Telling swifts from swallows, in flight

If like me, you’ve wondered if that is a swift or a swallow flying overhead, this may help. I pulled out the differences from online sources, and then cross-checked them with The Book of Indian Birds (Salim Ali, Thirteenth Edition). Guess what. There are enough exceptions to shoot some of these rules out the window. Here it is anyway, for what it is worth.

To begin with, pulled these silhouettes, from here:

Swallow:

Swift:

The swallow:

• Has a deep forked tail, often with long streamers (does not apply though to the house and streak-throated swallows)
• Has broad wings, relatively
• Has a white or light coloured underside
• Has a rusty red chin patch (the common swallow only)
• Is passerine, can and does perch
• Builds nests of mud and straw

The swift:

• Has a slightly forked tail though not as deeply forked as the swallow’s (exceptions: crested tree-swift and Asian palm-swift)
• Has long narrow swept-back wings resembling a crescent or scythes
• Is dark brownish all over with a pale throat
• Calls noisily while flying
• Clings with tiny weak legs, cannot perch
• Breeds in holes and crevices of old buildings

Post Script: While on the topic, don’t miss this most delightful piece of verse by rickyengland:

HOLLOW VICTORY

The fly flew over the meadow

A Swallow he followed the fly

‘I’ll fly’, said the fly, ‘to the hollow’

‘For the Swallow is swifter than I’

Too soon did the triumphant fellow

Let out his victory cry

For there on the edge of the meadow

A Swift did swallow the fly

References:

http://www.bbc.co.uk/nature/22527420

http://www.rspb.org.uk/wildlife/birdguide/name/s/swift/identification.aspx

http://www.naturalenterprise.co.uk/pages/news/46-have-you-seen-a-swift