My turn!

About five years after I'd started birding, my mother got a call from a
friend of hers. A bird she'd never noticed before had appeared in her yard.
Having heard me discuss field marks and the like, mom asked her for details
and phoned me to ask what I thought it might be.

David: Hello?

Mother: Hi. Claire phoned to tell me she's got an unusual bird in her yard
and wants to know what it is.

David: What does it look like?

Mother: It looks like a sparrow, but it's not.

David: (Choking and gasping noises)