Fossil records show that there were at least 25 species of penguin in the past, several of which have gone extinct.
Where do penguins live?
Everyone imagines penguins on the ice in Antarctica or taking a break on a passing iceberg, but penguins are also found in South Africa, Chile, Peru, Galápagos Islands, New Zealand, Australia and a number of sub-Antarctic islands.
Penguins are very nearly exclusive to the southern hemisphere, but Galapagos penguins live right on the equator and so there are a few penguins living in the northern hemisphere.
The name penguin was originally given to an unrelated bird species – the now-extinct great auk, which was a large, flightless, black and white bird. When explorers first encountered wild penguins, they used the same name for the new creatures they were seeing.
Yes, penguins are birds. Lots of people think penguins are mammals rather than birds because they can’t fly, and we see them swimming underwater or waddling on land instead. But there are other birds that can’t fly (like emus, ostriches and cassowaries), and penguins fulfil all the biological requirements to be classified as birds – they have feathers, they lay eggs and they’re warm-blooded. They’re just seabirds that are very well adapted to their unusual lives, which is why they’re so different from other birds.
Yes, penguins have feathers just like all other birds. Penguin feathers are shorter and stiffer than most bird feathers, which makes penguins more streamlined in the water and traps more air to provide better insulation.
Penguins do have knees, you just can’t see them hidden away under all those fluffy feathers. They don’t even have particularly short legs, so why do penguins waddle?
Scientists think it’s because penguin legs have evolved to help them swim more efficiently, which has resulted in them being set further back on the body than you might expect. That makes walking more difficult, and the classic penguin waddle is the result.
How do emperor penguins keep warm during the Antarctic winters?
The emperor penguin is the only species that spends the harsh Antarctic winter on land – the males protect their eggs from the cold ice by keeping them on their feet. The females are off at sea during much of this time.
Emperor penguins are able to cope with this cold as they have the highest density of feathers of any bird species – 100 feathers per square inch!
Penguins lose a lot of heat through their feet and flippers, so they have a highly developed vascular system to minimise this heat loss.
When the ambient temperature falls below 0˚C, a penguin increases the circulation of warm blood to its feet. 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.
How do scientists count penguins?
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 1.2m tall, which makes them the tallest penguin species. The smallest species is the blue penguin (also known as the little penguin or fairy penguin) at just over 0.3m tall – 4x shorter than emperor penguins.
The fastest species of penguin is the gentoo penguin, which can swim at up to 22mph.
Are there any gay penguins?
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.
What do penguins eat?
Penguins eat a variety of seafood such as fish, squid and crustaceans. The smaller penguins usually feed on krill.
Climate change is likely to affect the numbers of krill, and thus affect the penguins as well. Since the 1970s, krill density in some areas has decreased by 80 per cent.
Leopard seals, sea lions and orcas (killer whales) will all eat penguins, although leopard seals are usually the biggest threat in Antarctica.
Penguin chicks and eggs aren’t safe either, with skuas hanging around penguin colonies to pick off any young left unattended.
How are penguins adapted to saltwater?
Due to eating so much seafood, penguins need to be able to cope with the high amount of salt in the saltwater. They have a gland located just above their eye called the supraorbital gland, which filters the salt from their bloodstream. This is then excreted through the bill, or by sneezing!
Sadly all penguins are flightless, although the BBC did trick a lot of us on April Fool’s Day a while back.
Do penguins moult?
Penguins undergo a process called catastrophic moulting, when they replace all of their feathers in the space of a few weeks. During this time, they cannot enter the water so they need to have accumulated enough fat to fast through this period. Most birds replace their feathers gradually over the course of the year, while penguins have to go through this process all at once.
What species are penguins most closely related to?
A penguin’s closest relatives are petrels, albatrosses and divers.
British Antarctic Survey (BAS), an institute of the Natural Environment Research Council (NERC), delivers and enables research in the Polar Regions with staff based in Cambridge, Antarctica and the Arctic, to advance our understanding of Earth as a sustainable planet. Find out more about their work: www.bas.ac.uk