In what countries or regions is culebra favored over serpiente when referring to a snake?
Hay muchas víboras/serpientes/culebras en el monte.
Welcome to the Forum, bdsmith!
The three words you are asking about are slightly different from each other, just like the English words: vipers, serpents and snakes. So they would be used in different contexts. I'm not sure if one is favored over another simply by region, although it is possible. Here are links to the SpanishDict definitions:
And here is the RAE definition of each word:
In those definitions you'll see notes indicating whether it is used a certain way by region.
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