Chapter 3: Case Studies

Question 1

The Falkland Island wolf (Extinct)

Answer 1

The only native land mammal on the Falkland Islands. It lived in burrows and fed on ground-nesting birds.

It went extinct after settlers saw it as a threat to their sheep and killed it by shooting and poisoning. Because the wolves were tame and easy to find, they died out quickly.

After extinction, no major ecological changes occurred, except for an increase in prey numbers.s.

Question 2

The Iberian Lynx (Critically Endangered)

Answer 2

A predator that mainly hunts small animals, especially rabbits. Its specialized diet caused numbers to fall when rabbit populations declined. It also lives in isolated areas, making it vulnerable to habitat destruction and alteration.

Conservation efforts:
Hunting was banned in the 1970s, though some illegal hunting still occurs. The lynx is fully protected under national law in Spain and Portugal. Education programs, breeding and reintroduction centres, and national parks have been established to support population recovery.

Question 3

American bald eagle’s (Improved by intervention)

Answer 3

Native to North America and the national symbol of the USA. Lives near large bodies of water, nests in trees, and mainly eats fish, though it also hunts small animals like rabbits. Can live up to 40 years in the wild.

In the 1700s, there were 300,000–500,000 eagles, but by the 1960s, fewer than 500 pairs remained due to shooting, habitat loss, and DDT pesticide use, which caused thin eggshells.

Their population recovered after DDT was banned and laws were passed to protect them. By 2007, numbers rose to about 10,000 pairs, and they were removed from the endangered species list.

Question 4

Threats to the Great Barrier Reef

Answer 4

Great Barrier Reef (Australia)

One of the most biodiverse ecosystems on Earth.

Home to 1,500 fish species, hundreds of corals, turtles, marine mammals, and birds.

Main threats:

Tourism: Divers and anchors damage corals; some break coral for souvenirs.

Overfishing: Destroys sea floor, causes bycatch, removes key species.

Pollution: Fertilizers and sewage cause algal blooms.

Climate change: Warmer water = coral bleaching (about 60% affected).

Predators: Crown-of-thorns starfish population increased due to pollution and overfishing.

Storms and cyclones also damage corals.

Impact:

Leads to loss of biodiversity and irreversible damage to the reef.

Question 5

Danum Valley Conservation Area (DVCA, Borneo, Malaysia)

Answer 5

A protected rainforest area in Sabah, on the island of Borneo.

Example of how conservation and local economic growth can work together.

Was threatened by logging until the late 1980s, then given protected status.

Now home to 120 mammal species, including orangutans and Borneo elephants.

In the 1990s, a hotel was built nearby, boosting ecotourism — this supported the economy and raised conservation awareness.