What are these branching feathers called?

[DonyaQuick]

Is there a term for feathers where the is a smaller feather with its own narrow shaft branching off the main one? I've seen pictures of "double plume" emu feathers, but those seemed more symmetrical and couldn't' find any examples of the term applied to chickens, so I assumed it must be called something else. The picture below is from a feather that one of my 3-month-old Buff Orpingtons discarded recently; they are getting lots of feathers like this and I've just never seen this kind of thing in other birds I've kept in the past (mostly parrots and finches). I assume these feathers have something to do with cold hardiness since my chickens started getting cranky about temperatures over 80F as soon as the new feathers starting appearing in large numbers.

Also apologies if I put this thread in the wrong place; wasn’t really sure where it belonged.

 

[casportpony]

Very interesting, I've never seen that before.

 

[JacinLarkwell]

I always assumed they were normal feathers. That happens all the time with my birds

 

[DonyaQuick]

I always assumed they were normal feathers. That happens all the time with my birds

Is it a seasonal thing by chance? I kind of hope it is or my chickens are going to melt next summer - its not even a hot region, they just get hot so easily now that they're covered in these double feathers.

 

[JacinLarkwell]

Is it a seasonal thing by chance? I kind of hope it is or my chickens are going to melt next summer - its not even a hot region, they just get hot so easily now that they're covered in these double feathers.

I don't know. Usually they're just discarded feathers when I see them. I'm processing soon though, I'll see if my boys have any when I'm plucking