I love it when the names of animals make sense. Case in point: chinstrap penguins.
Chinstrap penguins (Pygoscelis antarctica) live in northern Antarctica and on several surrounding islands. And, as I’m sure you’ve guessed by now, they are easily identifiable by their chinstraps – a thin band of black feathers running from the black cap on top of their head along their cheeks and under their chins. It really looks like they’re wearing little helmets!
Chinstrap penguins aren’t huge birds. They average 28 – 30 inches (71 – 76 centimeters) tall and weigh about 7 – 13 pounds (3 – 6 kilograms). But what they may lack in size, chinstrap penguins make up for with sheer numbers: the global population is estimated at nearly 8 million pairs of birds.
Stone breaker
Chinstrap penguins have another name: ‘stone cracker’ or ‘stone breaker.’ This nickname comes from their high-pitched call, screeching call.
And when you consider the size of their colonies, you’re in for a noisy time. After spending the winter north of the sea ice, chinstrap penguins will return in huge numbers to their breeding grounds on rocky island coasts. The largest colony is found on the South Sandwich Island of Zavodovski and has over 1.2 million breeding pairs!
All of these birds get especially noisy during the breeding season. During his mating ritual, a male chinstrap penguin will pump his chest several times before screeching into the air. He’s quickly joined by other penguins, and a mass trumpeting ensues. Mass calling like this probably helps synchronize the breeding season.
Life in the crèche
Chinstrap penguins build circular stone nests for their two eggs on the rocky slopes in the Antarctic region. The most popular nesting spots are those higher up, as they become ice-free sooner. Using their beak and claws, chinstrap penguins can climb even rugged slopes.
While most other penguins only take care of their strongest chick, chinstrap penguins can care for and nurture both of their hatchlings equally. Both parents take turns keeping the eggs warm until they hatch. Each parent will spend several days at the nest before switching with their partner to go feed; during this time, the parents can lose up to half their weight.
Eventually, when they are between 20 and 30 days old, the chicks leave the nest and join the colony’s crèche. Crèches are groups of young penguins huddling together for warmth and protection, just like a nursery. This is why synchronizing breeding is essential: to keep your chick safe, you want as many other chicks in a crèche as possible to distract predators. Chicks are cared for communally until they reach two months old, when they are old enough to swim and catch food for themselves.
Sleepy time
New research, fresh off the presses: chinstrap penguins take 10,000 naps daily!
They appear to be taking advantage of microsleeps – brief slips out of consciousness that last only four seconds. Taking 10,000 of these microsleeps a day adds up to over 11 hours of sleep! And unlike us, who tend to struggle when we don’t get continuous sleep, the chinstrap penguins seemed to have no issues surviving on microsleeps. Perhaps even more interesting is that only nesting chinstrap penguins and not foraging penguins displayed this sleep pattern.
Researchers have a few theories on why microsleeps might have evolved in chinstrap penguins. First, it could just be a byproduct of living in a noisy colony. Maybe nesting penguins literally can’t sleep for longer without getting woken up. In fact, the penguins on the edges of the colony tended to have longer periods of sleep than those in the very middle.
Another possibility is that microsleeps allow parents to stay vigilant for predators. Nests are vulnerable to predators like brown skua and southern giant petrels, but snatching only seconds of sleep at a time would let chinstrap penguins stay relatively alert to danger.
Whatever the cause of the microsleep-strategy, I’m personally glad I don’t have to do it myself. I much prefer a full nine hours of sleep each night over thousands of continuous second-long naps!
Resources
Leave a Reply