Common House Martin - Distribution and Habitat

Distribution and Habitat

The subspecies D. u. urbicum breeds across temperate Eurasia east to central Mongolia and the Yenisei River, and in Morocco, Tunisia and northern Algeria, and migrates on a broad front to winter in sub-Saharan Africa. D. u. lagopodum breeds eastwards of the Yenisei to Kolyma and south to northern Mongolia and northern China; it winters in southern China and Southeast Asia.

The preferred habitat of the Common House Martin is open country with low vegetation, such as pasture, meadows and farmland, and preferably near water, although it is also found in mountains up to at least 2,200 metres (7,200 ft) altitude. It is much more urban than the Barn Swallow, and will nest even in city centres if the air is clean enough. It is more likely to be found near trees than other Eurasian swallows, since they provide insect food and also roosting sites. This species does not normally use the reed-bed roosts favoured by migrating Barn Swallows.

It uses similar open habitats on the wintering grounds, but the Common House Martin is less conspicuous than wintering Barn Swallows, tending to fly higher and be more nomadic. In the tropical parts of its wintering range, like East Africa and Thailand, it appears to be mainly found in the higher areas.

The Common House Martin is a migrant which moves on a broad-front (i.e. European birds are not funnelled through the short sea crossings used by large soaring birds, but cross the Mediterranean and Sahara). While migrating they feed in the air on insects, and they generally travel in daylight, although some birds may move at night. Migration brings its own hazards; in 1974, several hundred thousand birds of this species were found dead or dying in the Swiss Alps and surrounding areas, caught by heavy snowfall and low temperatures. Adult survival on autumn migration depends mainly on temperature, with precipitation another major factor, but for juveniles low temperatures during the breeding season are more critical. It is anticipated that since extreme weather is predicted to become more frequent with climate change, future survival rates will depend more on adverse weather conditions than at present.

The Common House Martin returns to the breeding grounds a few days after the first Barn Swallows; like that species, particularly when the weather is poor, it seldom goes straight to the nesting sites, but hunts for food over large fresh water bodies. There are records of migrant House Martins staying to breed in Namibia and South Africa instead of returning north. As would be expected for a long distance migrant, it has occurred as a vagrant eastwards to Alaska and west to Newfoundland, Bermuda and the Azores.