With wetland making up 90% of its territory, Laguna de Sonso is a premier destination for birdwatchers. This reserve is a migratory stop-off point for greyish piculet, blue-winged teal and many other birds. The migratory birds arrive from the northern hemisphere between September and October, and remain in the reserve until February. A remarkable variety of mammals, fish and reptiles has also settled in the marshland.