On ‘Leap Day,’ zoo open frog exhibit

These frogs aren’t the common plump, bumpy type.

Less than an inch long, the young “poison frog” is a brightly colored creature that looks as if it were made of shiny enamel. They come in many colors, too: yellow with bright blue legs and markings; black and yellow striped, resembling a bumblebee; blue swirls, almost like a china pattern.

These unusual frogs, which are featured in an exhibit opening today at the Gladys Porter Zoo in Brownsville, are in danger of being wiped out by habitat loss and disease, according to experts. More than one-third of amphibian species could become extinct in the next decade, biologists say.

The zoo’s new exhibit is part of a worldwide initiative to increase interest in frogs and other amphibians, and also to call attention to their increasingly fragile state in the wild, said Brian Henley, supervisor for the zoo’s reptile and amphibian exhibits.

“We’re trying to educate people about the mass extinction of amphibians,” Henley said. “About 120 known species have gone extinct in the last (few decades) … and more are threatened with extinction.”

In response to amphibians’ rapid decline, the World Conservation Union and the Association of Zoos and Aquariums have declared this year the “Year of the Frog,” and are launching public-awareness and conservation campaigns to address the issue.

Conservation groups must act fast to slow down amphibians’ staggering extinction rate, said Shelly Grow, conservation biologist for the Association of Zoos and Aquariums.

About one-third of amphibian species worldwide are in danger of extinction within the next decade, Grow said.

“It is the largest extinction rate of any class of organisms, much faster than extinction rates for mammals or birds,” she said.

In addition to the “normal bad guys,” as Grow calls them - habitat loss and pollution - a lethal disease is spreading through the Americas and killing entire species, experts say.

Caused by a fungus, chytid attacks the frog’s skin tissue and affects the animal’s ability to absorb water and breathe. Researchers have found that once the chytid-causing fungus comes into an area, about 50 percent of amphibian species are extinct within six months.

Stream-dwelling species, and species that live in mountainous areas, seem to be most affected by the disease, according to experts.

According to the Texas Parks and Wildlife Department, Texas has not had dramatic declines in the amphibian population. But several amphibian species in the state are endangered or threatened.

In the Rio Grande Valley, threatened species include the black-spotted newt, the Mexican tree frog, the South Texas siren - a type of salamander - and the white-lipped frog. Habitat alteration, pesticide use and other factors have hurt some of these species, according to Texas Parks and Wildlife.

The fungus that causes chytid is widespread in the U.S., but first came here decades ago and had already contributed to the deaths of many species before researchers identified it, Grow said. In Central and South America, researchers are now following its path carefully.

Conservationists also are trying to stay one step ahead of the fungus’ march through South America, and have decided to bring some species into captivity to protect them.

“It’s a threat that can’t be addressed in the wild,” Grow said. “The only way to save them might be to bring them out of the wild for awhile.”

The World Conservation Union has asked zoos and aquariums to take in vulnerable species, with a goal of protecting 500 types of frogs and amphibians. About 200 zoos and aquariums in the U.S. might ultimately participate in the effort, Grow said.

As a first step, about 100 aquariums and zoos are opening frog exhibits or offering educational programs on Friday - or “Leap Day,” as organizers call it.

At Gladys Porter Zoo, eight frog species, including four types of poison frogs, will be on display.

Poison frogs, which are native to Central and South America, are indeed poisonous to the touch. The tiny, colorful frogs’ skin secretions are toxic to predators and even humans, Henley said.

Some indigenous South Americans use the poison on darts for hunting. That’s why these frogs are also known as “poison-dart frogs,” he said.

Also in the exhibit are African bullfrogs from the Kalahari Desert and marine toads, which are native to the Valley.

The frog exhibit will be in the zoo’s aquarium throughout March, and then will have a permanent home at the zoo.

Organizers hope the exhibit will spark interest in the world’s unusual frogs and a desire to help protect them.

“It’s something we can all work on,” Henley said. “Pollution and habitat loss are far more detrimental (to amphibians) than a fungus, or anything else.”

If You Go

What: Frog Exhibit

Where: Gladys Porter Zoo

When: Today

Zoo Admission: $9 adults, $6 children (ages 2-13)

Hours: Monday-Friday, 9 a.m. to 5 p.m.; Saturday-Sunday, 9 a.m. to 5:30 p.m.

Threatened Amphibians

Rio Grande Valley

— Black-spotted newt - small, spotted salamander-like animal; found in wet areas, such as arroyos, canals or ditches

—Mexican treefrog - green-and-brown spotted, large frog; found in subtropical areas; breeds May-October coinciding with rainfalls

— Sheep frog - small, brown or olive-green frog; found in moist sites with arid areas; southern Texas is its northernmost habitat.

— South Texas siren (large) - type of salamander; found in wet areas such as arroyos, canals, ditches; hides in ground during dry periods

— White-lipped frog - small, gray-brown frog; found in grasslands, roadside ditches, variety of other habitats; often hides under rocks or in burrows; hurt by habitat alteration and pesticide use

SOURCE: Texas Parks and Wildlife