Chapter 3 of 23

What a Barn Owl Looks Like

Colour, size and how to tell males from females

About 6 minute read

A Barn Owl is a medium sized owl, a little longer than a foot from head to tail, with wings that stretch to around a metre across when it is in the air. It looks bigger than it is. The soft, deep plumage makes it seem chunky when it sits, and the long wings make it seem huge when it flies, yet the bird itself is remarkably light, usually around the weight of a small bag of sugar.

Female Barn Owls are a bit bigger and heavier than males. A typical male weighs about 300 g and a typical female about 360 g, which makes her roughly a fifth heavier. In the breeding season she gets even heavier, because she puts on weight before laying and can reach about 425 g when the first egg arrives. Then she slims down again over the weeks she sits on the eggs.

Colours and patterns

The upper side of a Barn Owl is a lovely mixture of golden buff, soft grey and white. If you look closely at a single feather, the pattern is quite simple. Each feather is buff, and towards the tip it has a pair of small flecks, one dark brown and one greyish white, along with a delicate grey pencilling. It is the combination of thousands of these tiny marks that gives the back its speckled, misty look.

The underneath is white, sometimes with a wash of buff, and often with a small scattering of dark spots. The wings and tail are barred with buff and brown, and the underside of the wings is white with the odd fleck, which is why a Barn Owl looks so pale when it flies over you at night.

The face is white with a patch of reddish brown in the corner of each eye and a rim of stiff feathers around the edge that may be white, buff or dark tipped. The eyes are dark hazel, so dark that they look black. The bill is pale, a little straighter than the bill of most owls and pointed more downwards. The legs are covered in short white feathers and the toes are bare or bristly. The colour of the toes varies quite a lot between individuals. They may be a dull greyish brown or a bright yellow underneath, and that is a handy clue when you are trying to recognise one bird from another.

How much do they vary?

A lot. Barn Owls range from very pale, almost white birds to richer, deeper buff ones. Lightly marked males can look pure white from a distance, especially when they are flying and the light catches the underside of the wings. Darker females look more golden or even brown, and from far off can look surprisingly like a Short eared Owl. This variation is really useful to people who watch them closely, because it helps them recognise individual birds over the years.

The white front might seem an odd choice for a night hunter. Most owls wear bark coloured feathers so that they blend into the trees. A Barn Owl, though, nests and roosts in dark holes and buildings, where it does not need to hide from anything, and a pale body may even help a pair spot each other in very dim light. Females, which sit on the nest for weeks, tend to be a bit darker, which may make them a little less obvious.

Telling a male from a female

You will not find a bird that wears a label, and sexing Barn Owls by sight alone is never simple. The best approach is to gather several clues and see which way they point. Here are the ones I find most useful.

• Size and weight. Females are around a fifth heavier, but it is hard to judge unless the pair stand side by side.
• The facial disc. A female often has a slightly darker brown rim of feathers around her face, though the difference can be subtle.
• Overall colour. Females tend to be a little darker and richer, while males are usually paler with a cleaner white chest.
• The buff scarf. A female often has a buff coloured patch over her throat, where a male's throat is whiter. In natural daylight it is easier to see than on a nest camera.
• The spots. Females tend to have small flecks or spots down the flanks and sometimes across the chest. Males usually have plainer white plumage, although they can have a few marks too.
• The tail. A female's tail feathers are usually slightly darker.
• Behaviour. During courtship, the female often does more of the preening. Once the eggs are down, the bird sitting on them is the female and the bird bringing food is the male.

The really important thing is not to rely on one clue. A very white chested owl may still be a female. I once watched two females that had almost no spots on their chests, but they had a few flecks on their flanks, a buff throat and a slightly darker look overall. Both spent a lot of time fussing over and preening a smaller male, and when eggs turned up in the nest box, that settled the question.

My full guide, with photographs, is on the website: How to tell the sex of a Barn Owl.

Young Barn Owls

A newly hatched owlet is almost bald and pink, but within a day it grows a coat of short white down. A few weeks later a second, thicker and fluffier coat replaces it. Owlets do not have a separate, streaky juvenile plumage like many other birds. Instead the adult feathers grow through the down, and by the time they are around ten weeks old, they look very much like their parents. You can still tell them from adults for a while, because they sway and bob their heads more, and they still have some fluff on their heads.

A slow moult

Like every bird, a Barn Owl has to replace its feathers, and it does so once a year. Because a Barn Owl hunts by flying slowly and silently, a gap in the wing would spoil the whole hunt, so the big wing and tail feathers are replaced a few at a time over many months, starting somewhere near the middle of each wing and working outwards in both directions. Some females start to moult while they are still sitting on the eggs, so it is quite normal to find large feathers in a nest. Males often start after the young have hatched.

The moult takes a long time and can be hard to follow, and some old feathers stay on for a surprisingly long time. By the end of the breeding season, a busy male can look rather scruffy, and his colours may look a little faded from all the wetting and drying in long grass.