I have been inventing bird names and my friends believe me

I know almost nothing about birds, but years ago I confidentally called one a “grey garden pipit” as a joke. My friends believed me.

Since then, I have invented names whenever someone points at a bird: river sparrow, red-capped hedge runner, northern crumb thief. Last weekend one friend corrected a stranger using a name I made up. I realised this has gone too far, but admitting it now means explaining at least twelve imaginery species. I may have accidentally created a very small school of fake ornithology.