Blue feathers, not blue jays

So, in my Veterans Day post I quoted Robert Graves' The Next War, which contains these lines:

From the first time you tear and slash
Your long-bows from the garden ash,
Or fit your shaft with a blue jay feather,
Binding the split tops together

I wondered at the time, are there really Blue Jays in England? Well, the answer is no. But there are jays, and some of their feathers are blue (though they're mostly sort of pink).
So this is a [blue [jay feather]] not a [[blue jay] feather].

Blue Jay	(Eurasian) Jay