By Olivia Apletree |
Aug 10, 2022 |
posted in Latest news|
Our resident Lesley at Sutton Bridge has been dedicated to helping swifts for over 6 years. Her extensive fundraising, has seen 6 swift nesting boxes in St.Matthew’s church. Not only did she raise enough money to install the boxes, there is a live webcam feed where anyone can view these amazing birds at any time! www.naturewatchcam.co.uk
It would seem all the hard work has paid off as there is a new chick in nest box 1!
Lesley has supplied us with some amazing facts about swifts and their conservation.
Swifts are only ‘British birds’ for a quarter of their lives (three months per year) – the rest of the time they’re African
They have soft beaks – but very powerful feet
Their four toes are arranged in twos, each pair pointing sideways rather than forwards, a bit like a chameleon or a koala.
The wings are long and narrow, and superbly adapted for fast flight, but don’t allow slow flight or a great deal of manoeuvrability
In flight the forked tail is closed to a point for extra efficiency
A swift weighs about the same as a Cadbury’s Crème Egg
For its size, the swift has an exceptionally long life-span – averaging about 5.5 years.
Eyes are deep seated and have moveable bristles in front – sunglasses for reducing glare.
All birds have fleas and feather lice or similar parasites. However the swift’s are so different to those of other species that it supports the fact that they separated from other bird species a very long time ago. Their parasites have evolved with them.
Swifts were once thought to hibernate over winter – like swallows, which were believed to hibernate in mud below ponds. Even the naturalist Gilbert White in mid 18C got labourers to dig up likely spots to see if he could find any. He heard tales of swifts being found alive but torpid in church towers in early spring.
Edward Jenner, he who invented vaccination, marked several swifts by cutting off toes and noticed that they appeared in the same place the next spring. He was convinced that they’d migrated – and in evidence noticed that the re-appearing birds were fat and in excellent condition
They almost never land – except at their nest sites – doing everything on the wing
A healthy adult swift can get off the ground but rarely needs to. Starving young ones usually can’t and these are the ones most often seen.
They can sleep on the wing, in mid-air!
Not many predators can catch a swift – hobbies may take a few, and so may kestrels, tawny owls and barn owls.
They seem to bathe by flying relatively slowly through falling rain.
The swift probably eats more species of animals (small insects and spiders) than any other British bird. David Lack recorded over 312, and reckoned there were more. They usually take items 2-10mm long.
They probably hunt at about 25 miles an hour
They drink by gliding over smooth water and taking sips
Swifts can be quite selective about what they catch. One was found to have caught only stingless drones around bee hives, and to have neatly dodged all the females, which had stings
Swifts can’t feed in wet weather in the UK, so fly around storms to find dry areas – the only UK birds to do this.
On the wintering grounds in Africa it’s different – there are more insects in the air on rainy days, so the swifts will head for rain.
It seems they really can mate on the wing – but they will also mate in their nest holes. No other bird is known to mate on the wing (apart from some other swift species)
Use saliva for nest building – like the edible nest swifts
Nesting material is collected on the wing (it has to be) so they can only use what they can find in the air – David Lack once recorded them using a live butterfly!
The weight of an egg is about one-twelfth the weight of the female that laid it approx 3.5 grams
They have a clever adaptation. Food can be scarce in bad weather – the chicks can go cold and torpid and survive for days without food, then regain weight rapidly once supplies resume. Most baby birds can’t do this and would simply die within hours.
Only one other kind of bird can lose temperature control and become torpid each night – the hummingbird. This saves energy.
The length of time the babies spend in the nest will vary, depending on how good the food supply has been, and can vary by up to three weeks – this is different to birds like robins and blackbirds which leave when they are a certain age, no matter how well they’ve grown.
Each bolus (ball of food) brought to the babies weighs just over a gram, and contains 300 – 1000 individual insects and spiders. The average is 300-500 food items per bolus
At about a month old, the babies do ‘press ups’ in the nest, lifting themselves up by pushing down on their wings. By the time they’re ready to go, they can hold their bodies clear of the ground like this for several seconds
Once they launch themselves off on their very first ever flight, that’s it, they don’t return to the nest and are no longer cared for by the parents.
Unlike many birds, the siblings do not necessarily leave together – each goes in its own time, when it’s ready.
How can we protect this endangered species?
Leave existing nest sites undisturbed
When repairing buildings, make sure new access holes match the old location
If you can’t make internal spaces, put up nest boxes
Get in contact with conservation organisations if you see any nest sites.