Rabbit Woes: Easter Icons Face Survival Struggles
for National Geographic News
|April 17, 2003|
Chocolate bunnies may be abundant this Easter season, but some real-life rabbit species around the world are becoming increasingly rare.
"We have lots of endangered rabbits," said Andrew Smith, a biologist at Arizona State University in Tempe and chair of a World Conservation Union working group dedicated to management and conservation of rabbits, pikas, and haresa family also known as lagomorphs.
Spain: European Rabbit
In some parts of the world, declining rabbit populations have strained natural food chains. The European rabbit (Oryctolagus cuniculus), for example, is a staple in the Spanish lynx's diet. But a pox virus, myxomatosis, has raced through rabbit populations on the Iberian Peninsula, making them so rare that Spanish lynx (Lynx pardina) there are on the verge of extinction, scientists say.
United States: Pygmy Rabbit
Elsewhere, disappearing rabbits can signal declining health of grassland and sagebrush ecosystems. In the United States, a coalition of conservation groups is petitioning the U.S. government to list the palm-sized pygmy rabbit (Brachylagus idahoensis) as a threatened or endangered species throughout its range. The rabbit is already listed as endangered in the Columbia Basin of Washington state.
Conservation groups cite loss of sagebrush habitat to forage for cattle as the primary reason for the species' decline. They say the species depends on sagebrush for 99 percent of its winter diet. Sagebrush also provides the rabbits, which are among the smallest in the world, with cover from predators.
South Africa: Riverine Rabbits
Some rabbit species around the world are being squeezed out by known factors such as development and agricultural pressures. Others are so little known that their conservation status is uncertain.
Among them is the South African riverine rabbit (Bunolagus monitcularis) which lives in seasonal riverbeds. The species is distinguished by its long ears, a black-brown stripe on its lower jaw, and a dark fluffy tail. Unlike most rabbits, the riverine rabbit produces just one offspring per year and an estimated total of four offspring during its lifetime.
"There may be just a few hundred and none are in protected areas, all are on private land," said Smith. Conservationists are working with landowners to develop protection plans for the rabbit, which the conservationists say will also help protect South Africa's riverside ecosystems.
Japan: Amami Rabbit
In Japan, the Amami rabbit (Pentalagus furnessi) is known to live on two islands covered in old growth forests. It was overhunted in the 19th century for meat and medicinal purposes and by 1900 its numbers had been significantly reduced. Today, about 3,000 rabbits are believed to exist on the islands but they are increasingly threatened with extinction due to development pressure.
"Last I heard local conservation bodies were trying to stop the development of a large golf course on one of these small Amami Islands," said Bell. Such development fragments the landscape, making it difficult for the species to survive.
According to Smith, on word that conservation biologists were pushing protective action for the rabbit, local people took action to push the rabbits over the brink of extinction. "They put in mongoose to eat the rabbits, they don't want biologists to save the forests," he said.
Mexico: Volcano Rabbit
Another isolated rabbit facing development pressure is the volcano rabbit (Romerolagus diazi), which is restricted to a pine forest habitat marked by unique clumps of grass found on a mountaintop outside of Mexico City. The city is encroaching on this habitat, although conservations are working hard to preserve it and the species, according to scientists.
Then there are rabbits that may be endangered, but have no recognized protection. One of these is a cottontail rabbit (Sylvilagus robustus) that is found only in the Davis Mountains of Texas in the area between Guadalupe and Big Bend national parks. When Ruedas tried to get it listed as endangered in Texas, he was told listing would make the situation for the rabbit worse. "Folks would shoot it instead of letting other folks know it is on their property," Ruedas said the officials told him.
South America: Brazilian Rabbit
Situations such as this lead Ruedas to believe that many more species than officially recognized are endangered. He also believes that several species of rabbits wait to be discovered. As an example, he points to South America where most rabbits are classified as the species Sylvilagus brasiliensis.
"That cannot be, that is the bottom line," he said. "I've looked at [forms] of brasiliensis and they are so distinct, not even close."
To remedy the situation, Ruedas suggests that more attention needs to be paid to documenting the number of rabbit species in the world and performing long term studies on populations to determine whether or not certain rabbit populations are naturally low or truly in a decline.
"The words endangered and rabbit don't come easily together in people's minds because they have such a reputation as being pests in people's minds," said Bell. "In reality a number of rabbit species are endangered. It is important to recognize that."
Australia: European Pest
Meanwhile, Australians wrestle with an overabundance of rabbits. English landowners introduced the European rabbit to the continent in 1859, seeking game animals for sport hunting. With no natural predators in their new homeland, European rabbit populations soon spiraled out of control in Australia.
Introduced diseases and other measures have reduced the population by at least 50 percent from its historic highs. But the rabbits still cost the country millions of dollars in lost farmland revenues each year, according to Brian Cooke, who studied the Australian rabbit population for the Commonwealth Scientific and Industrial Research Organisation, Australia's federal science agency, and is now a researcher at the Charles Darwin Research Station in Ecuador's Galapagos Islands
"It is hard to imagine that a pest Australians have been trying to eliminate could ever be thought of as endangered," said Cooke.
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