Sth Amer field guide

[(Sally Stephens)]

     Can anyone recommend a good field guide to the birds of Sth and Central 
     America and Mexico? I will be going there in February, and will be 
     travelling from Patagonia to Mexico. I will be travelling light, so do not 
     want to get a book for every country. I am an enthusiastic but not a 
     fanatic birder - ie I won't be seeking rare vagrants or aberrant colour 
     morphs or trying to better someone else's sighting records (in fact, I 
have 
     no clue how many species I have seen - it is irrelevant to me). I just 
want 
     to get to know the birds as I travel and be able to recognise them. 
     
     So any advice will be welcome.
     
     Cheers - Sally Stephens