GE B1 Unit 6 Reading Test A

Saving peregrine falcons: a success story

Stories about the environment are rarely good news these days: climate change, species in danger, and so on. (1)   One of these is the return of the peregrine falcon, a bird that almost died out completely.

The peregrine falcon is the fastest-moving animal on the planet. To catch another animal, a peregrine climbs high into the sky and dives down on the unfortunate animal it want to eat. (2)  

Numbers of peregrines fell greatly during the second half of the 20th century, so by the 1970s in the USA for example, only around ten percent remained. They were in real danger of disappearing completely and no one could work out why.

Then scientists discovered that a product called DDT, which was used by farmers to kill insects, was responsible. Small birds ate insects which were covered in DDT. Peregrines then caught and ate these smaller birds. (3)   The DDT caused the peregrines’ eggs to have very thin, weak shells so most of the eggs broke, killing the baby peregrine inside.

DDT was banned soon after this problem was discovered and slowly the numbers of peregrines started to grow. (4)   Peregrines usually build their homes (or nests) on high cliffs. The birds that peregrines eat fly much lower down, so a nest that’s high up allows peregrines to see their prey from above. (5)  

Some peregrines discovered that high-rise buildings in cities also gave them these benefits, so they made their homes there. There are now healthy populations of peregrines in cities such as New York, Paris and London as well as in their traditional homes in the countryside.