Who is Gauchos from The Voyage of the Beagle and what is their importance?

The gauchos of Padagonia fascinate and impress Darwin. Known for their excellent horsemanship, the gauchos use lassos and bolas to capture not only cattle but all sorts of animals, including human beings. The bola consists of two or three balls of iron, stone or wood encased in leather and tied together with lengths of leather rope. When thrown at the legs, the balls wind the leather rope tightly around the target.