Gearóid Mac Niocaill’s book Ireland before the Vikings (Gill and Macmillan, 1972) has an interesting passage on the names adopted on the island during the 4th, 5th and early 6th centuries. He refers to “a mosaic of peoples” who are “dimly perceptible” amid the settlements and political changes he has been discussing, and whose names appear in various forms:
ending in -raige (‘the people of’), or as Dál (‘the share of’) or Corco (perhaps ‘seed’) plus a second element, or as a collective noun ending in -ne. Some contain animal names, such as Artraige ‘bear-people’, Osraige ‘deer-people’, Grecraige ‘horse-people’, Dartraige ‘calf-people’, Sordraige ‘boar-people’; others, such as the Ciarraige, the Dubraige and Odraige, have a colour (ciar ‘black’, dub also ‘black’, odor ‘dun’) as the first element; others, such as the Cerdraige, seem to have an occupational term as the first element.
A similar list appears in Macalister’s Ireland in Pre-Celtic Times, which mentions Corcu Bibuir ‘beaver people’, Corcu Cuilend ‘puppy people’, Corcu Oirce ‘pig people’, Corcu Tened, ‘fire people’; Bibraige ‘beaver people’, Boccraige ‘goat people’, Breccrige ‘trout people’, Cattraige ‘cat people’, Cechtrige ‘plough people’, and Cnamrige ‘bone people’.
[Gearóid Mac Niocaill writes that Bibraige, if its purported derivation from 'beaver-people' is correct, “must derive from a remote continental past” because the beaver “is not known in Ireland”. But it used to live here, as far as I know.]
According to Macalister, totemism existed in Ireland “as elsewhere in antiquity”, and he says “the grotesque story that the mother of Oisín the poet was a deer can best be explained by supposing that she belonged to a fawn kindred”. Perhaps; metamorphosis is rife in myth in any case. Oisín, incidentally, means ‘little deer’ or ‘young deer’.
Simeon Potter, in Our Language, notes that people were often likened to animals and birds, and that to the early Germanic peoples
the bear and the boar were the kings of the forest, whereas the wolf and the raven were the close companions of the god Odin. These four creatures figured prominently in personal names throughout Western Europe for many centuries after the Heroic Age.
Back with Ireland before the Vikings:
All these [peoples], when the genealogists got to work in the comparatively Christian atmosphere of the seventh century, were endowed, or endowed themselves, with ancestors whose names included the first elements of their names, or had an etymological explanation provided for them, as with the Cerdraige, of whom it was alleged that every man was a craftsman (cerd). It seems indisputable, however, that one element in these names is in fact the name or epithet of a divinity which that people had in common – ‘the god by whom my people swear’, as the law-texts put it. One such people, the Boandraige, have as the first element of their name that of the goddess Boand, who elsewhere appears as the divinised river Boyne; another, the Luigne, contains the name of the god Lug. Whether such a divinity was regarded as being also an ancestor, which would make easier their transformation by the genealogists, is not clear.
This is not a subject I’ve ever studied in depth, but I find it interesting. Many contemporary surnames are occupational names long divorced from direct implication of a vocation or avocation, or they retain some other form of fossilised cultural meaning. The connection may no longer hold but the name preserves a tenuous link with the remote past.