House Martins, like Swallows, are African visitors
Like the Swallow, the House Martin is a very common and very widespread summer visitor to Ireland from tropical Africa.
While many people confuse the two species, the pair have several clear distinguishing features: the House Martin has a large white rump patch, a short, forked tail like a fish and a black and white face whereas the Swallow has a dark rump, often long tail streamers and a red face.
Furthermore, the Swallow usually builds indoors in a barn, shed or other building whereas the 'house' part of the House Martins' name bears testimony to the birds' preference for building out of doors high up under the eaves of houses.
The Martin is one of the few birds called after a popular first name for men and boys. Some claim the name is derived from the birds' habit of migrating on Martinmas, the feast of St Martin of Tours celebrated on 11 November. That may be so in other parts of its range that extends from the Mediterranean to the far north, but in Ireland most of our birds are usually well gone by the end of September several weeks before Martinmas.
Some house-proud property owners don't welcome nesting House Martins due to the mess they can make when their droppings accumulate on a house wall and path under the nest. Worse still if the nests are above a door or window.
Birds will often reuse the nest they built the previous year so over the winter one can prepare for their return by securing a length of board about 250mm wide to the wall below the nest site using L-shaped shelf brackets screwed to the wall above the board. The board and brackets can be decorated to match the colour of the wall.
A pair of House Martins usually remain together for a breeding season but usually split up when the season finishes. Both parents work together to build the nest. They need to be near a source of suitable damp mud. They fashion beak-sized pellets of the wet mud and stick these both to the wall and to each other to form a rounded half-cup. Plant fibres are used to bind neighbouring pellets to each other and to strengthen the structure.
It takes a couple of House Martins about ten days to complete a nest. For late starters, nest building was a particular challenge this summer due to the prolonged dry spell in late May and early June.