Swift, Swallow or House Martin? by Catherine Day

  • This is a summer dilemma that many people have. More and more swifts are arriving as May progresses, so now is the time to practise your ID skills! 

    The easiest of these summer visitors to identify is the Swift; partly because a Swift is…. well, just that: swift!  It is, in fact, the fastest bird on the planet in level flight, hence its name.  

    Apart from its speed, here are the other main ID characteristics of the swift that we see in Britain – the Common Swift (Apus apus):

    - Swifts are all brown, except for a small, pale patch under their chins, (this is usually invisible in flight). They have no large areas of white on them.
    - Swifts have much longer wings than swallows and martins.
    - Swifts have elegant, long, tapered, crescent-shaped wings (sometimes described as sickleshaped, scythe-shaped, or boomerang-shaped). Swallows and martins have stubbier, triangular-shaped wings.
    - Swifts are bigger than swallows or martins, (though this is sometimes hard to tell this when the birds are high in the sky).
    - Swifts have a call that is an exuberant scream. Swallows and house martins have a much more twittery sound.
    - When they are in flapping-flight mode, swifts have a flickering wingbeat, not unlike a bat, if you were to see both at dusk.
    - At virtually any time on beautiful. warm, sunny, summer days, especially in the two hours before nightfall, swifts enjoy zooming and swooping above and around buildings in excited, high-speed ‘screaming parties’, often circling round and round several times, then separating, then gathering again for another screaming display. They are the summer’s ‘Red Arrows of the bird world’! 

    Another way to tell if you are seeing a swift, rather than a swallow or a house martin is to ask yourself these questions:

    ? Is the bird perched anywhere (such as on a wall, roof, wire, tree)?  If it is, then it’s not a swift! 
    Swifts are not perching birds – they never perch anywhere. However, they can cling briefly to vertical surfaces as they climb up into their nest holes. Otherwise, they spend their entire lives in the air.

    ? Has the bird got any significant areas of white, or other colour on it? If it has, then it’s not a swift!
    Swifts are dark all over, apart from a very small pale area on their chins (just under their beaks).  Swifts are, in fact, all-brown birds, but often appear black against the light as they swoop and zoom about the sky. Swallows have buff underparts, blue reflections on their backs and red faces; martins have white underparts.

    ? Is the bird twittering or making little chirping calls?  If it is, then it’s not a swift!
    Swifts have an exuberant ‘scream’ as their call, especially when they are zooming about in groups. If you listen carefully, however, and they are relatively close to you, you might also hear a few brief repeated ‘chirrups’ as they speed past, a bit like quick-fire little bursts of shrill, highpitched, very fast referee’s whistle. Their most distinctive call, though, is the excited ‘scream’.

    ? Has the bird built a visible mud nest?  If so, then it’s not a swift!

    Swifts’ nests are never visible and they do not make nests out of mud. Instead, they build their nests out of sight, hidden well away inside dark nooks and crannies high up in the eaves or roofs of buildings.
    Swifts’ nests are minimalist – small, flat, saucer-shaped nests made of feathers and bits of grass that they find flying around in the air. Swallows and house martins make mud nests.

    And a note on tails to finish with:
    All these species have forked tails, but the swallow is the one with the distinctively-long tail streamers. 
    The swift can close its tail to a single point, or hold it in a smallish fork. It will also stretch its tail feathers out into a wide fan in order to change direction in the sky, or to act as a brake when it flies up to its nest hole and needs to reduce speed extremely rapidly.

    Here are some links to websites to help with identification of swifts, swallows and martins




    And if you see a Swift in your area, please help them by reporting your sighting to the RSPB Swift Mapper:


    Swifts are not related to swallows and martins. Swifts belong to the Apodidae family, whereas swallows, house martins and sand martins are all Hirundines (i.e. of the swallow family).

    Catherine Day,  RSPB Swift Volunteer, Wild Marlow
    May 2020

    Blog Image