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Scientists Work To Save Mississippi Gopher Frog

Posted on: Sunday, 12 October 2008, 09:35 CDT

The nation’s most endangered species, the Mississippi gopher frog, has faced challenges in producing offspring, but this year, nature gave them a break.

The frogs breed in shallow ponds that often dry up in the summer, stranding tadpoles.  Over the last 10 years, summers have been hot, and dry, leading to very little reproduction for the species.

In 1998, scientists studying Glen’s Pond in coastal Harrison County, Mississippi, saw 161 froglets hop out of the pond.  This year scientists saw 181 tadpoles survive a deadly parasite and head into the surrounding DeSoto National Forest.

Scientists saved seven generations of Mississippi gopher frogs by hatching eggs in a lab and putting tadpoles in screen-covered outdoor tanks.

According to researchers, fewer than 100 adults live in the wild, while another 75 live in zoos in New Orleans, Memphis, Detroit, Miami, and Omaha, Neb.

"Our efforts have managed to stave off likely extinction but there's a long way to go," said Joe Pechmann, of Western Carolina University. Pechmann has studied the frogs since 2002.

Researchers estimate the Mississippi gopher frog population each year by watching the breeding that occurs in Glen’s Pond. Counting the population is nearly impossible as the frog lives underground, in stump holes, and burrows dug by animals.

The frog, which is native to longleaf pine forests from western Alabama to southeast Louisiana, has a breeding call that sounds like snoring. They also feature bumps on their backs that secrete a bitter, milky substance used as a defense mechanism.

The species faces dangers like predators that eat their young, human destruction, and pollution in their habitat.  The forests making up the frog’s natural habitat has all but been destroyed by timbering in the region. 

According to researchers, an estimated 170 frog species have been lost in the last decade.  Another 1,900 are believed to be threatened.

Until 2004, Glen’s Pond was the only known breeding spot for the species.  A small colony has since been found in another location, while a third was created.

"People look at temporary ponds and they think there's something wrong with them," Pechmann said. "But the reality is, there's a lot of species such as gopher frogs that depend on temporary ponds; they can't live anywhere else."

The ponds are normally located in prime development areas. Researchers worry that they won’t be able to perform controlled burns that are needed for the forest and animals near Glen’s Pond because of a nearby housing development. A spokesman for Tradition Properties Inc., who owns the development, said they are making provisions to allow the burns to continue.

Tadpoles were not able to survive droughts in 1999, and 2000.  In 2001, researchers called on the National Guard to truck in water for the pond.

Pechmann set up tanks in 2002, and scientists have released 2,000 tank-raised froglets into Glen’s Pond.  Another 3,000 have been released at another colony being overseen by researchers.

At the Memphis zoo, researchers have been using in vitro fertilization to breed more frogs.  "We'll probably end up trying to breed them several more times this fall," said Andy Kouba, head of the Memphis zoo's research department.

Froglets get marked each year.  This year, 480 were marked in large enclosures to see whether the species could survive in a less than ideal habitat.

Successful breeding is still a few years away.  Males mature in less than a year, but females can take up to four years to sexually mature.

If wild froglets were to survive, it would triple their population.  That will not happen.

"Those little frogs are snack food or finger food for a lot of things in the woods," said biologist Mike Sisson. "The vast majority ... will not make it to adult frog. That's the nature of the business if you're an amphibian."

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On the Net:

• Western Carolina University
• ARTICLE: Memphis Zoo Fosters Endangered Frogs

Source: redOrbit Staff & Wire Reports

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