Question

Which one of the following makes a species most vulnerable to extinction?

• A. Low density throughout a large geographic range and in several habitat types
• B. Locally common in a restricted geographic range and in several habitat types
• C. Low density throughout a large geographic range and in a specific habitat type
• D. Locally common in a restricted geographic range and in a specific habitat type

Hint:

Species that are geographically restricted and dependent on specific habitats are at the highest risk of extinction, as they have fewer opportunities to adapt or relocate.

Answer 1

The Correct Option is D

We are given the options related to species vulnerability to extinction. The most important factors influencing extinction risk include geographic range, population density, and habitat specificity.

Step 1: Understanding the factors.
Species with a small geographic range and limited habitat types are more vulnerable to extinction because they are dependent on a specific environment, making them less adaptable to changes or disturbances.

Step 2: Analyzing the options.
- (A) Low density throughout a large geographic range and in several habitat types: While the species may have low density, the large range and multiple habitats give it more flexibility and resilience to threats. - (B) Locally common in a restricted geographic range and in several habitat types: The species is common in its region but still has a restricted geographic range, which can limit its survival chances. - (C) Low density throughout a large geographic range and in a specific habitat type: Even though the species is spread across a large area, its dependence on a specific habitat type increases its vulnerability. - (D) Locally common in a restricted geographic range and in a specific habitat type: This option presents the highest risk. A species that is locally common but limited to a small geographic area and specific habitat type has no room for expansion or adaptation in the face of changes.

Step 3: Conclusion.
The most vulnerable species would be one that is both locally common and restricted to a specific geographic and habitat type. Therefore, the correct answer is (D).

Final Answer: (D) Locally common in a restricted geographic range and in a specific habitat type