Chapter 6

Question 1

What are the three traits of a rare species?

Answer 1

Restriction to rare habitats, restriction to a small geographic range, and low population density.

Question 2

Why are some species restricted to rare habitats?

Answer 2

1. Some species are adapted to the conditions only found in rare habits
2. Some species might be out-competed by superior competitive species in other areas

Question 3

Why are some species restricted to a small geographical region?

Answer 3

Some barriers isolate the species

Question 4

Why is low population density a trait of a rare species?

Answer 4

1. Body size plays a role as large. animals need more space, so there is a lower population density.
2. There are not enough resources to supply the population.

Question 5

An example of low population density

Answer 5

Maned wolf

Question 6

Example of small geographic range species

Answer 6

Sui quid fish

Question 7

Example of a rare habitat species

Answer 7

Blind salamander

Question 8

Why are some species more vulnerable to extinction?

Answer 8

1. Environmental change can push rare species over the brink.
2. Demographic problems: An unbalanced sex ratio means the lower reproductive rate
3. Rare species suffer from bottlenecks, drift, inbreeding

Question 9

Four factors for increased vulnerability to human activities

Answer 9

1. Habitat Overlap
2. Human Targeting
3. Large Home Ranges
4. Limited adaptability / resilience

Question 10

What factors drive small populations to extinction?

Answer 10

1. Demographic Stochasticity
2. Environmental Stochasticity
3. Catastrophes
4. Genetic Stochasticity

Question 11

Who was Alwyn Gentry

Answer 11

Botanist who worked at Centinela Ridge