The desert tortoise faces extinction unless there is a program to kill off at least some of the common ravens that are killing an increasing number of the reptiles, a detailed government study has concluded. Public responses to a proposed program to reduce raven populations are due by Feb. 13.
Experts from the U.S. Department of the Interior and the California Department of Fish and Game have collaborated in drawing up a detailed assessment of the situation and offering the options.
At the foundation of the problem are the intrusions of people that have so changed the environment that ravens, rare in the area only 40 years ago, are rapidly increasing. The birds now are a major cause of the dangerous decline in the tortoise. Both state and federal officials have proposed the tortoise for the endangered-species list.
"Over 80 individual desert tortoise shells have been found under single raven nests," the scientists report.
The only way to save the tortoises is to under-take a supervised program of poisoning and shooting ravens, with controls to minimize or eliminate the risk of affecting other wildlife in the areas of the Mojave Desert that are involved, according to the report.
Wildlife experts tell us that this is not the first time that a program has been proposed to kill one species to save another. Arctic foxes were killed with poison and gunfire to protect the Aleutian Canada goose, an Audubon Society official recalled. "You need to be darned careful, and it seldom works," he said, adding that "killing ravens is like bailing out the ocean."
But it seems to us that this plan is worth trying. The report reflects a painstaking effort to assess all the risks and alternatives. It will be important to remember, however, that ravens are not the only threat to the tortoise. Off-road vehicles used in uncontrolled fashion are another serious threat--a fresh argument to get on with proposals for expanded protection of the California desert.