Search the internet or local library
I’m sure everyone knows by now that you can pretty much research any subject nowadays wtihout ever leaving your computer. If you haven’t already, try Google image search. It’s great, I commonly go there looking for mainly animals & plants and the number of images offered are amazing. You could type something like “spangled drongo” and have dozens of images of the bird to consider – actually I checked & there were 31 images on the first 2 pages alone. There’s also sites like istockphoto.com where you can buy images quite cheaply for use in you artwork without royalties. Wherever possible, I try to use my own photos, but the internet is certainly a great backup source.
And then there’s your local library which of course has tons of reference books, but will usually also have more resources than just books. Our local library has heaps of local historical information & the librarians are only too happy to help dig up what you want.
The work shown is Kokopelli and the smaller photos are pictures I got from the net. I also read a fair bit about the mystical figure from North American Indian Culture & the concept that stuck was how he brought spring (starting right in the mural) in from winter (over to the left). I had him going the opposite direction to add a bit of Southern Hemisphere flavour to the work