The Chatham Islands Robin (Petroica traversi), also known as the black robin, once had a dangerously small population — in 1980, only five birds remained, including just one fertile female, named Old Blue. With careful conservation, the population has now increased, but all modern black robins are descended from that small founding group.
This is an example of a genetic bottleneck, where a population experiences a dramatic reduction in numbers, leading to a loss of genetic variation.
Your Challenge:
What do you think a genetic bottleneck is? How could such a severe loss in population size affect the gene pool of the Chatham Islands Robin — and why does this matter for its future survival?