FEDS MOVE TO LIMIT RAVENS IN CALIFORNIA DESERTS AGENCY'S GOAL IS TO PROTECT AREA'S THREATENED TORTOISE.Byline: ANDREW SILVA
There's always the disturbing part in those nature documentaries -- when the adorable little ones young children.
See also: Little wind up as a meal for some other predator.
Mother Nature is a harsh mistress, but there's nothing natural about the way common ravens have decimated the struggling desert tortoise desert tortoise
see gopherus agassizii. .
A plan to control ravens will soon be implemented by the U.S. Fish and Wildlife Service, the agency charged with protecting endangered species endangered species, any plant or animal species whose ability to survive and reproduce has been jeopardized by human activities. In 1999 the U.S. government, in accordance with the U.S. .
"There are problems with ravens that attack and eat juvenile tortoises," said Carl Benz, assistant field supervisor in the agency's Ventura office. "If we can reduce predation predation
Form of food getting in which one animal, the predator, eats an animal of another species, the prey, immediately after killing it or, in some cases, while it is still alive. Most predators are generalists; they eat a variety of prey species. , it will be an important step in recovery" for the tortoise.
The threatened desert tortoise has seen its populations plummet as it faces a gantlet of threats: habitat loss, disease, vehicles, livestock, and ravens.
"Tortoises are threatened by the death of 1,000 cuts," said William Boarman, a tortoise researcher.
Ravens used to be rare in the desert, with limited food, water or nesting sites. In the 1940s, naturalists had a hard time even finding ravens in the Mojave Desert Mojave or Mohave Desert, c.15,000 sq mi (38,850 sq km), region of low, barren mountains and flat valleys, 2,000 to 5,000 ft (610–1,524 m) high, S Calif.; part of the Great Basin of the United States. .
But as humans spread across the desert, the crow-like black birds flocked behind, able to find food in landfills, trash cans, campgrounds and outside restaurants.
Power poles, billboards, buildings, and even abandoned cars provided a vast network of places to build their nests.
Raven populations exploded sevenfold sevenfold
1. having seven times as many or as much
2. composed of seven parts
by seven times as many or as much
Adj. 1. in the western Mojave, scientists estimate. The population in the Mojave and Colorado deserts of California is thought to range between 30,000 and 45,000 birds.
Juvenile tortoises provide a ready meal. The shells don't get hard enough to withstand a raven's beak raven's beak
the coracoid bone in the bird. until the slow-moving reptile is 4 years to 7 years old.
"As the shell develops, it gets stronger so it can stave off the pecks from a raven," Boarman said.
Given that tortoises don't reach reproductive age until they're 13 to 15, losing the younger generation makes it impossible for the population to remain stable, much less recover.
An adult, fertile female desert tortoise lays close to six eggs a year, but most of the hatchlings are lost to predation. Recovery plans for the threatened reptile likened the desert tortoise to the California condor condor, common name for certain American vultures, found in the high peaks of the Andes of South America and the Coast Range of S California. Condors are the largest of the living birds, nearly 50 in. , the black rhino and the blue whale blue whale, a baleen whale, Balaenoptera musculus. Also called the sulphur-bottom whale and Sibbald's rorqual, it is the largest animal that has ever lived. Blue whales have been known to reach a length of 100 ft (30. -- all of which are in danger of extinction.
It's much easier for other species, including ravens, which can reproduce at ages 2 or 3, to generate a lot of new members in a hurry.
It doesn't help that tortoises are most active in the spring, during the same time the ravens are raising their hatchlings and most need food, Boarman said.
The plan preferred by the Fish and Wildlife Service is to restrict the food and water sources available to ravens, and to remove or kill ravens that are clearly preying on tortoises.