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]


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.


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.


A joyful chirruping gurgle, or sharper cheep if alarmed.


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.


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.

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! 


Soft chirp chirp, without the burbling of a swallow.


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.


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.


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.


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


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.


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”.

  • Hi Emma. this post was really helpful.

    I've been watching forked-tail high flyers overhead over the past few days of warm weather, in groups of 3 to 6. Our common green backs on to the Meadows in Edinburgh, which is likely to be insect heaven for flying feeders right now. It's such a joy to watch.

    I'm nearly sure they are swifts. I briefly saw what appeared to be the same species of  bird (two together) mid-April.

    I got a couple of photos today. They're not great. But I think they may help confirm the swift identification. Unfortunately I don't seem to be able to post them here as they are not uploaded to the web.

    I've only become interested in birds in more than a passing sense since January this year. And I'm utterly amazed at what I have discovered in such a short time.

    Anyone have any tips for capturing birds in flight? (Other than high shutter speed and lots of patience!?)

    Happy bird observation!

  • Thanks for this information. I have a pair of birds building a nest on my house and now I may just be able to decide what they are, swifts, swallows or martins. I will need to watch very closly to decide which type I have.

  • When I see these birds flying, I feel so relaxed and I can feel the freedom especially when doing turf installation. 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.