Antonio:

There are a lot of options in Mexico, where native languages have been classified as 364 varieties belonging to 68 groups. How many languages there are depends on how you define language: what degree of intelligibility you requiere to say two varieties belong to the same language, and if you include other factors such as autoadscription by groups of speakers.

Here is the official catalog (you can use the link at the top of the page to download the complete document):

http://www.inali.gob.mx/clin-inali/

This is the book version of the same catalog:

http://site.inali.gob.mx/pdf/catalogo_lenguas_indigenas.pdf

And here is a study of endangered languages in Mexico:

http://site.inali.gob.mx/publicaciones/libro_lenguas_indigenas_nacionales_en_riesgo_de_desaparicion/libro_lenguas_indigenas_nacionales_en_riesgo_de_desaparicion.html

Catherine:

What you say is important. This perspective has been underutilized and promises to contribute greatly to our understanding of language in culture and environmental context.

Dear Catherine,

Thanks a lot for your insightful and stimulating reply. My field of expertise is language evolution (in truth my question was aimed to provide one student of mine a good target for her PhD thesis), but I'm really interested in this close link between biological diversity, social diversity, and linguistic diversity. Clearly, the role of the environment (broadly construed) and of cultural evolution in language evolution has been understimated over the years. I think the time has come to bring this link to the forefront of evolutionary studies.

Best,

Antonio

Dear David,

Thank you very much for these interesting links. It's clear to me that some of the endangered languages from Mexico can be a very good target.

Best,

Antonio

I think it's important to document as many as possible of the endangered languages.  But practically, it will make your work more interesting and have the possibility of actually helping to preserve a language if you pick one where there is a core of speakers who are actively working on preservation.  If you can then identify a mentor in this core, that is a person who (a) knows the language and the culture from the inside out and (b) is willing to work with you, you will have a much stronger basis from which to work.  Good luck!