Laguna de Sonso

The Cauca valley floor was once a mosaic of oxbow lakes, marsh and gallery forest along the river, and almost all of it was drained and levelled for sugarcane through the twentieth century - Sonso is what survives, a few thousand hectares of open water, reed and swamp forest, and it functions as a refuge for what the valley used to hold. The bird list runs to around three hundred species with migratory ducks and waders in the northern winter, and it holds the Apolinar's wren and other species under pressure. It is a Ramsar site. Threats are continuous: water abstraction, agricultural runoff from the surrounding cane, sedimentation and encroachment on the margins have all reduced and degraded it, and legal fights over its boundary have run for years.

What's there

• The last major wetland on the valley floor - the rest became cane.
• Around three hundred bird species - with northern migrants in winter.
• Open water, reed and swamp forest - what the valley once was.
• Continuous pressure - runoff, abstraction and encroachment.

When to go

December to March; early morning for birds. Half a day.

Practical notes

It is a birding site - without binoculars there is little. Access points are informal and a guide helps. Heat on the valley floor is heavy. The reserve is degraded and surrounded by industrial agriculture.

Nearby

Buga is east; Cali is south.

Key facts