How did the climate and landscape change when Bruce and the Yuko Indians travel to find the Motilone?

The climate and landscape change as Bruce and the Yuko Indians travel to find the Motilone. The sparse trees that are in the Andes became tall, close trees of a tropical jungle. There are vines hanging from trees, some of them as thick as a rope. Even the noises are different. Parrots scream, and monkey screech. It is also warmer than in the village in the Andes.