I love the Quaker in the nest. I think they’re depicting a pair in an aviary.
I can find a lot of interesting species specific illustrations on ebay if I look in languages other than English. Quaker parakeets have many other names: mouse parakeet, widow conure, Grey breasted parakeet, fly parrot (the Latin name).
when I was looking for grad schools I wanted to go to u of California as they had an avian sciences phd program. My vet thought I could smuggle my Quaker in by calling her a brotogeris parakeet but I think even 20 yrs ago California was inspecting incoming traffic for produce and animals.