Bird jammed a cooker hood,vented into an old chimney.I know how a chimney sweep feels after getting a facefull of soot.
The birds (good film) had totally blocked the chimney further up so over to the builders,good luck.
Putting my skills on ‘Ornithology’ to the test I would say it was a ‘Bald-headed Sootybird’ renowned for it’s distinctive high-pitched call…‘Sweeeeep!….Sweeeeep!’ They are usually most active around lunch & dinner time circling high above the chimney tops.