VOA慢速英语--栖息地丧失导致猛禽数量下降（在线收听）

Birds of Prey in Decline with Loss of Habitat

Birds of prey, also known as raptors, are species of birds that feed almost entirely on meat that they hunt. A new report shows that these birds are dropping in number worldwide.

Researchers from the International Union for the Conservation of Nature and BirdLife International studied 557 raptor species. They found that 167 of the bird species are considered near threatened, vulnerable or endangered or critically endangered. Their study also reported that 18 species are critically endangered, including the Philippine eagle, the hooded vulture and the Annobon scops owl.

Gerardo Ceballos is a bird scientist at the National Autonomous University of Mexico. He was one of the writers of the study, which appeared earlier this month in the publication Proceedings of the National Academy of Sciences. He noted that other species are in danger of becoming locally extinct in some areas of the world. That means they may no longer play important parts as top hunters in those environments.

"The golden eagle is the national bird of Mexico, but we have very few golden eagles left in Mexico," he said. A 2016 study estimated only about 200 remain in the country.

Harpy eagles were once widespread throughout southern Mexico and Central and South America. But tree cutting and burning has greatly decreased their range.

The study found that 54 percent of threatened birds of prey that are active mostly during the day — including most hawks, eagles and vultures —were falling in population. The same was true for 47 percent of threatened raptors active mostly at night, such as owls.

Evan Buechley is a researcher at the Smithsonian Migratory Bird Center and a scientist at nonprofit HawkWatch International. He was not involved in the study. He said the biggest threats to birds of prey are habitat loss, climate change and poisonous substances.

The insect-killing substance DDT thinned eggshells and destroyed bald eagle populations in North America, leading to its ban in the U.S. in 1972. But Buechley said other threats remain, including rodent-killing substances and the lead in hunters' ammunition.

Many raptors feed on rodents and dead animals.

Widespread use of a drug used in farm animals led to the fast decline of vultures in South Asia. The birds died after eating animal remains, which decreased the population of some species by 95 percent in recent decades.

In East Asia, many raptor species reproduce in northern China, Mongolia or Russia. They then travel down the eastern coast of China to spend summers in Southeast Asia or India.

"Certain areas of the coast will see 30 to 40 species during peak migration," said Yang Liu. He is an ecologist at Sun Yat-Sen University in Guangzhou and was not involved in the study.

He said that areas with thousands of birds passing through them "are important to protect."

Stuart Butchart is chief scientist at BirdLife International in Britain. He said that most of the 4,200 areas identified by conservation groups as critical for raptor species worldwide "are unprotected or only partly covered by protected areas."

A 2018 study in the publication Biological Conservation found that 52 percent of all raptor species worldwide are decreasing in population.

Words in This Story

species – n. a group of animals or plants that are similar and can produce young animals or plants; a group of related animals or plants that is smaller than a genus

vulnerable – adj. open to attack, harm, or damage

endangered – adj. close to becoming extinct

extinct – adj. no longer existing

range – n. the region throughout which a kind of organism or ecological community naturally lives or occurs

habitat – n. the place or environment where a plant or animal naturally or normally lives and grows

rodent – n. a small animal such as a mouse, rat, squirrel, or beaver that has sharp front teeth

decline – n. to become lower in amount or less in number