When Linnaeus classified the bird in 1758 he gave her two synonymous names: Strix scandiaca and Strix nyctea. However, reasearch in the 20th century made it necessary to revise the traditional classification, as it was found that the snowy owl had little in common with the Strix family. Instead it was named Nyctea scandiaca and thought to belong to its own family. But in 2003 DNA comparisons showed that the snowy owl is closely related to the eagle owl (Bubo bubo) and was thus renamed Bubo scandiacus.
The snowy owl has big yellow eyes and a wing span of 140-165 cm. Males are smaller and normally completely white, while females are speckled with black. It’s a nomadic bird. It migrates not only for reproduction purposes, but due to fluctuations in the populations of its prey species. So it happens that sudden invasions of snowy owls are observed by ornithologists in more southerly regions. The winter 1999-2000 saw one such invasion in Sweden, and William Leon Dawson describes large invasions in Ohio in 1926-27 and 1930-31:
In 1926-27, 92, or 67 per cent, of the birds reported were killed or captured while in the recent invasion only 51, or 40 per cent, suffered the same fate. This, perhaps, is largely due to the fact that the height of the migration came nearly a month later in 1930-31 or mostly following and not during the hunting season. Also, in 1926-27 most of the birds reported appeared to be in a somewhat dazed condition and not at all at home in their new environment. Many were absolutely without fear and others appeared sick. Numerous birds at that time were captured by hand, flying into automobiles or attracted by bright lights. A number were struck down by railroad locomotives, picked up while in an exhausted condition or found in some unusual situation which hardly seemed a logical stopping place for a normal bird of prey. Of eleven stomachs examined by the writer at that time, ten were entirely empty while one contained a small quantity of chicken feathers. Nearly all birds handled were considerably emaciated. In 1930-31 records of birds taken under unusual conditions were very few. Most birds captured or observed appeared normal in every respect and not dazed or emaciated but as much at home as our native owls. This undoutedly accounts for a much lower percentage of the birds being killed or captured and leads me to believe that in Ohio, and perhaps elsewhere, the 1930-31 invasion did approach that of Snowy Owl Invasion of Ohio in 1926-27 in numbers much more closely than the figures actually reported would indicate. In 1930-31 a large number of the records listed were of birds reported to have been present in some particular locality for from two to nine weeks, the birds being observed almost daily hunting over stubble fields or bottom lands where meadow mice were abundant. All observers questioned were of the opinion that certainly a large percentage of the birds of this recent invasion did succeed in returning to northern regions in the spring, escaping the tragic fates of most of the owls of 1926-27. Of nine stomachs examined in 1930-31, all but one contained some food, including two Bobwhites, parts of a Ringnecked Pheasant, a sparrow, remains of a Hungarian Partridge, one rat, bits of two chickens, and eight mice.”
