Why Do Swallows Love Puddles?

Posted by on May 24, 2022 in Unmowed Blog | 0 comments

barn swallow mud nest building

photo by lloyd holmes

Swallows are the X-wing fighters of the bird world. In their quest for insect food (largely mosquitoes, thank you very much!) they swoop and soar and loop-the-loop like so many pilots dive-bombing the Death Star. They seem to live in the air, these stream-lined birds, with their curved, pointed wings so superbly adapted for flight. I don’t think I’ve ever seen one perched in a tree.

But like all terrestrial beings, they have to come to earth sometimes. And when they do, these aerial acrobats get down in the mud.

Barn swallows need mud to build their homes. They scoop up beakfuls of mud from the edge of a puddle or streambank and then use the damp mud as plaster to build a strong nest that endures like pottery. Shaping it one meticulous mouthful of mud at a time, they use grass to strengthen the structure. It might take upwards of a thousand separate trips to the mud source before the nest is completed to the swallows’ satisfaction. Male and female work together, and they build to last. In my old barn there are barn swallow nests protected from the rain that are decades old.

Puddles are a crucial source of home-building materials for dozens of species of birds. Barn swallows, cliff swallows, robins, and phoebes are just a few of the birds that depend on mud to raise their young.

But mud puddles are getting harder to find these days, as driveways, country lanes, and farmyards are blacktopped and lawns are manicured. If there’s no mud, there’ll be fewer baby birds. Lack of a readily available source of mud for nest building is directly linked to declines in populations of barn swallows.


To find out more about puddles and the amazing variety of wildlife that depend on this odd, ignored habitat, please check out my picture book: Hello, Puddle!


For an amazing video of swallows in action check out this video made by Mark of Avibirds Project

barn swallow mud build nest

photo by lloyd holmes

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