As a boy on his family's farm, Andrew Kelly used to revel in spotting koalas.
"It'd be quite a novelty to see one," he recalled. But his childhood delight has turned into an adult dilemma.
By the time Kelly was running the 4,500-acre sheep farm with his father in the 1980s, the koala population had swelled: It wasn't unusual to see three or four in a grove of squat manna gum trees. By the early 1990s "it got way out of hand," Kelly says. Sighting 60 or 70 on a walk became the rule.
The koala is now the subject of emotional discussion among Australians, and Kangaroo Island, where efforts are under way to control the population, is one of the focal points of the debate.
"The hard thing with the koala is we've got two situations," says Toni Berden, a ranger and a resident koala expert. "In northern Australia they're not doing too well. But in southern Australia they're doing very well. Too well."
Kangaroo Island, where Kelly's farm is located, lies just off the coast of South Australia. It is home not only to koalas, but also to large populations of kangaroos, wallabies, and sea lions.
Hunted for their fur until the 1920s and dislocated by sprawling cities through the rest of the 20th century, koalas are considered an endangered species in some parts of the country.
The population has flourished on Kangaroo Island, however, since being introduced there in the 1920s by well-meaning conservationists. Safe from natural predators and from chlamydia (a disease that has killed koalas on the mainland), the island population doubles every three years, Ms. Berden says, with the total now estimated at 10,000.
Kangaroo Island's koala woes are just one example of Australian good intentions gone wrong.
Across the tropical north, poisonous cane toads - introduced to eliminate beetles devouring sugar cane - are on the move and threatening the country's unique flora and fauna. Descendants of early house cats have gone feral in the outback, pushing some indigenous animal species to the brink of extinction.
Farmers like Kelly backed an initiative to reduce the Kangaroo Island koalas by shooting them, but that was rejected in favor of a sterilization and relocation program. So far, 3,400 animals have been either spayed or neutered and 1,100 of the newly sterilized animals moved off the island.
"We've probably slowed the growth rate. But we haven't stopped it," says Bob Inns, who supervises the program for South Australia's Department of Environment and Heritage.
The sterilizations, which Mr. Inns and Berden say are painless, have had at least a temporary effect at the Kelly farm. "The trees are recovering, but not enough to handle that sort of population again," Kelly says.
But the Kangaroo Island program has its critics in the Australian Koala Foundation.
The environmental group's executive director, Deborah Tabart, dismisses the effort as further meddling with nature. There hasn't been enough study of the koala social structure, she says, and removing some of the animals or, at the very least, their ability to mate, may be aggravating the situation.
"If you take the leaders out of a family, you just get juvenile delinquency among the young males," Ms. Tabart says. That, she adds, means pubescent koalas that might have once been kept outside the group by its dominant males instead can mate freely, causing a population explosion.
Tabart also questions the damage claims by farmers like Kelly. On an island where forests have been cleared by farmers, the biggest threat to the manna and blue gums isn't the koalas, she argues: "Humans are the ones who have made this mistake and it's humans who have got to fix it up."
(c) Copyright 2000. The Christian Science Publishing Society