What are the apperance differances from each. I look at pictures and they do seem to look a like. Can someone help some the differances?

With my limited knowledge, I believe the biggest one is the coloration of the tail and inner ring of tail feathers. The Merriams are more white while the Rio Grande is usually a darker coloration. I could be completely wrong on this but that is my understanding.

Here is my Merriam that I shot last year. As you can see, the tail feathers are bright white, while typical Rios have a brown or darker brown tail tips.

Thanks and that is what I was looking for. They are very close in pattern of tail feathers but white and buff on tips are the only differance is what I can see. I have shot both and they are all most the same except for that.

Merriams got more purple... Rios got alot of green irredescance