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Whatever the reason, the green frog was silent — at least until well after dusk had passed.
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Mary Strasser, left, and Diane Fernholz listen for frog calls in the marsh. The two volunteer for the Hixon Forest Nature Center. Erik Daily |
“If they’re calling, you’ll hear them,” said Diane Fernholz of Holmen, Wis., as she walked along the marsh trail.
“They are easy to distinguish from the birds,” added Mary Strasser of Onalaska, Wis.
The long-time friends have been attune to the sounds of native frogs and toads since they began volunteering with the Hixon Forest Nature Center’s Frog Call Survey five years ago.
They can quickly identify the bull frog’s “jug-a-rum,” as well as the loud, high-pitched peep of the northern spring peeper as they venture into the La Crosse River Marsh twice a month from April through August.
Some nights only a few frogs are heard, while others feature a full chorus in the marsh.
“We are just interested in nature,” Fernholz said. “We like to go hiking and observe wildlife.”
The La Crosse River Marsh Long Term Amphibian Monitoring Program was started five years ago by a Hixon Forest Nature Center volunteer working on his master’s degree at the University of Wisconsin-
La Crosse.
Joshua Kapfer found monitoring of the marsh had been intermittent, naturalist Stephanie Hanna said, and began organizing sessions for volunteers to listen and observe while gathering the information to track population trends.
Frog populations can give naturalists and experts an indication of what is happening in the environment, Hanna said. Their skin is permeable, absorbing what’s in the water, so they can be among the earliest indicators of any problems in their habitat.
To gather information, the volunteers head to six checkpoints along the marsh trail, where they record water and air temperature and listen for frogs.
The data eventually will be used to determine population trends.
Hanna offers training for all volunteers, and the nature center provides a monitoring kit.
“It is inexpensive to do, and volunteers help us,” Hanna said. “What more do you want?”
Autumn Grooms can be reached at (608) 791-8424 or agrooms@lacrossetribune.com.
