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A welcome distraction from
weeding comes in the form of swifts screaming
overhead. Slowly straightening the bent back, I can
look up and watch a dozen or so slender, black
arrowheads careering around the welkin (a pretentious
and archaic word meaning the region of the clouds).
The swifts are flying in all
directions but they seem to be keeping together as
they ride a thermal. Each one is flying in wide arcs
around a central hub and the rising column of warm air
in the centre of a thermal would explain how the
swifts are managing to glide so far without a wingbeat.
A few swifts are flying much higher but are spiralling
around the same centre. Last week I saw a red kite
riding a similar thermal over the garden, but in a
more sedate, leisurely fashion. (I mention this
because I can claim it as a new species for the
garden, unlike the buzzard that was chased away by the
resident crows just as it was approaching the
boundary.)
The swifts were feeding, no
doubt, on small insects swept up in the thermal but,
once in a while, two or more would close-up and fly
side by side, and I would hear their screams. It was
not so dramatic a spectacle as the screaming parties
that hurtle around buildings in the vicinity of the
colony, but the purpose was the same. Whatever that
may be. This behaviour is not understood but it is
probably some form of 'bonding' by members of a
colony.
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