Class: AVES

Order: SPHENISCIFORMES

Family: SPHENISCIDAE

At this bird garden in England, King and Humboldt Penguins co-exist. Whilst they would never meet in the wild, the cohabitation here has been successful for years, and the penguins are perhaps the most popular birds in the park. The King Penguin is the second-largest Penguin species, some hundred centimetres shorter than the Emperor Penguin.

This group contains sea-bound birds, almost entirely found in the southern hemisphere. The penguin has diverged into six major genera, all representatives, bar one, are native to the southern hemisphere. The largest penguin, the Emperor Penguin, stands at a metre and a half tall, but the smallest of all, the little penguin, only stands at a mere 30 centimetres. Most penguin species lie around the middle of this. Smaller penguins prefer habitats where rocks and stones are abundant, and some of these dig burrows. The largest penguins are too large to dig burrows, and are largely terrestrial, occasionally aquatic birds.

These penguins are aptly-named 'little penguins', and are the smallest penguins in the world, at only 30 cm in height. With bluish feathers, they have good camouflage in water.

Exactly where the penguin fits into bird classification is rather debated, and so there is a fair amount of speculation as to what exactly the penguins evolved from. However, the oldest known penguins are some 62 million years old, and perhaps looked more like straight-beaked cormorants than modern penguins. Originating around New Zealand, they would soon move throughout the southern hemisphere, and produce a variety of different builds. The largest penguins to ever live grew to almost 2 metres in height, living some 35 million years ago, but 25 million years ago, these would disappear. Today, there are six genera of living penguins - the genus Aptenodytes contains the 'great penguins' - the king and emperor penguins, which are considered most similar to the original penguins. The penguins of genus Pygoscelis are occasionally known as 'brush-tail penguins' for their relatively long tails. The penguins of genus Spheniscus are known as 'banded penguins', and all have similar patterning. Penguins of genus Eudyptes all look relatively similar, with vivid yellow crests, and orange beaks. The smallest penguins belong to the genus Eudyptula, which only grow to about 30 cm in height, aptly named 'Little Penguins'. There is only one living species in the genus Megadyptes, the Yellow-eyed Penguin. Of all penguin species, only one has become somewhat native to the Northern hemisphere - as the Galapagos Penguin's range extends northwards.

Here are three more penguin species. From left to right, the Gentoo Penguin is mostly found on islands surrounding Antarctica. This Rockhopper Penguin appears to be molting, in other times of the year, its skin will be more sharply coloured. And the African Penguin is occasionally known as the 'jackass penguin', for its braying calls, similar to that of a donkey.