A Parade of Penguins

Exploring the 5 Penguins of the Antarctic Continent

A Chinstrap Penguin on Antarctica Photo by Eamonn Maguire on Unsplash

Antarctica is the fifth-largest continent on Earth but one of the least populated, either by man or by beast. The air temperature over the plateaus of Antarctica regularly dips below -60 degrees Fahrenheit. Nothing much larger than a mite lives on these frozen wastelands. The coasts are slightly more temperate, but even here survival is no easy task. A few exceptionally hardy seagoing species have carved out a niche for themselves along the coastlines, including numerous seal species and several varieties of bird, including albatrosses, gulls, skuas, and penguins.  

Penguins are flightless seabirds with powerful flippers in the place of wings. Their movement through the water is more akin to flight than to swimming, especially when hunting. Each of the eighteen species of penguin has a large head, a fusiform body, and short legs.

All penguins have unique adaptations for surviving their environment. The dark backs and white bellies of these aquatic birds provide camouflage, confusing ocean-going predators, and their webbed feet and short, thick tails help them to better maneuver through the water. Most penguins, like many seabirds, have a gland above their eyes allowing them to draw salt out of their bloodstream. This counteracts the high salinity of their ocean diet. Of the eighteen known species of penguins, five of them—Adélie Penguins, Chinstrap Penguins, Gentoo Penguins, Macaroni Penguins, and Emperor Penguins—live and breed on the continent of Antarctica.

1. Adélie Penguins—Pygoscelis adeliae

Adélie penguins and chicks. Photo by Martin Wettstein on Unsplash

Adélie penguins weigh between nine to thirteen pounds and average around one and a half to two feet tall. They are also the most populous of the penguin species, with a world population of between five and eight million birds. Their heads and backs are solid black, save for a white ring around the eyes, and they are exceptionally curious birds.

These boisterous penguins gather in great flocks at the edge of the sea, jostling and jockeying for position. Leopard seals, their main predators, often lurk in areas where penguins enter or exit the water, waiting to ambush a fat, tasty seabird for supper. Nobody wants to be the first bird in the water, but everyone wants to swim. Eventually, all the pushing and shoving knocks a penguin or two into the ocean. The rest of the flock soon follows suit if they see that it’s safe, leaping into the sea with reckless abandon.

Records of fossil eggshells indicate that until around 200 years ago, this species of penguin dined mostly on fish. Although the modern Adélie penguin occasionally hunts small fish and squid, their diet now consists mainly of krill and other tiny crustaceans. They usually stick to short dives of 3 to 6 minutes in shallower waters when hunting, but they have been known to dive deeper than 500 feet in pursuit of a meal.

During the breeding season, usually starting in late October, Adélies gather in huge breeding colonies, some over half a million penguins strong. Leopard seals are the adult Adélie penguins’ most feared predator, but the chicks and eggs are more likely to be targeted by predatory birds such as the South polar skuas, giant petrels, and snowy sheathbills.

2. Chinstrap Penguins—Pygoscelis antarcticus

Chinstrap penguins standing on ice Photo by Torsten Dederichs on Unsplash

Chinstrap penguins tend to weigh less—seven to eleven pounds—than Adélie penguins, but they stand a bit taller than their cousins, approximately two to two-and-a-half feet tall. They are named for the distinctive patterning of the black feathers on their head and face. Rather than an all-black mask like the majority of penguin species, chinstrap penguins sport a smaller black cap of feathers with a white face. A line of black feathers resembling a chinstrap extends across the chin or the front of the throat so that they appear to be wearing hard hats or bicycle helmets with chinstraps.

This breed is known to be not only one of the most abundant of penguins species, with the worldwide population exceeding 15 million birds, but also one of the worst tempered. They stake their claim by squawking loudly and slapping eachother, although there’s a fair amount of lunging and biting as well. These exceptionally territorial birds will not only defend their space against other chinstraps but they are also known to attack much larger penguins, including emperor penguins, to protect their chosen territory.

Chinstraps spend March through October living on icebergs in warmer waters. They hunt and forage in the sea, returning to the breeding grounds in late October or early November by the droves. The males arrive first, selecting one of the dilapidated nests from the previous year and rebuilding it using stones. The females follow a little less than a week later, searching for their mate. At some point in early December female chinstraps each lay two eggs. Both mother and father attend to the eggs in turns, and two gray, fluffy chicks hatch from the eggs just a little over a month later.

Chinstrap chicks remain with their parents for around a month. In early February each year, the chicks in the breeding colony gather together in huge groups known as creches. This behavior allows the adult penguins, who frequently lose as much as half their body weight while caring for the egg and chick, to go back to hunting and foraging while the juveniles remain relatively safe and protected in the creche until they are old enough to fend for themselves. Adult chinstrap penguins are preyed on by leopard seals and their eggs and young chicks are hunted by predatory seabirds.

3. Gentoo Penguins—Pygoscelis papua

Gentoo penguins jumping Photo by Long Ma on Unsplash

Gentoo penguins are the third largest of the penguin species, weighing in at around ten to twenty pounds and reaching between two and a half to three feet tall. This species is easily identifiable by the white stripe that extends across the top of their head like a bonnet, their longer, fan-like tails, and their bright red-orange beaks. The global population of Gentoo penguins is relatively stable, although the population on the Antarctic peninsula seems to be increasing. These flightless birds communicate with one another through many sounds, but the most common is a loud, throaty trumpeting sound.

Breeding colonies are found on ice-free surfaces both on the Antarctic continent and the sub-Antarctic Islands. Some colonies are positioned along the shoreline while others are further inland. Gentoos are known to be rather romantic penguins, often pairing up with the same mate over many breeding seasons. Once paired, infidelity is dealt with harshly, often resulting in banishment from the colony.

Males entice prospective mates by trumpeting loudly and by bringing them special stones. When a female chooses her mate, the couple works together to create an intricate nest of stones. After the pair completes their nest, the female lays two eggs. Both parents alternate handling egg warming duties, sharing the task for approximately 35 days, until the eggs hatch. They then work together to care for the chicks in the nest for another month, until they are old enough to join a creche of juvenile penguins. Gentoo chicks are the only penguin chicks to fledge before becoming independent, usually at just over two months old.

Gentoo adults are preyed upon by Leopard seals, while the chicks and eggs are hunted by skuas and giant petrels. In some areas, nests with eggs and chicks are at risk of being crushed by Elephant seals wandering into breeding colonies, though this is more common on the subAntarctic islands than on Antarctica itself. Gentoos are carnivorous birds with a diverse diet. They eat varying amounts of crustaceans, squids, or small fish, depending on the season.

4. Macaroni Penguins— Eudyptes Chrysolophus

The Macaroni penguin is similar in weight to the Adélie penguin, around nine to fourteen pounds. They tend to be slightly taller, though, typically a little over two feet in height. The bright yellow or orange crest of feathers that stand out on the top of their fully black head distinguishes them as one of only six crested species of penguins, and the only one to live on the continent itself. Macaronis have large, bright orange bills with patches of bare skin from the base of the bill to the eye.

They spend most of their life at sea but come ashore for a few weeks each year, usually around October, to gather in huge, densely packed breeding colonies. Although most penguins get around by wandering here and there, Macaroni penguins prefer to hop. These penguins have established breeding colonies in Antarctica and the subAntarctic islands, and even the southern tip of Chile.

Though not strictly monogamous, Macaroni penguins often choose the same mate several seasons in a row. Once paired, the female lays two eggs but discards the first egg, which is frequently smaller than the second egg. Parents take turns caring for the eggs until they hatch, just a little over a month later. The male penguin typically guards the chick while the female takes to the ocean to gather food. When chicks reach around a month old, they gather in groups, called creches, providing both warmth and protection from predators.

This variety of penguin eats mostly krill, but may also eat squid and small fish. During the breeding season, several types of lanternfish become more important as prey animals. They are preyed upon by Leopard Seals, Antarctic Fur Seals, and Orcas when at sea. On land, the chicks and eggs are at risk from skuas, sheathbills, gulls, and giant petrels.

5. Emperor Penguins—Aptenodytes forsteri

The largest of all penguins is the Emperor Penguin. As adults, they can reach over three feet tall and typically weigh between 49 to 99 pounds. Found almost exclusively in Antarctica, they are better able to handle the cold winters than most penguin species due to a few small adaptions.

Their large size and extra stores of fat help them to survive without eating for extended periods, and their accomodating natures facilitate the giant huddles that allow them to survive a long winter season. Their flippers and beaks are also smaller than other species in proportion to their bodies to help prevent heat loss and they have feathers on their legs to keep their ankles warmer.

Emperor penguins breed on sea ice during the bitterly cold winter months starting in April. Teamwork is essential to their success as parents. The female Emperors lay only one egg each, and immediately after laying their single egg, pass off the next stage of parenting to their partner. Males carry the egg on their feet, keeping it warm with a layer of warmly feathered skin called a brood pouch. They wait on the sea ice, guarding thier egg for a little over two months, eating nothing during that time. To stay warm, male penguins huddle together in huge groups, each taking their turns in the middle of the huddle. The eggs hatch around 65 days after they are laid, often corresponding with the return of the females. By this time, males may have lost up to 45 pounds of fat.  

When the females return from feeding they bring with them food for their offspring. Male penguins can keep chicks fed for a few days with a special substance they secrete from the lining of their crop, known as crop milk. It’s the food stored in the stomach of the female, however, that provides chicks with the nourishment needed to thrive. The chick is passed from the father’s feet to the mother’s, sometimes with reluctance on the part of the male, and the male returns to the ocean to feed.

Emperor penguins are expert divers, equipped with solid bones to withstand oceanic pressure, and a reduced need for oxygen. This gives them the ability to dive deeper than 1500 feet and stay under water for twenty minutes or more. They feast on small fish and squid, especially the Antarctic silverfish, though they eat crustaceans too once in a while. Like other penguins, adults are preyed upon by leopard seals and orcas, while skuas and giant petrals frequently make meals of either eggs or chicks.

Although their breeding colonies may appear vast, these unique and vital populations of birds are at risk. Climate change is melting the sea ice and reducing the number of krill in the ocean. Penguins that adapt to changing circumstances by changing their diets are better able to weather problems related to climate change.

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