When Do the Swallows Come Back? A Guide to Their Return and Migration

Swallows return to our regions from the middle of April onward, once night temperatures stay steadily above freezing, with the mass arrival coming in early May. The swallow family includes about 120 species that inhabit every continent except the cold polar landmasses. Swallows are regarded as extremely useful birds because, while feeding, they destroy vast numbers of harmful insects.

When do swallows return to our regions?

Swallows arrive over a long, drawn-out period that depends directly on the spring temperatures. You will not see a swallow before April. Only when the temperature stays reliably above zero — most often from the middle of April — can you expect the first of our swallows to appear.

How weather influences the swallows' arrival

Weather governs the timing of the swallows' arrival because their food supply depends on it. Swallows wait for warmth to set in and for insects to appear in the air. In cold weather there are no insects aloft, and the birds would face starvation. This is why the birds seem to hold back their return until conditions are right.

Before rain the atmospheric pressure drops and insects fly lower over the ground; their tiny wings grow damp, which keeps them from rising higher. Following their prey, the swallows also drop low. People noticed this connection long ago, and it entered the folk signs for predicting the weather.

Mass arrival and lone barn swallows

The first swallows to appear in spring are single barn swallows, while the mass arrival happens later, at the start of May. Year after year swallows return to their old nests, and the timing of that homecoming is one of the most dependable markers of true spring. This same faithful return to a single site is what made the swallow a symbol far beyond Europe.

What types of swallows are there?

Three swallows are common in our regions: the barn swallow, the house martin, and the sand martin. They differ in appearance, in the shape of their nests, and in the order of their arrival — barn swallows come first, house martins slightly later, and sand martins after the barn swallows.

Barn swallows

Barn swallows are the earliest of the swallows to reach their nests, which they build under the roofs of human-made structures — in covered yards, sheds, attics, and even entryway passages. Village dwellers are fond of this cheerful, trusting little bird that lives beside them under their special protection.

Appearance of the barn swallow

The barn swallow is most easily told apart by its long narrow wings and its long, forked tail that forms two streamers — the source of its Russian nickname, kosatka. It has a fine, awl-thin black bill, a dark blue glossy back, whitish breast and belly, an orange-brown forehead, a matching orange-brown patch on the throat, and a black band across the chest below it.

Nests of barn swallows

The barn swallow's nest is shaped like an open cup, and this form makes it easy to distinguish from the house martin's nest. It is fascinating to watch two swallows carry moist earth — dampened with saliva — in their bills. Between the lumps of earth they lay blades of grass, feathers, and hairs, which give the structure greater strength, and they mould the nest onto the house right under the ridge. The work is accompanied by constant twittering.

House martins

House martins live in both town and countryside and settle in small colonies. They arrive at their nesting sites a little later than the barn swallows.

Appearance of the house martin

The house martin has a black, raven-coloured crown, back, wings, and tail, which is why it is also called voronok in Russian. The underside of the body is white, and the tail is short with a triangular notch at the end. In flight its white rump is clearly visible, an instant field mark that separates it from the barn swallow.

Nests of house martins

House martins build their nests mainly on stone structures, less often on wooden ones. A martin carries saliva-dampened earth in its bill and, moving its head rapidly, places lump against lump like brick against brick. The freshly moulded parts of the nest are wet and dark, while the earlier-laid parts are dry and light. A pair of martins spends four to five days building a nest.

House martin nests have a distinctive shape. While the barn swallow's nest is open and bowl-shaped, the house martin's is a closed bowl with a side entrance. The nest's shape makes it easy to determine its type. By the end of May, most nests are already built, and they are usually located on the south side.

Sand martins

Sand martins arrive after the barn swallows and live in colonies that are often very large. They differ from the other swallows in the dark brown colour of their back and breast, and their tail is much shorter than that of the barn swallow.

Appearance of the sand martin

The sand martin is the smallest and plainest of the three, with sandy-brown upperparts, a white throat and belly, and a brown band across the chest. Its short, only slightly forked tail and matt earth-brown plumage set it clearly apart from the glossy blue-black barn swallow and the sharply black-and-white house martin.

Nests of sand martins

Sand martins build nests in long burrows along steep banks. The swallows cling to the cliff face with their sharp claws, brace their tails, and poke out the earth with their beaks. Once a small burrow is formed, the birds begin to scrape out the soil with their feet, like a chicken.

Sand martins dig long burrows in steep riverbanks, clinging to the bluff with sharp claws, bracing with the tail, and chiselling out earth with the bill; once a small hollow forms, they rake out the soil with their feet like a hen. Over time the birds abandon their old, well-worn burrows and build fresh ones where the bank is higher, because during a big flood the rising water floods the burrows and washes silt into them, or small animals may creep into the nests and destroy the chicks or eggs.

What do swallows eat?

Swallows feed almost entirely on flying insects — flies, mosquitoes, midges, small beetles, aphids, and winged ants — caught on the wing. A swallow both eats and drinks in flight, snatching insects from the air and scooping up water with its lower bill as it skims a pond's surface. Because their whole diet consists of airborne prey, their arrival, activity, and even flight height are tied to insect abundance.

How swallows benefit people

Swallows benefit people by destroying enormous quantities of harmful insects, which is why village dwellers welcome them under their special protection. A single family of swallows working a farmstead through a summer clears away many thousands of flies, mosquitoes, and crop pests. This natural pest control, together with their trusting habit of nesting on buildings, has long made the swallow a favourite around human homes.

Swallows in folk weather lore

Swallows appear in folk weather signs because their flight height reflects changes in air pressure. When they wheel and skim low over the ground or water, rain is on the way; when they hunt high in the sky, fair weather is expected. The reason is physical: falling pressure before rain forces damp-winged insects to fly low, and the swallows follow their prey downward — a genuine, observable link rather than mere superstition.

How swallows build their nests

Swallows build their nests from small pellets of moist earth mixed with saliva, reinforced with grass, feathers, and hairs, working pellet by pellet like a mason laying bricks. Barn swallows shape an open cup under a roof ridge, house martins form a closed cup with a small side entrance on stone walls, and sand martins dig burrows into riverbanks. A pair of house martins needs four to five days to complete a nest, and by the end of May most nests are finished, usually placed on the warmer southern side.

The flight habits of swallows

The swallow is a superb flier, swift and capable of the most unexpected turns, and this aerial mastery shapes everything it does. Its long, narrow wings let it feed, drink, and even gather nesting material on the wing, catching insects in the air and scooping water with its bill as it passes low over a pond.

Where do swallows fly for the winter?

Swallows migrate to warmer regions for the winter, chiefly to sub-Saharan Africa and southern Asia, because their insect food disappears from the cold northern air in autumn. They gather in large flocks, often lining up on wires, before setting off on journeys of thousands of kilometres. In spring they return with remarkable fidelity to the very same nests, which is what makes their homecoming such a reliable herald of the season.

Breeding and raising the chicks

Swallows breed soon after nest-building is complete, laying a clutch of eggs that both parents help to tend, and they often raise two broods in a single warm season. The young are fed a constant supply of insects caught on the wing and delivered to the nest, and once fledged, the grown young birds build new nests of their own rather than reoccupy the parents' cup. Protecting the nest site matters, especially for sand martins, whose bank burrows can be flooded or raided by small animals that destroy the chicks or eggs.

How to tell the different swallows apart

The three swallows are separated most quickly by tail shape, colour, and nest type:

• Barn swallow — long forked tail with streamers, glossy dark blue back, orange-brown forehead and throat; open cup nest under roof ridges; arrives first.
• House martin — short notched tail, raven-black upperparts with a white rump and white underside; closed cup nest with a side entrance on stone walls; arrives slightly later.
• Sand martin — short, barely forked tail, plain earth-brown back and breast band; burrow nests dug into steep riverbanks; arrives after the barn swallows in large colonies.

Common questions about swallows

The most frequent questions about swallows concern when they arrive, where they go, and how to identify them. Swallows reach our regions from mid-April, with the main wave in early May; they winter in Africa and southern Asia; and they are told apart by tail shape, plumage colour, and nest form. Their low, skimming flight before rain is a genuine weather sign, and they return each year to the same nest sites near human dwellings, where they earn their keep by clearing away harmful insects. Curious readers exploring nature and the natural sciences may also enjoy related topics in the enemies of fish, in agriculture, and in astronomy.