Swallows are the very epitome of summer. In Britain they are distributed throughout the whole country.
In Europe swallows breed northwards as far as the Arctic Circle. During spring successive waves leapfrog northwards over each other. In fact pioneers in southern Europe will have reared first broods to the flying stage before the last migrants pass through to reach the most northerly breeding areas in early June.
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.
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. The 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
By Michael J. Seago