Sesame Street: Bert and Ernie's Great Adventures S01 E06 Rainforest

As ecologists, Bert and Ernie must preserve and protect the plants and animals of the rain forest. Unfortunately, this rain forest has a displaced beaver with the ambition to build a Grand Opera House! It's up to Bert and Ernie to convince the beaver the importance of the rain forest before he gnaws down all the trees for his Opera House.