Penguin Monogamy

Do penguins keep the same partner for life?

One of the best known facts about penguins is that they keep the same partner for life, but is this really true? At the recent International Penguin Congress, held in Cape Town in September, there were a couple of talks which addressed this.

The first was by Gisele Dantas, a researcher from Brazil who looked at Magellanic penguins. These penguins usually have two chicks and DNA studies were carried out on them to see whether the father was the same in all cases. She was surprised to find out that 31% of all chicks were not fathered by the male looking after them, and as many as 48% of nests had at least one “illegitimate” chick. What was even more surprising is that 6% of the chicks were not the offspring of either the mother or father, but she couldn’t explain this at the time. One interesting comment she made was that if the male had a worse body condition, then the mother was more likely to mate with other penguins while he was away feeding.

A couple of days later, Hannah Kriessel from Strasbourg University gave a talk on the mating behaviour of King Penguins on Possession island, a small dot halfway between South Africa and Antarctica. She was looking at the brightness of the colours in attracting mates and also the noise they make, as ways of being successful in finding a mate. As an aside to her studies, she found that up to 80% of the King Penguins swapped partners every year.

So, it looks like the nice image of faithful penguins has been well and truly debunked. In reality, at least these two species don’t stick to the stereotype.