Is Yodelers a Word?

yo′del•er, n.

Is Yodeler a Scrabble word?

YODELER is a valid scrabble word.

What are Yodelers called?

Yodeling (also jodeling) is a form of singing which involves repeated and rapid changes of pitch between the low-pitch chest register (or "chest voice") and the high-pitch head register or falsetto.