• ​Swifts have a wingspan of up to 48cm and a body length of up to 17cm. They weigh 36-50g. 

 

• Swifts can reach speeds up to 69 miles an hour in flight and although a Peregrine can beat that in a diving flight, the Swift is the record breaker in level flight.

 

• Once known as the "Devil's bird" for their piercing call that was said to be the tormented souls of the dead going to hell. It was also thought that they hibernate in mud and that they had no legs (their scientific name Apus apus translates as “without foot”). They do have legs but they are short.

 

• The Common Swift breeds across Europe as far north as Scandinavia, across into Asia to China and as far south as parts of India. However they all return to sub-Saharan Africa after breeding.

 

• Common Swifts probably originally nested in caves and cliffs but now depend almost exclusively on human structures explouting small crevices, eaves of older houses and gaps in roofs. In the UK a few tree nesting colonies are still found in the ancient Caledonian Pine Forests of Scotland.

 

• There are an estimated 59 thousand breeding pairs in the UK with the highest numbers in the south and east. However their numbers have crashed. For every 10 birds in 1995 there were only 3 in 2024 and the species is now on the UK Red List of conservation concern. One of the main reasons for the decline is thought to be the loss of suitable nest sites due to home improvements and new building methods not leaving the spaces that would once have been available such as gaps under eaves and roof tiles. Scotland became the first country in Europe to make 'Swift bricks' compulsory in new builds but despite several high profile campaigns this hasn't been adopted by our Parliament.

 

• Swifts live off flying insects and spiders collecting all their food in the air. In fact they spend their lives on the wing, feeding, sleeping and even mating in flight. It's remarkable to think that the only time the birds over us might touch ground is when they land in their nest site here in the village. It had been suggested that Swifts might roost on their wintering grounds but recent research has confirmed that breeding adults can spend 10 months on the wing. Even on migration they will only land if they are forced to by adverse conditions. 

 

• Adult Swifts catch prey on the wing, storing them in a throat pouch and binding them with saliva into a "bolus" (ball of food) to feed their chicks or consume while flying. A parent Swift needs to catch up to 20,000 insects a day, carrying up to 1,000 insects back to the nest in a single bolus. Remarkably they catch each insect individually in mid-air rather than simply flying with their beaks open.

 

• To sleep Swifts ascend to high altitudes and then they can glide with half their brain resting while the other half stays alert (a state known as unihemispheric slow-wave sleep).

 

• According to the BTO birds may live up to 9 years but one ringed individual was found to be 17 years and 11 months old.

 

• Swifts usually reach breeding age at 4 years. They often pair for life and return to the same nest each year. Research found that 9 out of 10 reused their nest site and only 5% of pairs 'divorced'.

 

• Swifts like to nest colonially. Young birds looking to find a suitable nest site may fly close to a potential site such as a nest box repeatedly flying past and hitting it with a wing to check if its occupied earning them the name 'Bangers'.

 

• Swifts legs are adapted to cling to vertical surfaces rather than perching. As a Swift approaches the entrance to its nest they perform a dramatic upward swoop just before the entrance to air-brake and enter seamlessly without having to stop. This trajectory requires a completely clear vertical drop of at least 5 meters directly below and in front of the entrance.

 

• The recommended size for the hole in a Swift nest box is just 28mm high by 65mm. Given that the Swift has a wingspan of up to 48cm that makes their ability to enter without stopping even more amazing.

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• Normally they have only a single brood each year consisting of 2-3 eggs. Incubation takes place for 19-24 days with both parents sharing duties. The hatched young normally fledge between 35-56 days but this is highly dependent on food availability. After fledging the young Swifts will fly off to live entirely in the air without any further parental guidance.

 

• Catching their prey in the air they are dependant on the weather. Adult Swifts may have to make long flights to catch food for their young but, by going into a semi-torpor, the young can survive in the nest for up to 48 hours without a feed.

 

• Listen on a summer evening as groups of Swifts with their young scythe through the air but don’t delay as they leave us all too soon. Usually arriving early in May they leave in early August and, of our migrant birds, only the Cuckoo (which leaves it's parental duties to other birds) spends a shorter time with us.

 

• Their annual migration journey is estimated to be 3,400 miles each way and given that the typical life is estimated as 9 years (source: BTO) that's a lot of Air-miles! One study found they can fly 350-500 miles per day on migration. It has been calculated that a Swift might fly 4 million miles during their lifetime - the equivalent of flying to the Moon and back 8 times!

 

• Due to their aerial feeding flights, Swifts may be mistaken for the hirundines (Swallows and Martins) but they are not related and their stiff winged flight is totally different when you get your eye in. In fact the Swift's closest genetic relations are the Hummingbirds.

 

• There are around 100 species in the Swift family but the Common Swift is the only member of the family to breed here. However other members of the family can turn up as irregular overshoots notably the Alpine Swift, Pallid Swift, Little Swift and even the Pacific Swift (which breeds in Eastern Asia) can turn up.

 

• Swifts need our help urgently. If you'd like to know how you can help them, perhaps by putting up a nest box, take a look at the Swift Conservation website https://www.swift-conservation.org/

 

• To see where Swifts have been nesting and to log records of screaming parties, nest boxes and nesting Swifts, go to Swift Mapper https://www.swiftmapper.org.uk/