31. It appears that cheetahs in Africa suffered a major die-off about 10,000 years ago that has increased their vulnerability to extinction today. Why?
a) Overkilling.
b) Overspecialization.
c) Localized distribution.
d) Habitat loss.
e) Reduced genetic variability
32. In 1905 the Dawson caribou, a large mammal confined to some small islands, became extinct. What is the most likely ultimate cause predisposing it to extinction?
a) Overkilling.
b) Overspecialization.
c) Localized distribution.
d) Habitat loss.
e) Reduced genetic variability
33. In Canada, mountain caribou exist as small bands roaming over wide areas of old growth forest. Logging of old growth forest has been correlated with declines in caribou numbers. What is the most likely ultimate cause predisposing these caribou bands to extinction?
a) Overkilling.
b) Overspecialization.
c) Localized distribution.
d) Habitat loss.
e) Reduced genetic variability
34. The Asian panda, which feeds on a single type of grass, bamboo, is at risk of extinction. What is the most likely ultimate cause predisposing it to extinction?
a) Overkilling.
b) Overspecialization.
c) Localized distribution.
d) Habitat loss.
e) Reduced genetic variability
35. World fish stocks have declined by some eighty percent in the past forty years. What is the most likely ultimate cause predisposing fish stocks to extinction?
a) Overkilling.
b) Overspecialization.
c) Localized distribution.
d) Habitat loss.
e) Reduced genetic variability
36. American songbirds are vulnerable to habitat fragmentation. What major risk is posed by this problem?
a) Predation.
b) Overspecialization.
c) Localized distribution.
d) Environmental contamination.
e) Reduced genetic variability
