Hola. Came across this site trying to look into my last name. My last name can be seen as a variation on Bojórquez. One of my uncles told me many years ago that my grandfather's grandfather and his brothers changed the spelling of their last name; most changed it to Bórquez. However, my particular ancestor changed it to Búrquez. I've come to the conclusion that they simplified the spelling of "Bohórquez", which at one time approximated the pronunciation of its variant "Bojórquez", but the "h" lost any remaining aspiration (becoming silent), so the pronunciation (these are all in Spanish of course)was almost the same as "Bórquez".The family was in Sonora, and as there were "Bohórquez" there, this seems like the most likely explanation of these variations.