In August, Cuckoos and Swifts start their return journeys to their African wintering grounds, while others, like Chiffchaff, will be building up their fat reserves in time for their departure by gorging on autumn fruits. Our gardens may also be quieter because many of the usual visitors will also be gorging on berries in woodlands and hedgerows.
Some species migrate to their wintering grounds in one non-stop flight and others do it in several short stages. Before departing they gorge themselves on berries to build up their fat reserves, which can then be converted to energy for flight. Their body weight may increase by up to 50%.
The Wildlife & Countryside Act allows you to clean out your nest boxes between 1st August and 31st January. However, some birds may be having late broods and so it is better to leave things for at least another month or so.