英语听力：自然百科 猴子大闹波多黎各

The Lajas Valley in southwestern Puerto Rico is one of the island's richest agricultural areas, but the population of non-indigenous monkeys is running wild in this region, destroying farmers' crops, eating baby birds out of their nests, and generally causing havoc with the eco-system.

This facility in the northern part of the island houses around 30 monkeys that have been captured. Officials say at least 1000 of them were on the island. The population is left over from a now defunct research lab on a nearby island.

Our organization is worried about the fact that the monkeys have become a plague for farmers in the Lajas Valley, and you know, we know for sure that the farmers have stopped planting melons and pumpkins and other fruits that have been attacked by monkeys.

Robert Carlo is a dairy farmer with 900 acres in the Lajas Valley. He used to grow fruit until a troop of monkeys destroyed his watermelon crop. Now he grows hay.

The real damage I think is from the lack of crops that we have been able to produce. That is a real damage, not what we lost.

In addition to crop losses, the monkeys are blamed for a dramatic drop in the valley's bird population. Many of the monkeys are also infected with herpes B and hepatitis, so they are a hazard to humans.

The Puerto Rican government has begun working to solve the problem, instituting a 1.8-million-dollar program to study the population and capture the animals. Natural Resources Secretary Javier Velez says he is worried that the problem will become much worse over time if nothing is done.

We also have the complaint from farmers, where they report, probably two million dollars a year losses in their operations. And at this point what we are doing basically is to use a strategy to remove as many monkeys as we can.

The study has to determine that erecting electric fences to contain the monkeys is not effective, and that establishing a season for hunters to kill the monkeys is unsafe in thedensely populated area. This month the government finally began putting the monkeys down.

The first group of 16 monkeys was held in a ten-foot-long steel cage baited with food and equipped with a trip lever. Two of the monkeys were released with radio collars for further tracking. The others were killed with a single shot from a 22-caliber rifle.

Velez who is a biologist believes officials determined that shooting the monkeys was morehumane than lethal injection. He says he regrets having to kill the animals, but had no choice after 92 different organizations rejected them.