During spring, the birds certainly put on a good show. At first we enjoy the cacophony of bird song surrounding us during the breeding season. Then we can spend time watching busy parents flying back and forth to their hungry chicks from dawn ‘til dusk. Finally, there’s the joy of seeing fluffy little fledglings taking their first flight into the world. By the summer we have got used to regularly seeing birds on our feeders and in hedgerows and then they suddenly disappear!
Have they migrated? Have they all been eaten? Has a disease wiped them all out? No, nothing quite so dramatic has happened. The birds are still around, they’re just hiding whilst they spruce themselves up ready for winter.
Feathers aren’t indestructible. They get damaged, discoloured and weakened during a bird’s busy year. So after a while worn out feathers need to be replaced. This is a natural process called moulting.
August is prime time for bird moulting. Replacing all your feathers is an extremely energy draining experience so birds save it for when they are less stressed – after breeding and before migration. August is also very warm, so the birds don’t get too cold and there is still plenty of protein-rich food about.
The feathers don’t all fall out at once. This would leave birds unable to fly and very, very cold! Instead, each feather is gradually replaced one by one. During the moult, birds have less energy and it’s much harder for them to fly. This makes them very vulnerable to predators, so they spend most of their time hidden in vegetation trying to be as inconspicuous as possible.
Most garden birds take about 6 to 8 weeks to completely moult and then they are out and about again, fattening themselves up for winter.