Per your recent post, I could recommend David Bacab:

http://www.yucatanbirds.org.mx/ingles/agencias/guias.php

He lives near Celestun, on the other side of the Yucatan, but knows his birds well and may be able to come over to bird with you on the east side of the peninsula. You may want to consider extending your trip west, as there are lovely colonial towns in that part of Yucatan, and he can take you on a boat tour of flamingoes that would impress birders and non-birders alike. There are some endemics he can find for you over there as well. His English is very good.

Jack Stephens
jstephens62 at comcast.net
Edmonds, WA