HATO COROZAL, COLOMBIA — They look like hamsters on growth hormones, bark like dogs and swim as fast as otters -- all reasons why chiguiros, the world's largest rodents, are an object of unending fascination for zoologists and wildlife enthusiasts.
But ranchers here in northeastern Colombia fail to see the attraction. They claim that the rodents, which stand knee-high to humans and weigh as much as 120 pounds, consume valuable pasture, foul drinking water and spook their horses and cows.
That antipathy, plus a booming market for chiguiro meat in neighboring Venezuela, has prompted open season on the rodents and landed them on Colombia's endangered species list.
Rancher Magali Delgado says chiguiros, which were visible recently from the veranda of her house in this isolated settlement in Casanare state, are a costly nuisance.
"They are like having a pack of rats in your home," said Delgado, who complained that she has to buy expensive antibiotics for her cows when they drink the spoiled water.
"I have to defend my cattle. They are what I live from," said Delgado, a mother of three whose husband was killed by paramilitary fighters several years ago. She says she doesn't kill the rodents herself but doesn't stand in the way of hunters who do.
Chiguiro meat is considered a delicacy in Venezuela. Demand is especially strong this time of year, when Roman Catholics eat it during lent and Holy Week as a church-sanctioned substitute for fish and red meat. Chiguiros have been wiped out in Venezuela, which prompted the sharp increase in poaching in Colombia.
Over the last two years, 28 tons of chiguiro meat has been confiscated in illegal shipments by truck or plane to Venezuela, said Maj. Maria Antonio Sanchez of the Colombian environmental police. That's more than double the 12 tons the police seized in the previous two-year period, 2005 and 2006.
Biologists are concerned that continued killing of the rodents, which are also known as capybaras, will not only lead to their extinction but do irreversible harm to the savanna ecosystem.
Chiguiros eat plant life that might otherwise overwhelm the savannas, which are flatlands that receive enormous amounts of rainfall, attracting hundreds of species of migratory birds as well as mammals and reptiles, said Olga Montenegro, a biologist at the National University of Colombia.
At the same time, scientists such as Montenegro and government officials say the chiguiros are a resource that can be managed -- they reproduce fast enough that their herds can be culled at a rate of 10% to 30% a year and still remain viable.
The trick is in how to manage such a culling.
"The laws surrounding controlled killing of chiguiros are very rigorous, so people avoid them," said Saulo Orduz of the government's Corporinoquia environmental management agency. "We're trying to come up with another model to facilitate people taking advantage of the animals while observing environmental needs."
Legal killing and dressing of chiguiros would require an investment of as much as $15,000 in a temporary slaughterhouse that would abide by existing sanitary rules, Delgado said, a cost that makes legal killing uneconomical. So freelance hunters kill the animals and ship them to Venezuela as contraband.
Biologists are dismayed by the threat to the chiguiros, which once ranged over much of South America's Amazon basin and surrounding plains.
"If the chiguiros are lost, it's part of our natural heritage gone forever," university professor Montenegro said.
"They have a right to exist. After all, they were there before the cattle."