© Copyright: Images: Jari Peltomäki, Jouko Lehmuskallio, M. & W. von Wright: Svenska fåglar (Kansalliskirjasto, The National Library of Finland), M. & W. von Wright (Kansalliskirjasto, The National Library of Finland). Recording: Jan-Erik Bruun. All rights reserved.
- Name also: Northen House-martin
- Family: Swallows – Hirundinidae
- Appearance: A broad-shouldered swallow with pure white underparts and dark upper parts with a distinctive white rump patch.
- Size: Length 13.5–15 cm, weight 12–22g.
- Nest: Under the eaves of buildings or cliff edges. Round with a narrow entrance hole, walled with clay. Lined on the outside with straw and root fibres, and on the inside with feathers, pieces of thread etc.
- Breeding: 2–7 eggs laid in May–June, incubated by both parents for 13–19 days. Young birds learn to fly within 24–28 days, but return to the nest to roost with their parents until their first autumn migration.
- Occurrence: Breeds in small colonies in human settlements throughout Finland. Finnish breeding population estimated at 30,000–130,000 pairs. Numbers have declined in recent times.
- Migration: By day, leaving Finland August–October, returning April–May. Winters in tropical Africa.
- Diet: Flying insects.
- Calls: A dry “prit, pritt-pritt”.
- Endangerment: Endangered, protected in Finland. Globally Least concern.
House Martins have pure white underparts and metallic bluish black upper parts, except for a large white rump patch which is a conspicuous distinguishing feature even at a distance. Their tails are forked, but not as deeply as those of Swallows. House Martins’ legs are covered with feathers, uniquely among Finland’s breeding passerine species. Their beaks are black and their irises are dark brown.