"Jake" wrote
[...]
The male GSW has a distinctive red patch on the back of its head,
juveniles have a noticeable red cap which fades as they get older
(unlike the Greens who keep their red cap) and the adult female has no
red markings on the head.

That's what was mystifying me - both the adults have a noticeable red
head (as do both the juveniles). Maybe I've got a gay couple! Or two
related males who are leaving the females to their knitting while they
get on with the knocking?

Nooo, not knitting... they do tapestry.

--
Sue