The Chatham Island robin is a small endangered bird found in scrub forests off the coast of New Zealand. The robin is preyed upo
n 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
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.