California’s Mojave desert tortoises move toward extinction. Why saving them is so hard
For decades, the California desert tortoise has been the emblem of what ails the state. Their numbers are in a free-fall: in recent years, they’ve declined by at least 60 percent.
A few years ago, the desert tortoise population sat at about 90,000. Now, it’s down to about 10,000.
Last summer, state officials started working with a local non-profit organization to try to reverse the desert tortoise declines in California, which has been the subject of numerous studies.
But the organization, the California Desert tortoise Restoration Project, turned out to be less than savvy: The tortoises it selected for research were being released into areas where the species is already doing exceptionally well.
The state’s top wildlife official, David Wojick, quickly denounced the project, claiming that its focus on releasing healthy tortoises, rather than culling those found in distress, was the wrong approach.
It was the largest such conservation effort in the state’s modern history. And it was a spectacular failure.
But it was a spectacular failure, in part, because of a strange quirk of tortoise biology that makes them resistant to the kinds of efforts that can succeed in other species, like keeping forests healthy.
Here’s how it works: in the wild, desert tortoises are territorial. They defend a patch of ground with ferocious dedication and drive. And they’re very good at it. They can stand up to more than 600 sun and wind attacks a day.
In the wild, desert tortoises can travel long distances. When they lay their eggs, the females travel hundreds of miles to find the best nesting sites. And when they lay their eggs, the female tortoise actually sits on the eggs to give them the maximum amount of heat and moisture that is available. She even lets them incubate. It’s a process that takes about three weeks.
Desert tortoise eggs in the wild don’t hatch.
