Yes, DUNLIN is a Scrabble word!

Letter values in Scrabble US: D 2, U 1, N 1, L 1, I 1, N 1.

Is it a valid word?

DUNLIN is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

small common sandpiper that breeds in northern or Arctic regions and winters in southern United States or Mediterranean regions

Also: red-backed sandpiper, erolia alpina.