Penguins~

Adelie Penguin (Pygoscelis adeliae) feeding young. Like its relatives, a neatly bi-coloured species with a head marking.

Penguins are a group of aquatic, flightless birds living almost exclusively in the southern hemisphere, especially in Antarctica.
Highly adapted for life in the water, penguins have counter shaded dark and white plumage, and their wings have become flippers.
Most penguins feed on krill, fish, squid, and other forms of sea life caught while swimming underwater.
They spend about half of their life on land and half in the oceans.
Although all penguin species are native to the southern hemisphere, they are not found only in cold climates, such as Antarctica.
In fact, only a few species of penguin live so far south.
Several species are found in the temperate zone, and one species, the Galápagos Penguin, lives near the equator.
Penguin may come from the Latin pinguis, “fat”.
This is supported by the fact that the corresponding words in most other languages (e.g., French pingouin, German Pinguin) have i instead of e as the first vowel.
What may be a King Penguin but certainly is a member of the Spheniscidae appears on a 1599 map at the Strait of Magellan with the caption "Pinguyn".
The map's features are labeled in Latin, such as Fretum Magellanicum ("Strait of Magellan").
In addition, there is ample evidence that the Latin term anser magellanicus ("Goose of Magellan" or "Magellanic Goose") was the usual term for penguins in the scholarly literature of that time.
As a side note, the French pingouin actually translates to English as the Auk, as penguins are called manchot in French.
The word Penguin is thought by some to derive from the Welsh words pen (head) and gwyn (white), applied to the Great Auk which had white spots in front of its eyes (although its head was black); or from an island off Newfoundland known as Pengwyn, due to its having a large white rock.
(In the latter case, the name may also have come from Breton.)
This fanciful theory is highly unlikely, since penguins do not actually have white heads, and there are no other examples of a Welsh word becoming the basis of words throughout Europe languages.
Welsh was not even spoken in England, let alone throughout Europe. Furthermore penguins have no particular link to the Welsh which would lead foreigners loan a word from Welsh.
A Welsh i is often sound-shifted to an e in the English language.
Another theory states that the word is an alteration of “pen-wing”, with reference to the rudimentary wings of both Great Auks and penguins, but there is no evidence to support this.
In a final twist to the story, the term "Magellanic Goose" (today usually "Magellan Goose") in our time has come to denote an actual anseriform, namely a Chloephaga sheldgoose. Penguin ancestry beyond Waimanu remains unknown and not well-resolved by molecular or morphological analyses.
The latter tend to be confounded by the strong adaptive autapomorphies of the Sphenisciformes; a sometimes perceived fairly close relationship between penguins and grebes is almost certainly an error based on both groups' strong diving adaptations, which are homoplasies.
On the other hand, different DNA sequence datasets do not agree in detail with each other either.
Humboldt Penguins in an aquarium. The penguin is an accomplished swimmer, having flippers instead of wings.
What seems clear is that penguins belong to a clade of Neoaves (living birds except paleognaths and fowl) which comprises what is sometimes called "higher waterbirds" to distinguish them from the more ancient waterfowl.
This group contains such birds as storks, rails, and the seabirds, with the possible exception of the Charadriiformes.
Inside this group, penguin relationships are far less clear.
Depending on the analysis and dataset, a close relationship to Ciconiiformes or to Procellariiformes has been suggested.
Some think the penguin-like plotopterids (usually considered relatives of anhingas and cormorants) may actually be a sister group of the penguins, and that penguins may have ultimately shared a common ancestor with the Pelecaniformes and consequently would have to be included in that order, or that the plotopterids were not as close to other pelecaniforms as generally assumed, which would necessitate splitting the traditional Pelecaniformes in three.