The humble house martin The House Martin (Delichon urbicum) is one of three Hirundine species that breed in the UK (alongside Swallows and Sand Martins). As the name suggests they readily use manmade structures for breeding. And can be identified by their dark backs, pale bellis and white rumps with a short forked tail. This smart little bird arrives in the UK form sub-Saharan Africa in late March and April. They quickly get on with the business of breeding making their distinctive cup shaped nests which are built colonially on buildings with overhangs. Originally House Martins would have built their nests on cliffs and in caves. However, in today’s modern world they have switched to sharing their homes with us. Despite this change the still built their nests from muds which is gather from pools and puddles near the nest site. Once the nest is built each pair will usually raise two broods each containing four or five chicks. They are insectivores and feed on the wing. Each pair needs to catch thousands of insects to raise a brood. Once juveniles have fledged they will form large feeding flocks with the adults before leaving our shores for Arica from July until October. If you want to encourage House Martins to nest they will readily to artificial nest boxes. Birds will typically live 2 – 3 years, but the oldest individual recorded was over 7 years old and must have clocked up some serious air miles. Sadly in recent decades, the number of House Martins has declined and as a result in 2021 they were added to the UK red list. Causes of their decline may include: lack of nests sites, poor weather, reduction insect abundance and a lack of mud for nest building. The decline of House Martins and their dependence on buildings makes them vulnerable to developments and changes in the way buildings are constructed. This means your records of breeding House Martins are even more important.