LOL!!! Well, I am always happy to answer questions about Porter City because it has been in my head literally every day for, like, five or six years now.
And it will make you happy to know that I am currently writing a short comic about Knox the fox that Miss Flatbear will be illustrating! Hopefully, it will be the first step in a series of Porter City stories; we’re actually thinking about making a Tumblr to house them all because people do seem pretty interested. :)
Now go write your paper, young lady, and stay off of Tumblr!
Well, basically the concept behind skin-walkers (which can be called skin-walkers, skinwalkers, shapechangers, shifters, and any number of other things depending on what culture they belong to, although amongst themselves they typically just refer to themselves as whatever animal they are, and refer to the non-changing animals as the “little cousins”) is that there is at least one for every animal in the world. Some animals, particularly the social ones that move in flocks or herds or other family groups, will have more than one skin-walker living in the same place, but the solitary ones tend to spread out. For example, you’ll only find one bear shifter in Porter City, but there are a whole mess of crow and rat shifters.
So yes, it is absolutely possible that there are birds of paradise skin-walkers! In their human forms, they would look roughly like whatever person they saw first. Since shifters are very, very old (in spite of the fact that many of them resemble children in age and behavior) this usually means whoever were the first people to settle whatever area they are from. For example, Porter City is in the Blue Ridge Mountains so most of the shifters that gravitated to the city appear Cherokee, though there may be variations in the colors of their hair or eyes; for example, the jays are very proud of their plumage so they have hair the same blue as their feathers.
So a bird of paradise shifter would appear ethnically Papuan, but depending on what species it actually was, it could project that through wild hair, tattoos, and flamboyant clothing.
They also tend to stick to their home turf, but some skin-walkers have been known to travel, particularly since the supernatural community was publicly outed. :)