JAA has a very interesting article on stable oxygen and carbon isotope tests on scarlet macaws from Pacquime. (Anyone know how to add the accent on the last e? Anyone?):
Somerville, Andrew D, Ben A. Nelson, and Kelly J. Knudson
2010 Isotopic Investigation of Pre-Hispanic Macaw Breeding in Northwest Mexico. Journal of Anthropological Archaeology 29: 125-135.
To summarize briefly, the oxygen isotopes suggest most macaws were born and bred at the site, rather than imported from Mesoamerica. The carbon isotopes suggest that adult birds, at least, were fed mostly maize. The outliers were as interesting as the overall pattern. One bird, for example, appears to have come originally from a wetter, warmer climate, probably within the original range of the birds in Mesoamerica.
It's a great example of human manipulation, where prehistoric peoples extended the range (and diet!) of a species. I wonder what other species or sites could be investigated in this manner. As much as I would love to see this kind of analysis applied to the movement of domestic herd animals across Eurasia and Africa, sufficient chronological control is impossible. Macaws are an oddity in many ways: very long-lived animals that were kept alive for a secondary product (feathers), were traded in very small numbers, and were not clearly bred in captivity outside of a few centers. There aren't a lot of other cases like them.
There are on-going debates over the origin of macaws in the Southwest, of course, so it would be fascinating to see whether the oxygen isotopes suggested a Pacquime origin for birds in the Four Corners region. I assume such analyses are on-going.