Cuyabeno Wildlife Reserve, Wildlife reserve in Sucumbíos Province, Ecuador

Cuyabeno Wildlife Reserve covers 590,112 hectares in Sucumbíos and Orellana provinces, sloping from about 326 m near the Andes down to under 177 m. Its poorly drained plain holds periodically flooded forests, black-water rivers such as the Cuyabeno and sediment-rich ones such as the Aguarico, plus semi-permanent lakes like Laguna Cuyabeno that usually partly dry out.

Decreed on 26 July 1979 under the FAO-based national protected areas strategy, the reserve first covered only the roughly 150,000-hectare Cuyabeno River watershed. After an invasion of the upper watershed, director Flavio Coello and Daan Vreugdenhil proposed excluding the invaded zones and extending the reserve to the Peruvian border, bringing it to 590,112 hectares in 1983.

Indigenous communities in the area draw on inherited knowledge about medicinal plants, sometimes showing visitors how bark and roots are used in traditional healing. Many residents continue to perform ceremonies tied to seasonal changes and forest cycles.

Access usually involves reaching Lago Agrio by flight or overland bus from Quito, followed by a transfer to the reserve entrance. Visitors should plan for a multi-day trip, as exploring the sprawling waterways and trails takes time.

Rivers in this area show different colors: white-water rivers carry muddy sediment from the Andes, while black-water rivers appear dark because of decomposed plant matter. These chemical differences influence which fish species live in each type of waterway.