Experts have explained why gardens in the UK have gone so quiet this month with some people wondering ‘where did all the birds go’ – and there’s a very good reason for it.
It’s all to do with the cycle of life and why birds actually sing – meaning the ‘dawn chorus’ in the spring will always be far louder.
Birdsong dramatically reduces in the UK after late summer because the breeding season ends, adult birds stop singing to defend territory or attract mates, and they are busy teaching their fledglings.
Additionally, birds enter a vital and energy-draining moult to replace damaged feathers for winter. This makes them vulnerable and more likely to hide in cover, resulting in fewer birds being seen and heard in gardens.
Writing on Wildlife Watch Zoologist & Wildlife TV Presenter Yussef Rafik said that there’s an incredible biological reason too – bird brains change during the year.
He said: “Research by some of the world’s top ornithologists has shown that the structure of a bird’s brain actually changes throughout the year. The parts of the brain that are responsible for controlling song get bigger during the breeding season. This helps to give the birds louder and more complex songs so that they are more impressive to any potential mates.”
He explained that once the summer months draw to a close and autumn sets in, the breeding season for most birds comes to an end. He said: “They no longer need to attract a mate, and their chicks have already grown up and left the nest. This means that the adult birds no longer need to keep singing to defend their territory. Many birds will also begin to migrate to warmer countries for the winter.”
One of the primary reasons for the September silence is the annual moult. After the demanding breeding season, adult birds are exhausted. Their feathers, vital for flight and insulation, are worn and tattered.
To prepare for the rigours of autumn and winter, birds undergo a complete feather replacement. This process is incredibly energy-intensive, making birds more vulnerable and less inclined to spend time out in the open.
“Moulting is a physically demanding time for birds,” explains the RSPB (Royal Society for the Protection of Birds). “They need to conserve energy, so they become much quieter and spend more time hidden amongst vegetation, making them less conspicuous.” This period of vulnerability means less singing, less aggressive territorial defence, and less visible foraging.
RSPB tips for feeding birds in autumn and winter
Put out bird food and water on a regular basis through autumn and winter. In severe weather, you may find you need to feed twice daily. Birds need high-energy, high-fat foods during cold weather.
Always adjust the quantity given to the demand, and never allow uneaten foods to build up. Once you have a feeding routine, try not to change it as birds will become used to it.