Mourning The Desert’s Dying Icons

Dozens of pink ribbons tied on burro bushes and cholla cacti flutter in the wind that scours this square-mile plot of the eastern Mojave Desert. From a distance, they offer no hint of their bleak significance in the great, mysterious die-off.

Wildlife biologist Kristin Berry and I are making our way toward the single blue ribbon at the site, a few miles from the hamlet of Goffs. Tied to a cactus, it marks where field researchers Tim Shields and Kemp Anderson have found the day’s sole live desert tortoise, a youngster the size of a computer mouse, in a half-exposed burrow.

As we walk, a second, more sizable tortoise appears, as though conjured, in our path. I point at it in surprise, and say to Berry, “Look.”

Berry pulls up. “Tim!” she shouts. “Get over here, quick!”

Shields and Anderson hurry to join us.

This tortoise (having spotted it first, I think of it as my tortoise) is a glossy young adult female. She trundles over to us, noses Berry’s boots, then retreats to the miserly shade of a burro bush.

The researchers scarcely can conceal their excitement. “This is the first time we’ve seen two live tortoises on one day this year,” Shields says. “And I haven’t seen this, a tortoise just coursing around, doing its thing, all year.”

When researchers surveyed this site, about 20 miles west of Needles, in 1980, they counted 296 live tortoises, and in 1990, after several dry years, 220. In 1994, the last time they worked here, they noted 249. This year, halfway through their census, they’ve found 13.

Notches that researchers long ago filed into the skirt of its shell identify my tortoise as No. 386. Berry’s records show she was last encountered 15 years ago, an unusually long time for a tortoise at the much-studied Goffs research site.

Wearing latex gloves, Anderson picks the tortoise up and holds beneath its chin a small piece of paper with “386” written on it. Shields takes a mug shot of her face for Berry’s records.

Anderson measures and weighs the animal. Then he paints a tiny patch of whiteout on the back of her shell, writes her number on the patch, and covers it with a dab of clear epoxy to preserve it.

My tortoise measures 203 millimeters, a shade under eight inches, which indicates she’s in her early 20s. Since 1985, she has grown exactly 3.2 inches. Females take as long as 25 years to reach reproductive age. My tortoise likely just has entered that stage.

The slowness that characterizes everything the tortoises are and do is part of what makes them so beguiling; it looks like a kind of patience.

When young and small, the animals are ready prey for ravens, kit foxes, badgers and coyotes. They can only bide their time, wait out their liabilities, slowly grow and hope for good luck when they venture out of their burrows to forage.

The payoff comes when, at about 20 years of age, they reach a size at which only the most desperate and determined coyotes, the severest drought and, of course, the firearms and off-road vehicles of humans, can harm them. From then, it is thought, they can live another 100 to 125 years.

My tortoise shows, on her shell, signs of having been in the jaws of a predator, to no apparent ill effect. “When they’re this big,” Berry says, “they’re moving into the invulnerability state.”

Or, rather, they should be.

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THE UNDERLYING CAUSES OF THE COLLAPSE of California’s desert tortoise population, thought to have begun about two decades ago, still aren’t known. The state’s official reptile has been listed as threatened on state and federal wildlife lists since 1989.

At some of the 15 tortoise research sites in the state’s Mojave and Colorado deserts, upper respiratory tract disease has been the killer, but its source is undetermined. Berry has postulated that it was introduced by sick pet tortoises released in the wild by their owners.

At Goffs, the die-off has been caused by dyskeratosis, a shell disease that weakens the animals’ armor, opening the door to infection and predation.

Speculation about its cause ranges from airborne pollutants to emissions from automobiles on nearby roads to the tortoise’s feeding on non-indigenous plants that have taken hold in the desert. Necropsies have shown thyroid and liver abnormalities and elevated levels of lead, mercury and arsenic in tortoises from various study sites.

Perhaps, some have mused, the population crash is the downward arc of a long, slow natural cycle humans haven’t previously recorded. If so, it could take centuries for the population to recover, given the animals’ glacial reproductive capabilities. (They typically produce, on average, four eggs per clutch once a year, except in dry years, when they may not lay at all.)

Berry, 57, is more closely associated with the desert tortoise than any other scientist. A pale woman of serious mien and workaholic habits, she grew up in China Lake, a daughter of the desert.

Her population studies, done for the Bureau of Land Management beginning in the 1970s, first documented the die-off in California, the tortoises’ most important habitat. Her work led to the establishment of the survey sites, which she selected and where she runs monitoring programs. Berry, who now works for the U.S. Geological Survey, also helped found the Desert Tortoise Council, a preservation organization, and has published voluminously.

Hers has been a rigorously scientific campaign against, in a sense, all the pink ribbons at Goffs.

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THE PINK RIBBONS MARK WHERE SHIELDS and Anderson have found tortoise carcasses, often several within a few yards of one another, during the current survey.

We wish my tortoise good luck and leave her to her uncertain future. The lift of spirits she imparted quickly dissipates as we walk among the ribbons.

Beneath one, Anderson collects a scattering of tortoise shell sections, called “scutes.” From a nearby pile of dried coyote scat, he recovers a lower jaw, fragments of scute, leg bones and forelimb scales of an adult tortoise, No. 904, according to its shell notches, which should have been largely invulnerable to coyotes. Anderson puts the remains in a bag to be stored, as is every carcass, at Berry’s lab for further analysis.

Beneath another ribbon, Berry picks up the pale, empty shell of a 15-year-old female. “These are the heartbreakers,” she says. “This one was getting ready to be a breeder.” It died within the past year, she estimates. On its underside are the pale powder and lesions of dyskeratosis.

We examine the remains of another tortoise, and another, and another. Near a dry gully, we pause to consider an especially large and well-formed shell, now thin and sun-bleached.

It is No. 419, a tortoise that was first encountered in 1977, and had been sighted and measured alive a dozen times since. It was examined most recently in 1990, “probably by me,” says Shields, “because I was out here then.”

Shields, a field researcher for 22 years, consults the records. A specific memory of No. 419 clicks into place. “He was a beautiful animal, a gorgeous animal,” he recalls. The tortoise was large and quite old, judging from the incipient osteoporosis apparent on its shell. Still, it should have lived another two or three decades.

We look at half a dozen more carcasses, and I have seen enough. If the tortoise population at the Goffs site was healthy, this survey would turn up perhaps 40 carcasses. Shields and Anderson aren’t even finished with their work, and already they’ve found more than 300.

We return to the small camp where Shields and Anderson sleep beneath the stars during the two months they work the site.

For Berry and her field researchers, it has been especially painful to document what has happened at Goffs. The site is pristine and its once-flourishing tortoise population more thoroughly studied than any other.

Uniquely at Goffs, researchers had established a “baseline” of information that might have shed light on the causes of the current catastrophe, had scientists been able to monitor the population frequently over the last half-dozen years. But reliable federal funding dried up in 1995, and since then Berry has had to make do with one-time-only grants on a catch-as-catch-can basis in order to conduct surveys, which typically cost between $20,000 and $30,000 apiece.

In the six years since they last were at Goffs, the population has evaporated. The current count would turn up only 30 live tortoises by the time it was completed in early June of this year.

“If we had been here we’d have had a much better chance of finding out what happened,” Berry says. “It’s much more difficult with so few animals remaining.”

Shields says, “We blew it at Goffs. We all got complacent because they were doing so well. In a couple of years, you’ll never know the population was here. It’ll be just another hunk of desert with no tortoises in it.”

Before I leave, Shields has one more thing to show me. He rummages around the campsite and returns with an immense tortoise shell he found here a few weeks ago. It is so large he has to hold it in both hands.

It is Tortoise No. 70, who last weighed, alive, 14 1/2 pounds, “the biggest wild tortoise I ever saw,” he says. “You should have seen his face.”

Standing there in the wind, the four of us ponder the shell in silence, trying to imagine the face.

“I don’t want to be focused on losses,” Kristin Berry says finally. “I want to be focused on recovery.”

The day for that, unfortunately, has not yet come.

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James Ricci’s e-mail address is james.ricci@latimes.com