Q 01/05

Which rodents, the textbook ecosystem engineers, turn streams into ponds that other species use?

A) Beavers

B) Muskrats

C) Capybaras

D) Porcupines

Answer · why

A) Beavers

Beavers dam streams with trees they fell themselves, and the ponds and wetlands that form behind the dams trap sediment and pollutants that would othe...

Q 02/05

Which animals, freed for hunting in Australia in 1859, grew into a plague of hundreds of millions?

A) Foxes

B) Camels

C) Rabbits

D) Donkeys

Answer · why

C) Rabbits

Rabbits spread so fast that within ten years two million a year could be shot or trapped with no visible effect. A virus released in 1950 finally cut ...

Q 03/05

Gray wolves, moose and wild horses now roam the evacuated zone around which nuclear disaster site?

A) Fukushima

B) Chernobyl

C) Three Mile Island

D) Windscale

Answer · why

B) Chernobyl

Chernobyl was evacuated in 1986, and since then its wolves, wild boar, red deer and moose have multiplied so much that they have begun spreading beyon...

Q 04/05

Which giant snakes from Southeast Asia, once sold as pets, now hunt the mammals of the Everglades?

A) Boa constrictors

B) Green anacondas

C) King cobras

D) Burmese pythons

Answer · why

D) Burmese pythons

Burmese pythons were recognized as a breeding population in the Everglades in 2000, and road surveys since then suggest sightings of raccoons, opossum...

Q 05/05

Which bird, once the most abundant in North America at some three billion, was extinct by 1914?

A) Carolina parakeet

B) Passenger pigeon

C) Great auk

D) Heath hen

Answer · why

B) Passenger pigeon

Passenger pigeon flocks could take hours to pass overhead, but commercial hunting on a huge scale and the clearing of forests wiped them out. The last...