The house martin is a small bird with almost metallic, glossy blue-black cap and back and pure white underside with a white throat. It has a distinctive white rump with a forked tail and, on close inspection, white feathers covering its legs and toes. Juveniles have brown crowns and their white rump appears more of a buff grey.
Average Length: 12-15 cm
Average Lifespan: 2-5 Years
Average Wingspan: 26-29cm
The house martin has a flat and wide beak, perfect for catching insects like flies, beetles, and aphids. As house martins eat winged insects they catch whilst in flight, they cannot be attracted to gardens by putting out food in the same way as many other songbirds.
Keeping your garden full of flowering plants and wildlife friendly shrubs is a great way to encourage insect life into your garden and increase your chance of seeing a house martin.
House martins are thought to winter in southern and western Africa south of the Sahara, however, we know very little about their wintering areas. Come April and May, these warm-weather migrants make the journey to the UK to breed. The first individuals to return tend to be older birds, and these quickly occupy those nests that have survived the winter, with other late comers building new nests or repairing ones that are worse for wear!
The availability of damp mud is an important factor when choosing a breeding site. Both males and females collect mud from streams, ponds, and muddy puddles to construct their nests in around 10 days. It is thought that over 1,000 beak-sized pellets of mud and grass are used! Although house martins traditionally built their nests on cliff faces, by the 19th century they had started making use of buildings too. A small number of house martins continue to use natural nest sites, but it may be more common to see their small cup shaped nests under the eaves or ledges of buildings and houses.
These birds are semi-colonial, with an average group size of four to five nests. Some pairs will breed on their own while others breed in large colonies of more than 30 nests. Large colonies with groups of hundreds of nests have been reported! They raise 2-3 broods annually and lay 4-5 non-glossy white eggs at daily intervals. Both sexes incubate the eggs for around 2 weeks, though laying and incubation can take longer if the weather is poor.
The chicks will leave the nest at around 20 days old. Once fledged, the young will use the nest to roost and to be fed by both Mum and Dad for several days. They can remain in the colony for several more weeks before they depart to join pre-migratory flocks.
Possible causes of the decline of house martins include less insect availability during breeding season, restricted nest site availability, limited access to mud for nest building and adverse weather conditions during migration.
Allow a pond in your garden to get a little muddy, to provide the perfect nesting material for house martins to build nests!
Providing specialised nest cups for house martins to nest in.
Plant lots of pollinator friendly plants to attract insects into your garden.
House martins re-use old nests so don’t remove them if you can avoid it!
In Egyptian mythology, swallows, martins or swifts were thought to represent an aspect of the soul, the menet bird. This symbolised freedom, and the pattern shown by such birds emerging at dawn and flying freely, to return at dusk, was theorised to mirror the flight of the human soul.
BirdLife International (2022) Species factsheet: Delichon urbicum. Downloaded from www.birdlife.org on 29/03/2022.
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