How to stop birds nesting in chimneys
Jackdaws and swallows may nest in old cottages with very wide chimneys. Usually modern homes don't have enough chimney space, but here is some advice if you do find birds in your chimney.
Finding birds in your chimney
It is best to prevent this activity from happening.
This is in order to prevent nuisance to yourself, injury to the birds and damage to their nests, as well as reducing the risk of chimney fires. This can be achieved through regular sweeping of chimneys and by fitting a cowl to the chimney pot to prevent access to the chimney.
If there are currently active nests in the chimney, they must be left and fires not lit until they vacate their nests. This is for your safety regarding the risk of chimney fires as well as it being an offence to intentionally take, damage or destroy any active wild bird's nest in the UK under the Wildlife and Countryside Act 1981.
Once inactive get a chimney sweep out and get a cowl fitted either by them or a builder.
If there are birds stuck in your chimney that are not nesting then they can be retreieved by waiting until night time and then making the room at the bottom very dark and shining a very bright torch up the chimney. This entices the birds down to 'daylight' and they can be caught in a sheet at the bottom.
If injured, contact the RSPCA (SSPCA for Scotland, or USPCA for Northern Ireland) or a wildlife rescue which can be found at HelpWildlife.co.uk. If uninjured then release outside. Then follow the instructions above to seal your chimney.
If you have a gas fire you will need to get a qualified gas appliance fitter to come and move your fireplace away from the opening of the chimney to conduct the above work.