Archive: Detroit Zoo-Born Dusky Gopher Frogs Released Into the Wild for the First Time

Event caps a successful year for breeding and release of other critically endangered amphibians

October 25, 2018

ROYAL OAK, Mich., 

Twenty-five dusky gopher frogs bred at the Detroit Zoo’s National Amphibian Conservation Center were released in Mississippi’s Ward Bayou Wildlife Management Area this month as part of a cooperative program to restore a wild population of the critically endangered amphibian.

The event marks the first time Detroit Zoo-born dusky gopher frogs were released into their native habitat. Three other zoos – Omaha, Memphis and Dallas – also participated in the event, together releasing more than 300 frogs. The amphibians are tagged with identification to track their survival.

“It was gratifying to watch the frogs hopping off into the pond and peering at us on the shoreline – they looked completely at home, snapping at flies and acting like frogs,” said Dr. Ruth Marcec, director of the National Amphibian Conservation Center at the Detroit Zoo.

Once abundant throughout Louisiana, Mississippi and Alabama, dusky gopher frogs are nearly extinct. This species has an estimated population of less than 135 adults left in the wild, making it one of the top 100 most endangered species in the world, according to the International Union for the Conservation of Nature.

“With nearly half of the world’s known 7,878 amphibian species threatened with extinction due to habitat loss, climate change, pollution, infectious diseases and other factors, bolstering the population of these amphibians in their natural environment is critical to their survival,” Marcec said.

Dusky gopher frogs (Lithobates sevosus) – formerly known as Mississippi gopher frogs – are medium-sized frogs that are black, brown or gray with dark spots and ridges along their backs. Their skin is covered with bumpy glands that secrete a coating that protects their skin. When picked up, they cover their eyes with their forefeet, possibly to protect their faces until predators taste their bitter, milky skin secretions and drop them. They have loud, guttural calls that sound like snoring.

The release of the dusky gopher frogs caps a year of other successes for the Detroit Zoological Society’s (DZS’s) breeding programs for critically endangered amphibians. In June, 11,226 Puerto Rican crested toad tadpoles were released in the El Tallonal biological reserve, joining more than 52,000 Detroit Zoo-born tadpoles released in Puerto Rico over the past decade. In addition, 577 Wyoming toad tadpoles were sent to the Red Buttes Environmental Lab for release in a protected wetland in Wyoming’s Laramie Basin. Also, 61 juvenile striped newts were released in three wetlands in Florida’s Apalachicola National Forest near Tallahassee.

“It’s exciting to share our continued success with our amphibian breeding programs – we are committed to ensuring the survival of these species for many years to come,” Marcec said.

The dusky gopher frogs at the Detroit Zoo’s National Amphibian Conservation Center live in special bio-secure rooms behind the scenes and are not viewable to the public. The Zoo population serves as insurance against extinction until the species can be adequately protected in the wild and suitable locations are found for release.

When the National Amphibian Conservation Center opened at the Detroit Zoo in 2000, it was the first major facility dedicated entirely to conserving and exhibiting amphibians. The award-winning, state-of-the-art amphibian center is home to a spectacular diversity of frogs, toads, salamanders, newts and caecilians, many of which are the subjects of field research and part of cooperative management programs.