If you’ve been birding for a while you’ve probably heard, even used, the word “primaries” but the word remiges could be new to you. It was to me.
Let’s tackle these two terms in reverse order since remiges are a more general term.
Remiges (pronounced REH.midg.iz) are the flight feathers on a bird’s wing, outlined in red in this picture.
Remiges include all the flight feathers – primaries, secondaries and tertials – and make up the entire trailing edge of the wing.
So what are the primaries?
Answer: David Sibley describes them as “flight feathers growing from the “hand” bones and forming the lower border of the folded wing.”
The snow goose is an easy example, a white bird with black primaries. I’ve circled his primaries in green above.
A quick way to think of primary feathers is that they’re where the bird’s fingers would be. The difference is that there are 9 to 11 of them, sometimes more depending on the species, so they extend around the lower edge of the wing. If you had 10 fingers on each hand, where would you put them? Probably where the bird puts his.
Primaries are easy to see on large birds in flight. Watch soaring red-tailed hawks and you’ll see that they spread their primaries and tip them up to reduce wingtip vortex. Aircraft engineers design upturned wingtips on airplanes for the same reason.
So… the primaries are feathers where the birds fingers would be, and all primaries are remiges (wing flight feathers) but not all remiges are primaries.