You will hear a lecture about the spirit bear and efforts to protect it.
First, you have some time to look at questions 31 to 40.
Now listen carefully and answer questions 31 to 40.
Today our ecology and conservation series turns to a highly endangered member of the black bear family.
Roughly one black bear in 10 is born with white fur because of an uncommon gene.
Local communities call it the spirit bear.
Their legends say its pale coat gives the animal unusual powers.
The bear is held in such respect that residents do not tell outsiders when they have seen one, thereby protecting it from strangers.
Its relationship with the old-growth rainforest is complex.
The bear depends on the forest's enormous ancient trees in several ways.
Their extensive roots prevent erosion along the banks of salmon streams.
Protecting those banks matters because salmon are the bear's main food.
The relationship also benefits the forest.
When bears eat salmon, they leave skin and bones on the forest floor, adding nutrients that support rich vegetation and many other forms of life.
Spirit bears now survive on only a few islands off the coast of British Columbia.
Fewer than 200 may remain.
Their survival therefore depends on preserving the fragile balance of the entire forest ecosystem.
Habitat loss poses the greatest danger.
Logging companies have removed large areas of forest and constructed roads that divide the bear's feeding grounds.
Numerous hibernation sites have disappeared as well.
Tree removal beside streams has harmed fishing areas, while the salmon supply is shrinking because fishing is currently unrestricted.
Together, these pressures undermine the bear's survival.
The danger is intensified by their consistently low rate of reproduction.
What can be done, community organizations, environmental groups, and the British Columbia government are cooperating.
The government now requires logging companies to improve their methods of logging.
That is encouraging, but it may not be enough to secure a healthy future population.
Further measures are necessary.
Maintaining the spirit bear's territory is vital, but its expansion must also receive greater attention.
A larger protected area would also provide space for other bears that are losing their homes.
That is the end of part four.
You now have one minute to check your answers to part four.