like the sound of running your finger across a comb. Meanwhile, leopard frogs have a lower and more guttural call, akin to a motor boat engine.
While these tiny animals are hard to spot, the Arboretum does keep track of frog and toad populations through calling surveys in the spring. Similarly, the Minnesota Department of Natural Resources (DNR) sponsors and compiles Frog & Toad Calling Surveys using data from all over the state. Both Carleton and the DNR conduct these surveys to assess how populations and distributions of frogs and toads change over time with the goal of understanding what factors affect populations’ diversity and frequency.
The Arboretum also conducts the count to know what species exist and to make informed management decisions about frog and toad habitats. In past years, the Arboretum has observed and heard eight different species, including bullfrogs, green frogs, Copes’ gray treefrogs, gray treefrogs and American toads.
We hope to see you on one of our toad and frog surveys this spring! Surveys occur during the evenings and are weather-dependent, so watch our Facebook page for an announcement of the date.