The RSPB is urging the public to get their hands dirty this weekend and create mud pies to help endangered birds such as house martins, swifts and swallows get enough sludge to build their nests.
A nine-day mini-heatwave is hitting the UK, which coincides with the return of migratory birds here to breed. Many of these birds have flown thousands of miles on their journey. But conservationists are concerned that the ground is getting so hard it could stop them from being able to make their nests.
By leaving out dishes of mud mixed with water, or creating little puddles in the garden, the public can make a big difference, said Becca Smith, of the RSPB. “It’s the easiest thing that people can do to help these birds after they’ve flown all the way from Africa to our shores. Plus, a bit of mud pie-making is fun for the weekend.”
Putting out dishes of fresh water will also provide drinking and bathing for a variety of birds. House martins – which require the most mud for nestbuilding – can mix water with soil themselves, which they then combine with things such as grass, feathers and vegetable fibres to make little cup nests under the eaves of houses.
“Having the mud already created for them is the easiest option for these birds,” said Smith. “It’s a bit like getting a McDonald’s as opposed to having to go out and get all the ingredients yourself and trying to recreate a Big Mac.”
Mud pies should not be too sloppy, but also should not dry out. Smith recommends checking them a couple of times a day to make sure they are still wet enough. She says it’s good to leave birds water and mud every year between March and May, especially if it is dry, because this is a very busy time of year for them.
Some migratory birds have arrived later this year because there have been persistent easterly and north-easterly winds, which make it harder for them to fly northwards. According to Marco Petagna at the Met Office, UK temperatures are “several degrees above where they should be at this time of year”.
In December 2021, swift and house martins joined the UK red list of endangered birds in the latest IUCN update. Swift populations have fallen by 58% since 1995. These migratory birds have suffered from the loss of nesting sites as old buildings are renovated, and also the loss of insects – their food supply. A UK study this week found flying insect numbers have plunged by 60% since 2004.
The RSPB also recommends putting up artificial nests and boxes to provide more nesting opportunities for these birds, as well as creating insect-friendly gardens.
Alexander Lees, senior lecturer in conservation biology at Manchester Metropolitan University, said the RSPB’s recommendations look useful. “More broadly, we need building regulations that mandate spaces for swifts and house martins, and to make sure that any nest boxes are cited appropriately on cooler and shady north or east-facing walls,” he said.
“Given that the loss of insect abundance is likely to be strongly affected by artificial light at night, then we can all make the effort where possible to turn lights off, saving insects, their predators and saving on our energy bills. We need to stop stealing the darkness from the natural world.”