By Graham Fulton – PhD student, School of Biological Sciences, The University of Queensland
I would like to find out something about swallows: we have noticed that they return to the same nests each year, but there must be younger birds that have no nest. Where do they sleep until they have built their new nest? – Nefeli, age 13, Corfu, Greece.
Thank you for your question, Nefeli.
It’s true that some swallows return to the same nests each year. But what do they do there?
We need to understand what nests are really for – and they are not for sleeping. They are for putting eggs into. The eggs need protection from the weather (hot and cold, wind and rain) and from other animals that would eat them. For predators, eggs taste great!
Eventually the eggs hatch, then a blind and featherless baby swallow emerges. The babies are called nestlings or sometimes chicks. So nests are not for sleeping, they are for raising a family.
It is true that when an adult is sitting on eggs and nestlings, it may sleep, especially at night.
But the young swallows who don’t have a nest to return to must build their own nest (to protect and feed their babies) or sleep on a tree branch, a rock ledge of a cliff face, or inside the hollow of a tree.
When swallows sleep away from the nest they sleep in places called roosts.
So remember: nests are mostly for babies; roosts are for sleep.
This article was originally published on The Conversation.