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The banded penguins, such as the Humboldt and African penguins, have featherless patches on their faces and feet where they divert blood to cool when overheated.
Although feathers can be fluffed up or flattened down, penguins also use other methods to keep their temperatures at the right level. When cold, penguins rely on countercurrent exchange to warm up , a specific heat transferring mechanism that exchanges heat from warm blood traveling in vessels towards their legs and feet to colder blood leaving the area.
Penguins need to see clearly both on land and underwater. Terrestrial animals, including humans, rely on the cornea—the clear outer layer of the eye—to focus images using a property called refraction , a bending of light as it crosses through different materials.
As light travels through the air and enters the eye, it bends to the appropriate angle and creates a focused image on the retina. Penguins solve this problem with a flattened cornea and highly modified lens.
Their flattened corneas have less refractive power than those of terrestrial animals, enabling them to see clearly underwater. Their spherical lenses can compensate for the flatter cornea by also bending the light.
When fully constricted the pupil appears as a pin-sized square but in low light conditions it will expand an amazing fold—the greatest change in pupil size of any bird—to increase light reception. This is especially important when king penguins dive to their greatest depths, around feet meters. The contrast in light is equivalent to bright sunlight and starlight. By constricting the pupil to a pinhole in sunlight the retina is pre-exposed to the lower ambient light levels found at maximum dive depths where the pupil then fully expands.
Adapted to underwater conditions, penguins have shifted their visual light spectrum in favor of violet, blue, and green and to exclude red, a color that quickly disappears at depths greater than 10 feet 3 meters.
It is thought that penguins can even see ultraviolet light—emperor and king penguin beaks reflect ultraviolet rays, the only marine birds to do so. The display of ultraviolet could contribute to mate selection with both females and males preferring mates with stronger displays of ultraviolet reflectance. Like other birds, penguin ears lack external ear flaps. The ears reside on either side of the head as holes covered by feathers.
As any SCUBA diver knows, pressure changes from diving can damage the fragile structures within the ear. A study of the king penguin ear showed that their middle ear is protected from pressure changes during diving by a special organ made of cavernous tissue.
When ambient pressure increases the tissue expands into the middle ear to maintain a constant pressure. In the cacophony of hundreds of penguins on land a returning parent can pin point their chick from the rest of the colony based on its unique call.
One study of African penguins found their hearing range to be between and 15, Hz, but peak sensitivities were between and 4, Hz—in comparison, humans hear between 20 and 20, Hz. An acute sensitivity to sound may be a defense penguins employ in the face of predators like orcas and leopard seals.
One study showed even when asleep, king penguins could distinguish between predatory sounds and harmless sounds. In the presence of an orca call penguins flee upon awakening. Similar to migratory birds , penguins may rest only one half of their brain while the other stays vigilant, constantly monitoring the surroundings for possible threats.
Penguins have poor taste reception, similar to most birds. A recent study showed penguins lack the sweet, bitter and umami taste receptor genes, maintaining only salt and sour. Most birds only lack sweet. It is believed that the cold temperatures of Antarctica, where modern penguins evolved, contributed to the loss of these tastes as sweet, umami and bitter taste receptors function poorly in cold temperatures. Penguins also lack taste buds on their tongue, leading scientists to question whether penguins can taste at all.
The olfactory lobe in the brains of penguins is relatively large. Studies of African, Humboldt and chinstrap penguins indicate some penguins can detect prey using olfactory cues such as chemicals released by foraging krill. The Humboldt penguin uses smell to distinguish between related and unrelated individuals and to find mates. Penguins claim their own family, the Spheniscidae family, and are likely most closely related to other birds like the petrel and albatross.
There is still debate over the number of distinct species, but it is generally agreed that there are between 17 and 19 species see rockhopper and little penguin sections for more information. The species are divided among six genus divisions, or genera, commonly referred to as the crested, banded, brush-tailed, large, yellow-eyed, and little.
Macaroni Eudyptes chrysolophus - Macaroni penguins are the most abundant of all the penguins. The most southerly distributed crested penguin, they live along the coasts of sub-Antarctic islands and the Antarctic Peninsula. The lifespan of a Macaroni penguin spans from 8 to 15 years. Macaroni prefer krill but will also eat small fish and squid.
They are roughly Royal Eudyptes schlegeli - The royal penguin differs from other crested penguins in its orange plumage instead of yellow and white face. Some still argue that it is a white-faced variant of the Macaroni penguin due to genetic similarities but others point to distinct ecological differences and breeding isolation. Chicks take 35 days to hatch and become reproductively mature themselves after 5 to 6 years. Individuals can live between 15 and 20 years.
They mostly eat krill but supplement their diet with small fish. Royal penguins stand at 28 inches 70 cm and 8. Fiordland Eudyptes pachyrhynchus — Fiordland penguins have the characteristic yellow tufts of feathers like other crested penguins and live along the temperate rainforests of South Island and Stewart Island of New Zealand.
Unlike many penguin species, they prefer to nest isolated from other mating couples. The birds nest under forest canopy, in caves, under boulders and shrubbery, and in nests made of brush and grass. They eat fish larvae, crustaceans and squid. Breeding season begins mid-winter in July and egg incubation ranges between 4 and 6 weeks.
Adults stand 22 inches 55 cm at between 5. Rockhopper Eudyptes chrysocome - The rockhopper penguin is further divided into three subspecies, the Northern, Southern and Eastern rockhoppers, and is the source for much of the debate surrounding the total number of penguin species. They live on small, isolated islands in the sub-Antarctic regions of the Atlantic and Indian oceans.
Rockhopper nesting grounds are on rugged terrain requiring the penguins to hop from rock to rock, the inspiration for their name. The birds can congregate in colonies containing up to , individuals. Breeding season begins in October, eggs are laid by November and chicks hatch 33 days later. The average rockhopper lives 10 years, but they may live as long as 30 years. They feed on krill, small fish and squid. Rockhopper penguins are the only species to jump feet first into the water when they dive.
They stand at 18 inches 46 cm and weigh 5 to 10 pounds 2. Snares Crested Eudyptes robustus -Snares crested penguins live on the isolated and densely forested Snares Islands, a group of small islands roughly 60 miles km south of New Zealand.
They inhabit the most restricted area out of all the penguins and eat squid and small fish. The birds breed under the protection of the Olearia forests in nests of peat, pebbles, and brush beginning in September.
Two eggs are laid a few days apart and hatch between 31 and 37 days later. Snares crested penguins reach sexual maturity at age 6 and may live up to their early 20s. They stand at 22 inches 56 cm and weigh between 6 and 10 pounds 2. Erect-crested Eudyptes sclateri - The erect-crested penguins are best identified by their upright and fanned yellow plumes. Male competition for breeding sites in September is fierce and penguins commonly resort to biting and beating each other with flippers.
The diet of erect-crested penguins is not well known, though it is suspected they eat krill, small fish, and squid like other crested penguins. They stand at 26 inches 67 cm , weigh up to 14 pounds 6. Humboldt Spheniscus humboldti - Native to the hot climate of the Atacama Desert on the coast of South America, Humboldt penguins have large, bare skin patches around their eyes, an adaptation to help keep them cool.
Humboldt penguins dig nests in sand or penguin poop guano where they incubate the eggs for 40 to 42 days. Breeding season is either March to April or September to October depending on the location of the colony.
Humboldt penguins rely on the nutrient rich Humboldt Current to support the anchovy and sardine populations they prey upon. The Humboldt is one of the most popular zoo penguins due to its ability to withstand warmer climates.
They stand at an average height of Magellanic Spheniscus magellanicus - The Magellanic penguin lives along the southern coast of South America from Argentina on the Atlantic side to Chile in the Pacific. Their breast plumage consists of two black stripes that differentiate them from the geographically nearby Humboldt penguin. Magellanic penguins nest in ground dugouts, when possible, or under brush.
Both parents share sitting on the egg for the 39 to 42 day incubation period. During the winter months, between May and August, Magellanic penguins migrate along the coast of Chile, and as far north as Brazil on the East Coast, chasing anchovies. Adults stand at 28 inches 70 cm and weigh up to roughly 15 pounds 6. African Spheniscus demersus - The African penguin is sometimes referred to as the jackass penguin for its shrill braying that sounds like a donkey.
They inhabit the southern shores of Africa from Namibia to South Africa and feed on pilchard, sardines, anchovies, and mackerel. Their nesting colonies are large and noisy. Each breeding couple lays two eggs in a shallow dugout in the ground. Eggs are incubated between 38 to 40 days by both parents. They have a lifespan between 10 and 15 years. At 23 to 25 inches tall Galapagos Spheniscus mendiculus - Galapagos penguins are the most northerly penguins, living along the Galapagos Islands on the equator.
These penguins have special adaptations and behaviors that help them deal with the tropical heat. Galapagos penguins actively seek out shade, pant, stand with wings spread, and hunch over on land to shade their feet, an area of heat loss. Galapagos penguin breeding is completely dependent upon the Cromwell Current and they may breed during any month of the year depending upon seasonal climate conditions.
When the Cromwell Current fails to upwell and bring colder, nutrient rich water to the surface, penguins delay breeding presumably because of low food availability. Once the penguins are able to breed, egg incubation is roughly 40 days.
The Galapagos are the smallest of the banded penguins at 21 inches 53 cm and weigh up to 5. Chinstrap Pygoscelis antarcticus - Chinstrap penguins are distinguishable by their white face and a thin black band that runs across the chin. Unlike many other penguin species, the chinstrap usually rears both chicks to adulthood when environmental conditions are favorable. Beginning in November, adults incubate the eggs in shallow pebble nests for up to five to six weeks.
They prey upon Antarctic krill, Euphasia supurba, almost exclusively but will also eat small fish. At a maximum size of 30 inches 76 and weighing 10 pounds 4. Gentoo Pygoscelis papua - The largest of the brush-tailed penguins, this bird is further distinguished by its red beak.
The gentoo nests on both the Antarctic Peninsula and on sub-Antarctic islands. They construct nests with tussock grass and moss when available but will also use pebbles in rockier environments. Both eggs are incubated for 31 to 39 days. Loyal birds, they not only return to the same nesting site every year but will also form lasting bonds with breeding partners.
Adults subsist on mostly Antarctic krill but will also eat other crustaceans, squid, and fish. Gentoo penguins reach sizes up to 32 inches 81 cm and 15 pounds 6. An ice-dependent species, they rely on the ice for foraging, often trapping prey under ice floes sheets of ice that jigsaw the ocean surface and resting on top of them to avoid predators.
Populations are on the decline on the northern Antarctic Peninsula, where air temperatures significantly increased in the latter half of the 20th century due to climate change. Breeding season begins in October, with eggs hatching after 35 days of incubation. They rely heavily on Antarctic krill but also eat fish, crustaceans, and other krill species.
The birds stand at 27 inches 70 cm and weigh up to 12 pounds 6. Emperor Aptenodytes forsteri - Living exclusively within the Antarctic, emperor penguins are truly animals fit for the extreme.
Breeding season begins at the end of March with couples congregating in one of 45 different colonies along the Antarctic sheet ice. After a quick courtship, females lay a single egg and transfer it to a nest between the feet of the father.
Father emperors battle harsh temperature and wind conditions while incubating the egg. They often lose as much as half their body weight during the process. At a maximum size of 51 inches cm and 88 pounds 40 kg they are the largest penguin species. Adult couples can only afford to raise two chicks every three years because of the extensive time needed to rear one chick. Breeding may begin anywhere from November to April so colonies have a mix of chicks of various ages.
King penguins breed on sub-Antarctic islands within the Southern Atlantic. Standing they can reach heights up to 38 inches 95 cm with weights as high as 35 pounds 16 kg. Yellow-Eyed Megadyptes antipodes - Yellow-eyed penguins are the most private of all penguins, preferring to nest out of sight from other penguins. They often forgo parental duties if they are within eyesight of other nesting couples.
For this reason they often nest among the tree trunks of the dwarf rata forests on the islands off of New Zealand where they are native. The breeding season is particularly long, lasting from August to February. Egg incubation alone can take up to two months. They weigh between 5 and 5. Little or Fairy Eudyptula minor — The smallest of the penguins, the little penguin claims the rocky island coasts around New Zealand and Australia as home.
Colonies are usually at the base of sandy dunes or cliffs. They eat mostly small fish, but occasionally will consume krill and small squid. Little penguins live an average of 6.
Breeding season begins in August and lasts until December. Chicks take roughly 36 days to hatch and then another 3 to 4 weeks where they depend on their parents for food.
Juveniles reach sexual maturity at age three. Emperor penguins are able to cope with this cold as they have the highest density of feathers of any bird species — feathers per square inch! Penguins loose a lot of heat through their feet and flippers, so they have a highly developed vascular system to minimise this heat loss. But, while this prevents the feet from freezing, it also increases the heat loss. To combat this, penguin vascular systems have a counter-current heat exchange system for their extremities.
This works by passing warm arterial blood from the body through fine arteries in close contact with veins returning from the feet and flippers.
The warm arterial blood is cooled before it reaches the extremities, while the returning blood is warmed before it can chill the body. These adaptations work so well that they can actually cause penguins to overheat in areas of higher temperatures. So species in warmer places like South Africa have large flippers and bare areas on their faces.
Scientists can undertake population counts of penguins in inaccessible areas by using high-resolution satellite imagery. They are able to differentiate between birds, ice, shadow and guano penguin poo. Adult emperor penguins are 1. The smallest species is the blue penguin also known as the little penguin or fairy penguin at just over 0.
One extinct penguin species, known by the scientific name of Anthopornis nordenskjoldi , was even larger than the emperor penguin, standing an impressive 1. Many bird species are adapted to flying by having hollow bones, whereas penguins have dense bones, which makes diving easier. Penguins can dive to depths of over m, although most dives will be within the top 10m of water. The deepest dive ever recorded is by a female emperor penguin that dived to m below the surface!
Gay penguins were first observed over a century ago by the British explorer George Murray Levick, who documented extensive homosexual sex between Adelie penguins. He also recorded other unexpected sexual behaviour that was deemed too shocking to become public knowledge at the time. To avoid anybody but educated gentlemen becoming aware of his discoveries, he wrote the more controversial parts in Greek. Since then, gay penguins have been documented across several species, with widely publicised accounts of homosexual penguin couples in zoos successfully raising adopted chicks.
Leopard seals, sea lions and orcas killer whales will all eat penguins, although leopard seals are usually the biggest threat in Antarctica.
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