Page 62 - BBC Wildlife Volume 36 #06

are the most aerial and mysterious of birds, Long suspected, this phenomenal feat fascias, swifts are left homeless. ‘Eco-friendly’
mercurial creatures with an uncanny habit of was proven only in the last few years, when architecture, which creates ultra-insulated
materialising out of thin air. Swedish researchers fitted common swifts spaces, doesn’t help. Smooth facades in urban
Our species – there is only one in the with tiny 0.65g geolocators. Accelerometers centres, often of glass, are even worse.
British Isles – is the common swift. Never still, on the tags recorded movement every few “I could tell there were fewer and fewer
it cruises at 65kph and accelerates to 112kph seconds, though the swifts had to be re- swifts and had to do something,” Rowena
with a few power strokes from a crossbow-like caught in Europe the following year to access says. Her anecdotal evidence from Wiltshire is
48cm wingspan. Some species – the Asian information stored on the devices. Even more backed up by national data. According to the
needletails – are even speedier. Swifts are the accurate GPS loggers have shown that the Breeding Bird Survey (BBS), swift numbers
fastest recorded birds in level flight. Famously, birds travel at least 70km on foraging trips. crashed by 53 per cent between 1995 and
they feed, drink, sleep and – sometimes – 2016. This figure masks more severe regional
mate on the wing (pairs also mate at nests). A SWIFT DECLINE falls – swifts declined by 66 per cent in north-
Might they preen in midair too? It’s a lifestyle The amazing ecology of swifts partly explains east England, for example. Loss of nest sites
that Simon Barnes, in How to be Wild, sums why there is a growing ‘swift community’ is likely the main cause; since swifts trawl the
up as: “Volo ergo sum, I fly, therefore I am.” devoted to them. Just as significant is their wide blue yonder for invertebrate plankton,
Swifts rarely touch any hard surface from plight: no British birds are more dependent they are probably less affected by habitat loss
fledging until, some two or three years on humans. Apart from a handful of swifts than Africa’s other migratory birds.
later, they first explore a potential nest site – nesting in quarries in Northern Ireland, some As is often the case, the Bradford-on-
behaviour nicknamed ‘banging’ for the way in holes in Scottish pines and a few using Avon swift group emerged organically, as an
they wing-bump the entrance. As adults, they cliffs on Norfolk’s coast at Hunstanton, the offshoot from an existing community body
land to incubate eggs and raise young, but entire population relies on buildings. focused on climate change. “Things took off
between each three-month breeding season Whenever we renovate our homes and in 2013, when we tried to organise a survey of
will fly nine months non-stop, much of that offices, repointing crevices and replacing the town’s swifts,” explains Rowena. “It was
over rainforest from Congo to Mozambique. draughty eaves with tight-fitting soffits and difficult, because you’re attempting to count

SAVING SWIFTS
THE RINGER SWIFTS ARE

Simon Evans, Bury St Edmunds, Su olk SUCH MERCURIAL
CREATURES, WITH AN
I’m jointly in charge of Ringing tells us about
Thetford Forest ringing breeding success and UNCANNY HABIT OF
group. Being a firefighter, longevity. In 2017, we had
I have a head for heights, our first recapture – of a MATERIALISING OUT
so am happy shinnying swift we ringed as a chick
up ladders to reach swift in 2015.Judith and I would OF THIN AIR.
nests. I also ring the swifts love to find one of her
rehabilitated by Judith rehabilitated birds to prove
Wakelam. Swifts and that it migrated back safely.
kingfishers are the UK’s People doing similar work
only birds to take a special in Barcelona have had a few
ring designed to fit their ‘returns’, so it does work.
very short tarsus (the
exposed part of the
leg).You have to take
great care fitting it,
ensuring the toes are
out of the way. In swiftts,
the hind toe has partlyy
rotated around the fooot
so efectively you havee
four front toes.
Usually I ring just
nestlings – parents
at the nest are easily
disturbed. If an adult
happens to be in a Simon expertly
nestbox and has a rings a swift
nestling in
ring, I quickly pick it
the tower of a
up to read the unique Sufolk church.
number, but never
prolong the handling.
62 BBC Wildlife June 2018