Over the past few weeks you may have noticed an eerie silence out in the natural world. If you think back to a couple of months ago you may have been annoyingly awoken every morning by blackbirds and robins or you may have enjoyed a nice refreshing drink of an evening listening to the dusk chorus. Either way, at this time of year we have a clear lack of bird song and I am going to explain why!
Birds are moulting. Adult birds shed their worn out feathers and grow strong, warm ones ready for winter. Feathers can get damaged throughout the year from general wear and tear, sunlight and parasites such as lice. A moult is generally spread out over a considerable time to make sure there are no bald patches. Migratory birds are relatively quick at moulting whereas small birds take around 5 weeks.
Moulting can cause a drain on a bird’s resources, it takes a lot of energy to grow new feathers and they will often be less insulated during the moulting process. They will often have to expend more energy when flying as well which is why they tend to stay relatively hidden and inactive. Some birds such as geese, ducks and swans loose all their flight feathers at once which can make them very vulnerable as they are unable to fly. Generally all birds are different and will adapt to the situation that they live in.
With young birds, they will often only do a partial moult. A juvenile robin for instance will lose only his speckled breast and replace it with a nice rosy red one instead. If you are struggling with identifying your garden birds at the moment, don’t worry, at this time of year they can look rather strange!
Laura Preston – Scottish Wildlife Trust, Falls of Clyde Ranger