Chimney Ducks

I heard quacking while I was making my breakfast and rushed outside with the camera. It was a pair of mallards on top of the northerly boiler house chimney. I know that there are lots of traditions relating to chimneys and chimney sweeps so checked to see if ducks are involved in any of them. In the US wood ducks are often found in chimneys as these birds nest off the ground in crevices. We don't have them in the UK. I was sad to learn that sweeps used to put ropes around the necks of geese and drop them into chimneys. The poor birds flapped their wings in panic and this cleaned the chimney. :(