Keep garden birds well-watered this weekend

Every year migrant birds such as Swallows and House Martins herald the arrival of summer as they complete a 6,000-mile migration from central and southern Africa and start to nest. After Britain experienced its driest winter since 1995, these birds will arrive to conditions that will make building their mud nests much more difficult, which could impact on the chicks surviving.

House Martins and Swallows need wet mud to build their nests, but such materials can be hard to find in hot weather (www.rspb-images.com).

Consequently, the charity is appealing to people to put out a supply of fresh, clean water, as well as some wet mud in a shallow container like a dustbin lid, to help these migrant birds survive the arduous conditions and construct their nests. Leaving out water is also hugely beneficial to other garden favourites such as Starlings, Robins and Blue Tits.

RSPB Wildlife Adviser Claire Thomas said: "Unfortunately the hot weather will make it extremely tricky for lots of birds to build nests and raise their young. Without the right materials to make their nests, such as damp sticky mud, it could lower the chances of their chicks surviving summer. Even a small supply of water can make all the difference."

House Martins often assemble on overhead power lines to rest and feed expectant juveniles (www.rspb-images.com).

Swallows and House Martins immediately start creating or rebuilding nests on arriving back in Britain. House Martins typically use pellets of mud to build dome-shaped nests under the eaves of houses; these can take up to 10 days to finish and depend on a suitable mud supply nearby. It can take a pair of Swallows up to 1,200 journeys to find materials, which are usually located close to large domestic animals such as cattle or horses.

Both bird species can have two or three broods over the summer before leaving the country in September, so a strong nest is extremely important.

Claire added: "As well as ensuring a good supply of mud for nests, people can help many other garden birds by making sure water is always available during this dry spell, for drinking and helping to keep their plumage in good condition."