Illegally traded endangered species that escape,forming secondary populations,
offer hope to their long-term survival,a study suggests.“This first came to my attention when I read a news story about the seizure of an illegal shipment of 23 yellow-crested cockatoos(小葵花凤头鹦鹉),” said Luke Gibson,a college teacher.He learned that the species was critically endangered,which surprised him.
This encouraged Dr.Gibson and his colleague to investigate(调查)how a critically endangered species had become self-sustaining outside of its natural range.They discovered 49 cases of a globally threatened species becoming established as a separate population,which they hadn’t thought of,including the yellow-crested cockatoo in their city.
“This is a species which is primarily threatened by wildlife trade,” he told BBC News.“Poachers go out into the forest in its native range in eastern Indonesia and capture the bird and then ship them off,usually up to our city where there is a strong demand for pet birds.This is what has fueled the decline of this species in its native range.But it’s really interesting because that same cause also had another effect: some of the people who were keeping this species here accidentally or intentionally released them.” As a result of enough of the birds being released,it allowed a new self-sustaining population to be established in this city.
The government in Dr.Gibson’s city has made it illegal to capture the species,even though it is a non-native species.Because the city is affluent and relatively well educated,the cases of people breaking the law are extremely rare,explained Dr.Gibson,unlike in its native range in Indonesia,where capturing birds forms a major source of income.
However,there can be downsides(缺点)to the newly established population of endangered species,such as a limited genetic pool,and suffering from novel diseases.It did also present a possible “very interesting” opportunity for conservationists,Dr.Gibson suggested.This would involve “harvesting” some of the newly established secondary population,which may provide a way to help slow global biodiversity loss.
1.What was beyond Gibson’s expectations according to the first paragraph?
A.The high rate of wildlife trade.
B.The preciousness of the birds.
C.The fact that the birds nearly disappear.
D.The news that the birds were poached.
2.What happened unexpectedly when the birds were shipped abroad?
A.They formed a separate population. B.They were kept as pet birds.
C.They were traded illegally. D.They were killed for research.
3.Which can replace the underlined word “affluent”?
A.Peace-loving. B.Rich. C.Free. D.Environment-friendly.
语篇解读:本文是一篇议论文。调查显示,逃脱非法交易的濒临灭绝的物种形成次生种群,为它们的长期生存提供了希望。
答案及剖析:
1.C 细节理解题。根据第一段中的He learned that the species was critically endangered,which surprised him.可知,让Gibson想不到的是,这些被非法盗猎的小葵花凤头鹦鹉是濒临灭绝的物种。
2.A 细节理解题。根据第二段中的They discovered 49 cases of a globally threatened species becoming established as a separate population,which they hadn’t thought of,including the yellow-crested cockatoo in their city.可知,出乎人们的预料,这些濒危物种在新的地方形成次生种群。故选A项。
3.B 猜测词义题。根据句中的unlike in its native range in Indonesia,where capturing birds forms a major source of income可知,这个城市的市民比较富有。故选B项。
