House Martins and Swifts

House Martins and Swifts

A summer’s evening and once again Sudbury’s water meadows reveal some of their magic.

While we sit on the riverbank on Kings Marsh, a dozen or so house martins fill the space around us, putting on a breath-taking aerial display – swooping and veering off, returning and haring along inches above the water. We twist our necks to follow their trajectories – back and forth, up and down – and exclaim in wonder as if we are at a firework display.
 While these incredible birds are obviously feeding on the many flying insects found around the common lands at this time of year, it’s clear they are also just having a darn good time, rejoicing in their ability to perform such awe-inspiring acrobatics.

For the past few months, the centre of Sudbury has been inundated by house martins who together with the many swifts have taken up residence in our housetops and streets. On another recent warm evening as I walked through the town, I had no option but to stop and marvel at the sheer number of these airborne wonders. The chit chit of the house martins and the swifts’ iconic screams contributing to the soundtrack of our summer.  We in Sudbury are lucky to have such a visible clutch of these seasonal visitors. The cattle on the meadows stir up a heady mix of insects, aphids and spiders, which float into the air above the town and attract these streamlined fliers who feed on the wing. Swifts, in particular, have evolved to do everything on their scythe-shaped wings, including sleep, mate and drink. One memorable wildlife encounter I can recall is canoeing on the river by Friars Meadow while swifts dive-bombed around me, scooping tiny mouthfuls with each plunge.

But unfortunately, across the country the story for both species is one of decline. According to the RSPB, house martin numbers have halved since 1960 while the UK population of swifts has seen a similar crash in just the last 20 years. The situation is so dire that an annual Swift Awareness Week is held every July to raise the profile of this dangerous trend and to muster efforts to arrest it.

While the house martin, together with its close cousin the swallow, and the swift are all held dear in British culture, these birds spend less than four months on our shores. The majority of their lives is played out on the African continent from where they migrate each year to Blighty to breed. These birds are so cherished here, therefore, because their much-anticipated arrival marks the start of the summer while their departure signifies the beginning of the end of the short-lived good weather, a fleeting taste of the exotic

Because of this lifecycle, the reasons behind the decline in house martin and swift numbers are complex. Changes to climatic conditions and more extreme weathers events in Africa and on migration routes are partly responsible. The continued use of pesticides everywhere, which has reduced the number of insects they feed on, is another cause. Over here, a reduction in suitable habitats for nesting has also hit both species.
As their name would suggest, house martins build mud nests in the eaves of roofs while traditionally swifts have bred in the gaps in rooftops of barns and old houses. But in the age of the barn conversion and modern housing, many of these locations are no longer available.

That is why people put up swift boxes. Former Sudbury Common Lands Charity ranger, Adrian Walters, paid for a number to go into St Peter’s church while three more can be found on the front of the Christopher Centre on Gainsborough Street. I’ve put two up on the back of my house this year.  Every house should have one – you can make or buy one. Find out more from the website and get involved and help give these weary travellers the welcome they deserve when they (hopefully) return next summer.  

Ross Bentley, Trustee of the Sudbury Common Lands Charity