Fieldfares and mistlethrushes are well known blackbird-sized odd noise makers, and in cold weather mistlethrushes tend to be seen in places they are not usually seen. At a glance, mistlethrush looks generally brown like a thrush or a Mrs Blackbird. Fieldfare looks generally grey.

99.9999% of winter hoopoe reports turn out to be jays, and 99.9999% of winter golden oriole reports turn out to be green woodpeckers. Nightjars are even harder to spot than those, so 99.9999% of winter nightjars are not nightjars also, especially in a part of the country nightjars are rarely found. Nightjars are not just rare, localised, migratory, like the previous, they are nocturnal. They specialise in lowland heath, and the heaths of central East Angular are their UK stronghold. I have a friend who has published many professional-quality bird photos on the web, including some rather lovely pictures of mistlethrushes and fieldfares there under "Birds of Wayside and Woodlands" Zenfolio | James Gibbs if you want to check them out. He has photos of many hard-to-see things, including hoopoes, but no nightjars: they are very hard indeed.