Some species of frog native to Michigan struggling in River Rouge watershed, new survey finds
WARNER, NH - APRIL 15: One of the species of frogs that lays eggs in vernal pools is the spring peeper, a tiny frog that is easily missed. (Photo by Mark Wilson/The Boston Globe via Getty Images)
(FOX 2) - Frog and toad species who emerge early in the year in Southeast Michigan did so in fewer numbers in 2023, a survey of their populations found.
Volunteer efforts to track numbers of different amphibians that live in the Rouge River Watershed put on by the Friends of the Rouge organization revealed numbers of wood frog, chorus frog, and spring peeper species are down.
Meanwhile, amphibians that emerged later in the year did better. Lauren Eaton, who manages the survey, said warmer winters and chaotic weather in the spring may be behind the lower frog and toad numbers.
"Early callers are having a harder time adapting to changes," she said. "If you're a tiny being in a wetland, and it's warm and sunny for two weeks, then cold and frozen, I would imagine that's difficult to adapt to those shorter-term fluctuations to temperature."
All three early caller species have struggled over the past few years. Surveys of wood frog, spring peeper, and Midland chorus frog populations show their numbers appearing below average for at least three years.
Eaton said wood and chorus frog species act a little like canaries in a coal mine. They are some of the first to react to shifts in weather patterns and populations of insects they like to eat. A late frost in the spring can create havoc for those species, which are already challenged by habitat loss and pollution.
It's a different story for bullfrogs and American toads, amphibians that show up later in the spring. Their numbers are up.
The survey takes place over the entire year. Volunteers spend part of the night within a pre-selected block along the Rouge Watershed and record the sounds of frogs and toads that can be heard. The blocks are a quarter-square-mile big. Data from 149 blocks were submitted.
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The survey is among a number of volunteer-led efforts to better understand and restore the Rouge River and its surrounding habitats following decades of legacy pollution and development.
Before going out, volunteers use an app called Froggyvoice for training. It includes the calls that each native frog and toad species uses.
Wood frog, Hylarana daemeli, at night, Jourama Falls, Paluma Range National Park, Queensland, Australia. (Photo by: Auscape/Universal Images Group via Getty Images)
Beyond assessing the water and air quality, noting the populations of vegetation and wildlife that live in the region serve as good indicators for the health of the entire system. The watershed has come a long way since community efforts to clean up the environment began.
"The Rouge has certainly improved over years. It's not on fire anymore," said Eaton, adding that development continues to pressure key habitats used by the wildlife in the area.
"It's removing quality wetland habitat and degrading the quality of stream habitats. That is an extreme worry for us and something we think about a lot."
Anyone interested in participating in the Friends of the Rouge Frog & Toad survey can sign up here.