Tuesday, 18 August 2015

The Devil's Bird

This is an article I wrote to be used elsewhere, but as it wasn’t I have made some changes and additions so that it’s good enough for my blog. :-)  My thanks go to Sam for the added images which are  much appreciated.   The Swifts are leaving now of course, but they will return.

They’ve made it again,
Which means the globe’s still working, the Creation’s
Still waking refreshed, our summer’s
Still all to come –
From Swifts Ted Hughes

Last night I was watching Swifts Apus apus flying in numbers over Killingworth Lake.  I know I’m not alone in welcoming the first sightings of these birds each year as they return to the UK.  The sun was setting behind scatterings of cloud that was edged with varying warm tones of red, as light rain fell on yet another cold spring evening.  Whilst watching these birds not long back from central and southern Africa, neither the cold nor the drizzling rain was in my thoughts.   Samuel and I were preparing to give a presentation for North Tyneside Parks Department so we were both out to gather some inspiration.  The Swifts proved to be a good subject and a species that will definitely be included in a small section of our talk.  Interesting and exciting facts about birds along beside Samuel’s stunning images tend to capture participants attention and that’s how we tend to focus our growing programme of presentations.

Why the title of the Devil's Bird?   Well, it seems that the reasoning behind the name has been lost in the distant past, but until recent years the Swift has been a species little understood, leading to mystique surrounding its lifestyle, so perhaps that indicates some connection to the title.  Birds Britannica by Mark Cocker and Richard Mabey refers to the following vernacular names, ‘devils bitch’, ‘deviling’, ‘devil’, ‘devil bird’, ‘skeer devil’, ‘screacher’,  ‘screemer’, and ‘shriek owl’.  History would suggest that any bird with association to the Devil would be heavily persecuted, but Cocker and Mabey suggest that there is no evidence that the Common Swift has been a target of such practice.  The scientific name Apus Apus stems from Ancient Greek and simply means without feet, and any understanding of the morphology of this bird will immediately give clarity as to why this name came about.

Once a young Swift fledges it is on its own to find food on the wing and its way to its wintering quarters in Africa and it may not land again until it is ready to breed, maybe three years later.    During this time it will eat, sleep and may even mate on the wing.  A French Airman in the 1914-18 war was gliding down in his plane with engines turned off so as to avoid detection when at 10,000 feet he found himself amongst birds which were apparently motionless.  One of these birds was found the following day caught in the engine and found to be a Swift.  My own best sighting of Swifts gaining height in flocks was at Newton Stewart, Scotland some years ago, as I watched other breeding Swifts fly into nesting sites under the eaves of housing.   That legs and feet are not a priority in design of this bird is of little wonder   Swifts mating on the wing was first described by the naturalist Gilbert White (1789).  Edward Jenner (inventor of vaccination) was convinced that Swifts migrated at a time when it was still thought by some that they simply disappeared into mud or pools for the winter.  Jenner marked some Swifts by cutting their toes off (how ethics change!).  He found that they returned to the same place to breed in a fattened and healthy condition and was more than ever certain that his theory of migration was correct.  Moving on many years to 1947 and the renowned ornithologist David Lack began watching Swifts in Oxford and this became one of the longest such projects in the world and which continues to this day.  In 1956 this resulted in the classic book (which I am determined to get a hold of) Swifts in the Tower.  

A common misconception is that Swifts fly with their gapes held open in order to catch prey.  In fact such a tactic would not be sensible in terms of aerodynamics.  Swifts target individual items of prey, thus their twisting and turning in flight.  Swifts also gather all of their nesting material whilst in flight and on one occasion were seen to incorporate a live Large White Butterfly into the nest structure.  During the war Swifts in Denmark and Italy constructed their nests with shreds of tinfoil dropped by the RAF in order to confuse radar.  Incidentally, David Lack worked on radar research for the British Army during the war and the experience gained allowed him to use radar for observations of bird migration

During his study of Swifts Lack found that they probably eat more species of animal than any other British bird having found 400 species in the analysis of just 12 meals.  Meals brought to nestlings contained between 300 - 1,000 insects. A single Swift may deliver 42 meals in a day representing 20,000 insects caught in one day.  Should the weather deteriorate and food be scarce, nestlings have the ability to enter a torpid state during lean times, hence the differences in the length of incubation for individual birds.  One Swift found dying in Oxford was seen to have been ringed as an adult 16 years before, thus making it at least 18 years old.  It was estimated that during its lifetime it may have flown 4 million miles, or put it another way, it may have flown the distance to the moon and back 8 times!  The British Trust for Ornithology study of the Common Swift found that a bird took only five days to fly 5,000kms as it migrated from Western Africa to the UK.  No mean feat for a bird that weighs approximately the same as a Cadbury’s Cream Egg.  The average life of the species is 5.5years.

Numbers of Swifts have declined in the UK in recent years owing probably to many modern building not providing nesting sites.  The BTO point out that a third of British Swifts have been lost since 1995!  According to the new Bird Atlas of Northumbria, Northumberland has not had such a large decline as more southerly parts of the UK, perhaps reflecting less modern building work.  Swifts did of course historically nest in forest areas, but as these disappeared, the birds took to man made buildings.  One of the oldest colonies known to nest in a man made area is the one at the Wailing Wall in Jerusalem.  Be assured that Samuel and I will have mentioned to participants and staff of North Tyneside Parks Department the availability of Swift nest boxes and especially designed Swift bricks which can be added to modern buildings, thus offering nesting sites.  From small seed a mighty trunk may grow.  Conservation is important so we live in hope.

Addendum.  After seeking the inspiration our presentation was cancelled owing to lack of support i.e. nil bookings.  A lack of interest is always such a shame, but time with birds and nature is never wasted and we would have been out there anyway so we gain either way, not least in terms of learning and in experiencing all of the many rewards nature has to offer.


  1. Nice facts and photos. It's a shame about the presentation, but it's their loss!

  2. I have to say that the guy I know at the Parks Department ensured that the talk was well publicised. As the saying goes, 'you can take a horse to water etc etc'.

  3. Yes sometimes folk are just not interested. It's a pity, however, as I'd have hoped that you would have had at least a few people booking up.