They make up a skein (5)

I believe the answer is:

geese

(Other definitions for geese that I've seen before include "Six of these are 'a-laying' on 31 December" , "Large birds of the duck family" , "Water birds; fools" , "They come in gaggles and skeins" , "Birds that fly in a skein" .)

I've seen this clue in The Guardian.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.