Flying, the swallow is most graceful. Its effortless twisting and
turning in
 search
of food is a delight to watch. The ceaseless flight is occasionally
interrupted by a brief stall to intercept an insect which has nearly —
but not quite — passed. The long tail is used to good effect to
accomplish the intricate manoeuvre.
The swallow's close relation, the house martin, usually feeds at a
considerably greater height than the swallow, as does the swift. In fact
only during cool, wet or windy conditions will all the hirundines and
the swift be found feeding together low over a broad or in the lee of
woodland from which insects may be blown or where food may be
sheltering.
Eggs are laid one a day and there is often a second clutch. In cold
weather feeding the young becomes difficult. At such times the male
swallows act rather selfishly. The females spend as much time feeding
their brood as they do looking after themselves.
But the males put much more effort into seeing to their own needs.
Both male and female are aggressive at the nest, chasing off intruders;
threatening with feathers raised and bill open — even fighting fiercely.
Swallow in flightParent swallows feed a wide variety of insects to
their nestlings — including wasps. Flies are certainly favourites,
particularly for first broods. Eight out of every 10 insects eaten are
flies. Surprisingly, most are large including greenbottles, bluebottles
and horseflies.
For the first few days after the nestlings have hatched, unmated male
swallows are frequent visitors to the nest. Surprisingly, one way that
such males can acquire a mate is to kill the young nestlings and then
pair with the female who has to start a new family. One observer watched
a male remove a whole brood by picking up each nestling, flying some
distance away and then dropping it on the ground.
After breeding swallows gather in communal roosts, sometimes
thousands strong. Reedbeds are regularly favoured. The birds give
spectacular pre-roosting displays, bunching tougher and towering higher
and even higher before swerving and swirling en masse before swooping
low over the reeds.
Swallows are able to obtain food while migrating. Unlike most other
passerines they are diurnal migrants, travelling at almost ground level
and skimming the waves whereas most migrants move at a height of several
thousand feet. To drink, these graceful birds skim low over the surface
scooping water with open mouths.
Swallows usually nest close to man. On occasions pairs occupy the
same building with nests as close as a yard apart. In dry conditions
when wet mud is difficult to obtain swallows will take over old nests of
other birds including house martins and blackbirds.
Swallows do not often settle on the ground except when collecting mud
for nest-building. Then they appear nervous, using a shuffling walk as
they gather at muddy dyke edges where cattle come to drink.
Swallows rarely settle in large trees, except on bare long dead
branches. However, they frequently use willow plantations and reedbeds
for the impressively large roosts formed prior to departure. At times up
to 4000 swallows may assemble.
Each morning, favoured lengths of wires are lined with hundreds of
adult and young swallows. Then one day the cables are deserted. Th e
6000 mile journey to South Africa has begun. Towards the end of this
month the majority will have left although in some years sizeable
numbers linger through October. Stragglers are reported until the onset
of night frosts during November and December.
Reaching the Continent our swallows change direction to a southerly
point, the un-ending stream eventually concentrating along the east
coast of Spain. Many cross the Mediterranean heading towards Africa at
the narrowest point in the vicinity of Gibraltar.
High above the skies will be filled with gliding cranes, storks and
birds of prey. Ahead lies the Sahara — a long haul of several hundred
miles which can last for two days or more with little opportunity for
rest, water or food |
