A is for Apus

                 Common Swift (Apus apus)

This bird is such an accomplished flier it has earned the adjective “Swift” as its common name and Apus apus , greek for “no foot” as its scientific one, since it does not land from the day it fledges. It is often confused with the swallow but is in fact completely unrelated, being closer to nightjars and  owls *and so are a great example of convergent evolution.  Not to mention the swallow’s aerial abilities pale in comparison. No self-respecting swift would be seen perching on a telephone line. They eat, drink, sleep and mate in the skies, spending most of their life far above in the open air but also moving at incredible speed  kamakazi-style between buildings and other obstacles ( I even witnessed one vertically-slaloming telephone wires!) . They are the peak of avian adaptation to the skies. Healthy adult swifts are so un-catchable they only have two predators in the British Isles, both falcons; The hobby Falco subbuteo, swift-like in itself and a famed dragonfly catcher, and the peregrine Falco peregrinus, which includes swifts as a significant part of its diet in urban areas¹. For some footage of a hobby catching a swift, see this video. The catch is at 04:15.

The swift’s body is well adapted for life on the wing, with stiff sickle-shaped wings making them resemble little, dark aeroplanes and forked tails giving them great steering. Their wide mouths simply scoop up the ‘aerial plankton’ of tiny flies, beetles, wasps, aphids, thrips and money spiders ^ᵻ as they speed along. They do have tiny feet which tuck under their feathers like a plane’s undercarriage, but with sharp curved claws for gripping onto the vertical surfaces such as walls and cliffs where they nest. Their four toes are oriented with one pair facing forward and the other backward(known as zygodactyly), a feature which they share with their hummingbird, nightjar, and owl relatives.

As a late migrant to Britain, the coming of swifts (for me at least) epitomises the summer.  The screeching of males in high-speed chase of a female and their mass flocks around gluts of insects like flying ants are familiar sights and easily observable in urban areas where they temporarily fill the skies with activity.

You might think that such a master of the air, which has adapted to our urban habitats, would be unaffected by people. Unfortunately the swift’s Achilles heel is the need to nest in high, inaccessible crevices which are decreasing as old buildings are levelled or repaired, whilst new buildings often have no suitable nest sites. Coupled with this are the unknown problems in Africa facing many of our summer migrants, perhaps caused by climate change. You can help solve the former problem simply by installing a ‘swift box’ on your property, which can be bought or made from instructions which are available online. In addition, try and encourage authorities  to install them on existing and/or planned buildings in your area. Whatever you do, be sure to visit Swift Conservation for more information and/or to donate to the noble cause of saving Britain’s swifts.

I hope that this unorthodox entry for the letter ‘A’ has boosted your appreciation of this amazing British bird and inspired you to gaze up at the skies this summer.

*In fact, hummingbirds evolved from a swift-like ancestor, becoming accomplished fliers in a very different way.  The resemblance is clear if you compare them and think about the hummingbird with the beak trimmed. They were probably originally attracted to flowers by feeding on pollinating insects, which they still do alongside nectar-drinking.

^ᵻ  Those tiny black ones that inextricably get caught in your hair, actually parachute through the air on long lines of silk.

References

¹Edward J. A. Drewitt and Nick Dixon (2008). Diet and prey selection of urban-dwelling Peregrine Falcons in southwest England. British Birds Available from: http://media.wix.com/ugd//1ab07f_c7e226ec23e479a8218b52c35f7c39bb.pdf