Question

The Chatham Island robin is a small endangered bird found in scrub forests off the coast of New Zealand. The robin is preyed upon by introduced species such as cats and rats. In 1980, the population decreased to only 5 individuals and every individual today is a descendant of a single female. Which of the following is best illustrated in the decline of the Chatham Island robins?
1. Carrying capacity
2. Population bottleneck
3, Population overshoot
4. Type I survivorship

Answer 1

Answer: 2. Population bottleneck

Explanation:

A Population bottleneck is a term used to refer to an event that causes the population of a species to reduce in very large numbers. Such an event can be environmental disasters like famine, the overhunting of a species or the destruction of its habitat.

In the case of the Cha-tham Island Robin, the bottleneck event must have been the introduction of cats and rats which then went on to hunt the birds to near extinction.