Spring heralds the arrival of the charismatic house martin, returning from its wintering grounds in Africa, to its northern breeding grounds, which includes the UK and Ireland.
At House Martin Conservation UK & Ireland, a newly formed charity run by enthusiastic volunteers, we look forward to an exciting spring and summer as house martins flit across our skies.
These beautiful birds with their fluffy white legs, white underparts and rump, black forked tail and upperparts, and a shimmering glossy blue on their head and back, have the power to charm.
House martins usually breed in colonies, building their nests out of mud pellets which they collect in their beaks. Around 1,000 mud pellets mixed with grass are used to build a nest which can take two weeks to complete, and once constructed house martins will continue to make mud repairs to the nest year after year.
When and where to look for house martins
In the UK, most nests are built under the eaves of buildings, however there are still some colonies that nest on cliffs; their natural nesting site before our civilisation constructed buildings.
Being social birds, their “pritt pritt” calls, and vocal chit-chattery, are a pleasing sound to the ear, and invoke our senses to warm sunny days in spring and summer.
House martins stay with us in the UK from April until September, and even into October in a good year, usually raising two broods of four to five eggs, but sometimes three if the season goes well. Young from the first brood have been observed helping to raise the second brood, which is unusual, and shows how socially minded these birds really are.
Their diet is insects, collected on the wing, typically at higher altitudes than other hirundines such as swallows, and other martin species, which is believed to be why their legs are covered in tiny feathers; to protect them from the cooler air.
You may have fond memories of thriving house martin colonies in local communities from decades past, and you might be lucky enough, present day, to have them nesting on your house, or nearby. Watching the birds build their nests, listening to the chattering calls of adults and young, and marvelling at their agile flight in their pursuit of insects are all delights of sharing life with house martins.
Changing fortunes
Unfortunately, like much other wildlife, house martins are in decline, and people from younger generations may never have seen a house martin nest proudly adorning buildings, or even seen a house martin!
Having declined in the UK by 57% between 1969 and 2018, the once thriving house martin colonies have dwindled, and are completely lost in many locations. The bulk of declines have been found in England over the last 10-15 years; populations in Scotland and Northern Ireland appear to be faring better over the same period. It is due to this decline that in 2021 the house martin was reclassified as Red listed in the Birds of Conservation Concern report, putting it in the top division of birds we should be concerned about.
There could be several reasons contributing to their decline:
Weather systems can affect the availability of mud and invertebrates, and long hot summers can cause nests to collapse, sometimes with eggs or chicks inside. Severe weather events may affect migration to and from their breeding grounds, delaying breeding and reducing the number of broods laid, and harsh, extreme wind and rain can cause fatalities.
A worsening or loss of habitat can diminish food and water availability, which in turn can lower survival rates of adults and young. This can affect both their breeding grounds, and their migration routes when they need to refuel often over their epic journey of thousands of miles.
Suitable nest sites are in decline due to renovations and new buildings using unsuitable materials, such as plastic soffits, which a house martin cannot stick mud to, or shallow eaves where nests will be too exposed.
The great news though is that we can take action to help house martins and try to reverse their decline.
How can I help?
There are several ways in which we can play our part to aid these wonderful birds:
Look out for house martins returning to your communities, identify nesting sites, and record your sightings on systems such as BirdTrack.
If you own your home, install artificial nest cups, which are readily adopted by house martins if they are situated in the right place and with a supply of mud nearby (which you could also introduce via a pond). If you are in an area where house martins are not currently present, using a call system can help house martins find your nests.
Ponds are a great way to attract insects, and planting native trees, shrubs, and flowers, will also increase the number of insects visiting your garden or community, which in turn will help provide food during the breeding season.
If you have house martins nesting with you but need to do renovation work that would disrupt the nest, only do this outside of the breeding season (it is illegal to remove or disturb an active nest of any bird in the UK). Between November and February is safest, but always check that the birds have left, or have not returned before commencing work. Replace the nest with an artificial nest cup so that when house martins return the following year, they have a nest to return to.
If you know where a colony’s local mud patch is, keep it wet if it starts to dry up in long dry spells of weather.
Talk to people in your neighbourhood and community, share information about the plight of house martins, and actions that can be taken to save them: there are resources to help on the House Martin Conservation UK & Ireland website (www.housemartinconservation.com)
When you hear about new housing plans, ask developers to feature house martin nest cups in their design as part of their planning proposals.
Some people do not tolerate house martins because they leave droppings, this can be easily remedied by installing a dropping board at least two metres below the nest to collect them. Alternatively, situating flower beds, or flowerpots underneath nest sites is also a good idea, as soil will absorb the droppings and provide nutrients for the plants.
Become a member of our group, and if possible, volunteer some time by becoming a field representative and monitoring local house martin communities.
What’s Happening Locally?
Here in Cookham, we only have two main sites where House Martins breed: Odney Club and the eaves of the nearby Holy Trinity School in School Lane.
WildCookham has arranged the installation of a number of artificial nests on local houses situated between these two locations, in the hope that we will encourage the colony to spread out and fill in the gaps. If this succeeds, we might try to encourage them to other local areas by the same means.
A team led by Barry Weare will be monitoring these nests during the summer in the hope they will get taken up. A successful pair can raise three broods per year if there is sufficient aerial insect life for them to survive on. Let’s hope it proves to be a brilliant summer for these much-travelled jewels of the air.
Mike Copland and Brian Clews
(Photos by Paul Stevens)