Looks like a mark on the lens to me.
You get reported drones (however dubious) at East Angllan airbases, and it’s looney tunes time as mass hysteria takes hold. The Russians, sorry, I mean, ‘a certain power’, our main hate focus at the moment, are blamed for starlings and dirty camera lenses.
It is reasonable to assume that ‘a certain power’ is monitoring military airbases in the UK, and has been doing so continually and successfully since 1945. It is also reasonable to assume that we are monitoring theirs. The Ukraine situation has taken us back to Cold War thinking and sabre-rattilng, and both us and the ‘certain power’ feel threatened.
They are, as my old dad said once, all our friends. The ‘certain power’ is a friend with a loaded gun at our heads, and the Americans are a friend with a fist clenched tightly around our bollocks ('grab ‘em by the balls, and their hearts and minds will follow’, Henry Kissinger),
The ‘certain power’ can and frequently does sail merchant ships into our ports in the normal course of trade, a good bit of our imported timber arrives this way. It can and does fly civil aircraft into our airports, both commercial and private, and it’s citizens invest in our businesses and own large amounts of property here. Again, this has been happening since 1945.
They even send naval ships on courtesy visits; I recall a male voice choir from one of their destroyers visiting Cardiff in the 90s busking in the town centre. They were bloody good, too, and we know a bit about male voice choirs in Wales…
If the sparrows were hostile drones, how could they possibly have flown from the ‘certain power’ across a border that is probably the most heavily monitored on the planet and then several hundred miles across Europe and the North Sea without detection? With all due respect to UKVeteran, it sounds a bit ‘reds under the bed’ to me! Aliens are actually more likely…