Light as a Feather

I sent this pic as a quiz question this morning.

Niece R’s son A is 9 today, both living with grandma (my sister) who has really been getting into birds these last months.

The question being - what bird ? It’s built a nest here, not sure if they are still there (the recent weeks of continuing rain and high winds have not suited them). And it would never be seen on any of my sister’s bird feeders.

First suggestions were chicken (we don’t have those), peacock (their garden may be visited by one, no chance here), quail (my brother needs birding lessons) and owl (we’d be so lucky). All wrong. My sister got it when she joined the conversation.