The crested penguin has a strange behavior, he only wants to incubate one egg

This rare crested penguin (Eudyptes sclateri) from New Zealand is behaving strangely. Penguins in this rare category only want to incubate one egg and choose another egg to hatch.

The strange behavior of this vertical crested penguin is still not understood, why it only lays one egg and chooses another. When the first egg just lay in the nest.

In contrast, penguins that mate with monogamous partners require intense energy to lay eggs. Finally, researchers from the University of Otago in New Zealand have found the answer to this strange behavior of vertical-crested penguins.

After studying the reproductive biology of the upright crested penguin, known for its pointed crown of feathers, scientists learned that the mother penguin deliberately incubates one egg because she cannot feed two chicks at the same time.

Uniquely, this upright crested penguin only chooses one other egg to incubate (hatch) until it hatches. The crested penguin intentionally leaves the first egg and waits 5 days for the second egg.

“The second egg turned out to be much bigger than the first egg. In general, the second and subsequent eggs are usually smaller in different birds. In contrast to the crested penguin, the second egg was on average 85% larger than the first," said Professor Lloyd David of the Department of Communication Science at the University of Otago.

Size comparison of the first egg (left) and the second egg. crested penguin egg. Photo/Live Science

The results were published on October 12, 2022 in the journal PLOS One after researchers compared eggs from 158 penguin colonies. Researchers observed penguins and their eggs for 250 hours on the rocks of the Bounty Islands and Antipodes, landing in the South Pacific off the southeast coast of mainland New Zealand.

"We noticed that about 45% of penguins don't even bother to lay the first egg. They don't see it until after laying," says Davis. Unlike most penguin species, which build their nests out of rocks, sticks, and grass, up to 90% of vertical-crested penguins lay their eggs on not-so-large rocky surfaces. flat so that the eggs tend to rotate.

The only other species known to behave like the upright crested penguin is the Antarctic macaroon penguin, a close relative. "They are the forgotten penguins and little is known about them," Davis said.