Scientists want to know what effect clearing forest for cattle farming is having on biodiversity in Colombia, so they’ve called on experts who know the various ecosystems intimately, birds. A dataset of 971 bird species across 13 regions helped them tell how ecosystems are changing.

Birds are indicators of forest health and survey for them can help ecologists cover greater areas than localised bioblitzes. When specialised forest birds disappear, they reveal the loss of complex plant communities in the forest, because if the plants were there, birds would have found them.

The study took six years tracking birds from the Amazon lowlands to Andean peaks, 4000 metres tall. Each elevation zone hosts unique plant communities that have evolved over millions of years. Tracking the birds over such varied landscape was difficult, so the team relied on more than eyes. 80% of the birds recorded as present were not seen in the survey. Instead they were identified from their birdsong. What the survey found was that Colombia still has incredible biodiversity; mountain forests ≠ lowland forests ≠ páramo grasslands. Each has entirely different species.