Swift, swallow, or house martin? Which is it?

The RSPB's Rupert Masefield describes how you tell apart swifts, housemartins and swallows ... 

I love seeing these amazing fliers hunting their insect food in the air above houses, meadows and lakes, but for an amateur like me it’s not always easy to tell at a glance which one it is you’re looking at – especially on a sunny day when all you can make out is a blurry silhouette. I hope this blog post will help people out there like me (enthusiastic but clueless) more easily tell the difference between them, and maybe share a few fascinating titbits of information while we’re at it.

And if you’re thinking about going out in search of swallows, swifts or house martins, here’s some inspiration in my blog about searching for the first swallow of the spring.

What they have in common

Swifts, swallows and house martin do all share some things in common, but while house martins and swallows are close cousins in the same family of birds, swifts are only superficially similar and not actually closely related. They are all proficient fliers and feed by hunting insects on the wing, catching and eating them in mid-air, and are all gregarious and sociable. They are roughly similar in size and shape, hence the difficulty some people have telling them apart, and swallows and house martins build similar nests, but it is their differences and how to tell them apart that we’re really interested in here.

[Use individual photos of swift, swallow and house martin with their entries below]

Swallow

The most obvious thing that distinguishes swallows is their deeply forked tails. These tail streamers are shorter in younger birds though, and not always easy to see in the glare of the sun. So, what else can we look out for? Well, they have pale whitish undersides and are uniformly dark blue-black above, and they have a rufous (reddish) chin and throat.

Flight

They are also the most graceful in flight compared with swifts and house martins. They hunt for flying insects low over meadows, rivers and lakes, often swooping to scoop up a beak-full of water.

Call

A joyful chirruping gurgle, or sharper cheep if alarmed.

Nesting

Make cup-shaped nests out of mud, frequently using old barns or outbuildings. And they do land. You might see them perched on overhead wires or even on the ground when they are gathering nest material.

Location

You’re much less likely to see a swallow in a town or city the swifts, or even house martins. Swallows are definitely countryside lovers.

Time of year

Swallows, house martins and swifts are all migratory birds that spend the winter in Africa. Swallows and house martin arrive back in the UK in late March to early April and leave again in September to October.

Fun fact: Swallows’ long forked tail isn’t just for show, it helps them manoeuvre in the air.

rspb.org.uk/swallow

House martin

House martins are smaller than swallows. They have only a shallow forked tail and lack tail streamers. Their body is all white beneath with bright white chin and throat. The white patch on their rump on their otherwise blue-black back and head is a great way to single them out in a mixed flock with swallows. Their wings are short and pointed and wider than a swallow’s, and their bodies less slender – they are more torpedo than an arrow! 

Call

Soft chirp chirp, without the burbling of a swallow.

Nesting

Like swallows, house martins make cup-shaped nests from mud, most often under the eaves of houses – hence their name – but unlike swallows, they nest in colonies.

Location

House-martins are as happy in suburban and even urban areas as they are in the countryside. As long as there is somewhere for them to make their nests, mud for building, and plenty of food, you might have house martins near you.

Time of year

Like Swallows, house martins arrive in March-April and leave again in September-October.

Fun fact: They often form mixed flocks with their cousins the swallows (and even closer relatives the sand martins) and migrate together.

rspb.org.uk/house-martin

Swift

Swifts are larger than swallows and a uniform sooty brown colour, but often look black against a bright sky. They spend half of the year on the wing moving between their wintering and breeding grounds, and they are supremely well adapted to this lifestyle. Their long narrow wings give them a scythe-like appearance in the air, with their diminutive bodies seemingly hanging from a single aerofoil.

Flight

Swifts appear to be “all-wing” and their behaviour is similarly all about being in the air.

Nesting

Swifts nest in colonies. Partners pair for life and return to the same nesting sites year after year. Nests are most often cavities in buildings and usually higher above the ground than those of house martins or swallows.

Location

Swifts can be spotted in aerial hunting parties catching flying insects and airborne spiders in towns and cities, where there are plentiful nesting opportunities, but can also be seen throughout the countryside.

Time of year

Swifts are some of the last summer migrants to arrive in this country and among the first to leave again in the autumn, meaning you have to makes the most of enjoying watching their aerial acrobatics between May and September.

Fun fact: Swifts have the shortest legs of any bird relative to their body size and can’t take off from the ground. Their scientific name, Apus apus, even means “without feet”.

rspb.org.uk/swift