Owls are not usually considered dangerous, but the first thing you have to remember is that there are so many different species of owl and they vary enormously in size and behaviour. The largest owl in the world is Blakiston’s fish owl, a very rare bird that is only found in parts of Russia, and a few areas of China and Japan, and perhaps North Korea. The fish owl is as large as a child; it can be 70 cm tall and has a wing span of two metres or 6 feet. So a bird that size might be able to attack a person, or a child at any rate, but in fact this is extremely unlikely because these owls are so very shy. They are rarely seen at all, let alone feared (except by other birds and animals of course – they are excellent hunters).

However, there are other owls, smaller but still large enough to be reckoned with, that have attacked humans. In the US, for example, there have been several cases of hikers being attacked and injured by barred owls. This bird is smaller than the fish owl or the better known eagle owl – its wingspan is up to about 4 feet – but it is a fierce fighter, and because its approach is silent it can come up on you unawares. The barred owl tends to go for the head when attacking, and some people in Texas got some quite nasty injuries from owl attacks as recently as 2007. The Arctic dwelling snowy owl is a similar size but rather heavier, and though unlike the barred owl it is very unlikely to attack unless its nest is disturbed, it will defend the nest by striking with its talons.

It seems that more incidents of owls attacking humans have been recorded in the last few years than before. Whether this is because humans are coming closer to their nests, or the owls are getting used to people and losing any fear of them, is not sure. Generally, females are more likely to attack than males, especially if they have young to defend (this is true of many birds) and young owls that have just left the nest can be aggressive too. So spring is often the worst time to go too near the habitats of large owls.

This should be put in perspective though – you are very unlikely to be attacked even by a large owl unless you disturb its nest, and even in these cases the injuries received haven’t been major ones. There are birds that can be really dangerous to humans – the Australian Cassowary is reckoned to be the most dangerous of all – but owls aren’t among them. But like all birds of prey, owls big and small are fiercely territorial, and like animals everywhere they will do whatever they can to protect their young – so it’s not really surprising if an owl that has its home disturbed should beat its wings and threaten any intruder with its talons. In nearly all cases, if you just move away the owl won’t follow you.

At the other end of the scale, the Elf Owl is usually less than 15 cm or 6 inches long, though some can grow to 30 cm. The Northern Pygmy Owl rarely grows beyond 18 cm. This last little owl is very fierce, and if it was big enough it probably would attack you, but due to its tiny size it has to make do with mice and other small creatures.

You can read a story about owl attacks on humans here.