Sunday, January 04, 2004
Copyright © Las Vegas Review-Journal

THREATENED SPECIES: Helping Mother Nature

Nonprofit group works to protect desert tortoises from too much -- and too little -- human interaction

Betty Burge of the Tortoise Group shows a freeze-dried teaching specimen because her backyard tortoises are in hibernation. Photo by Gary Thompson. A tortoise takes an amble at the Desert Tortoise Conservation Center outside Las Vegas. Photo by Clint Karlsen.

Betty Burge of Las Vegas can't think of an animal more endearing than the desert tortoise.

"There's hardly an animal that you can walk up to in the wild, that's this big that's nonthreatening. Even children like them," says Burge, 71, who has largely devoted the past 31 years to studying and protecting the gentle reptile.

Aside from inexorable loss of habitat as city replaces desert, the tortoise's placid approachability also places it at risk, notes Burge, who helped found the nonprofit Tortoise Group. Since 1982 it has been advising people on the proper care, feeding and habitat for pet tortoises.

The group can be reached by calling 739-8043 or by e-mail at tortoisegroup@

worldnet.att.net.

"If you can pick up this adorable little animal and take it home, people will do it," Burge says. But taking a tortoise from the desert is illegal, she swiftly adds. The animal is a threatened species protected by federal law.

" `Taking' is a legal word (that covers) everything from `touching' to `killing,' " she notes.

Lest people think that just touching a tortoise in the wild is innocent, Burge says even a single petting can cause harm. A tortoise in the wild, if surprised by a person who suddenly approaches from behind, may entirely void its bladder out of fright. That can be a severe shock to an animal who may need to rely on internally stored fluids for up to a year in times of low rainfall.

Burge became interested in the tortoise in the 1970s while working at the Youth Science Institute, a San Jose, Calif., organization for teaching children about nature and conservation.

Docile animals make good demonstration tools for young audiences, and the desert tortoise was a natural, Burge recalls. The local species' natural range is the Mojave Desert in Nevada and California, stretching slightly into southern Utah and northern Arizona.

She moved to Las Vegas in 1972 to pursue a master's degree in biology at the University of Nevada, Las Vegas, with a special interest in the tortoise.

Scientists had not studied the animal much, Burge was surprised to learn. One 1948 study, she recalls, was the "first word, and pretty much the last word" on the subject at the time.

"Even in the little work I did as a master's student, I presented some new material," she recalls. Today, however, a scientific organization, the Desert Tortoise Council, also exists to formally study the critter.

Burge avidly measured such factors as the animal's usual range -- an adult male can make use of up to 100 acres -- and the temperature in a burrow -- at 20 inches below the surface, a burrow's end point stays between 35 to 50 degrees in winter.

The animal can move about 0.2 mph, comparable to a moderate baby crawl. To protect itself from summer heat, a large male tortoise will use as many as 24 burrows it has built or inherited on the acres it roams.

After receiving her master's degree in 1977, Burge worked as a biologist for several decades, doing government contract work, mainly for the Bureau of Land Management in California.

Today she is less active because of retirement and arthritis, but as passionate as ever about the tortoise.

Although desert takings of tortoises are against the law, Burge notes two osther ways that Southern Nevadans can legally acquire tortoises: if the animals are born in captivity or adopted from the Desert Tortoise Conservation Center outside of Las Vegas.

Burge's Tortoise Group screens adoption applicants for the center. The center is a holding and transfer facility for tortoises that are either removed from desert land that undergoes development, found wandering in urbanized Southern Nevada or turned in by pet owners.

"People have died and left their tortoises behind. They may have 60 in a yard," is how Burge recalls one memorable incident.

The center belongs to the federal Bureau of Land Management but is operated by a private contractor that is supervised by Clark County.

The center's living conditions are less than utopian for displaced tortoises. "They just can't handle a lot of crowding. They get diseased," Burge says. To keep its numbers down, the center relocates most incoming tortoises to undisturbed desert remote from roads and human dwellings.

Tortoise Group members spend unlimited time with adoption applicants. They visit back yards to check if burrows are properly designed and located. "Tortoises spend over 98 percent of their life in a burrow," Burge notes, factoring in winter hibernation and the need in summer to stay out of full sun.

Members also offer suggestions on what tortoise-tasty plants to include in the landscaping.

And they offer tips on barriers to foil flight by tortoises, who are innate escape artists. "They really move," Burge says. "It's part of their nature to distribute that way," spreading out rather than congregating.

At heart, the Tortoise Group is eager for as many people as possible to enjoy the tortoise's charms.

But Burge has little tolerance for individuals who casually or impulsively get into tortoise ownership. She disparages owners with a clutch of hatchlings, who "take them into the office and give them away like cookies," without ensuring the proper habitat or diet will be available.

In her back yard, Burge keeps about 12 female tortoises, one gender only for foolproof birth control.

"Horrible Harriet, she picks on another one. I have to keep them apart," Burge notes. Tortoises will confront each other with a bobbing and weaving of heads. If one can "hook" the projecting point of its lower shell on the other's shell, it may cause the other to flip over.

She teaches all owners to periodically check their yards for flipped tortoises. If two or more live in a yard, the owner also needs to check that one isn't routinely intimidating the other. The weaker one will avoid confrontations, often ruining its own health by failing to come out for food and water.

Asked why she bothers to assist a species that may be nearing extinction, Burge has a two-pronged response.

"The big principle is, they're (already) here. They have a right to be here. Extinction happens anyways."

But that's only her philosophic preamble. Burge sees a practical reason, too, for prolonging the longevity of the desert tortoise: "They're part of the food chain."

As in, the coyote prefers to eat rabbits and rodents. But in tough, dry years when rabbits and rodents are less plentiful, the coyote also can eat the crunchy tortoise. But if tortoises die off because of loss of habitat, then coyotes in future droughts may die off, too. So when rainy times reassert themselves, the rodents will rapidly replenish, while it will take longer for the coyotes to re-establish. Which might create a rodent explosion.

"The coyote is very useful to us," Burge says, "because he helps control (rabbits and rodents). But if you take the tortoise out of the equation? Who knows what you're lousing up, when you take out a species?"