As conservationists seek to maintain biodiversity levels in tropical coffee landscapes, data indicates the presence and quality of surrounding forest habitat may play a larger role than previously thought.
New research from the Colombian Andes shows that conserving forest cover across coffee growing landscapes is essential for sustaining diverse bird communities, even more than farm‑level shade tree management alone. The study, conducted by ecologists with SELVA and the Smithsonian's National Zoo and Conservation Biology Institute, examined how both landscape composition and local vegetation structure influence bird habitat use in one of the world's most important coffee‑producing regions.
The researchers found that forest cover within a 2‑kilometer radius positively predicted bird habitat-use across all ecological guilds, or organisms that use the same ecological resource in similar ways, including species of conservation concern. Regardless of their individual habitat preferences or foraging guilds, birds were more likely to be found in places with high levels of surrounding forest cover.
Forest‑dependent species were especially sensitive: they required at least 32% forest cover in the surrounding landscape to reach median occupancy levels. In contrast, generalist species were more flexible. They maintained median occupancy both in forest patches and in shade‑grown coffee with at least 10 tree species and 45% canopy cover. However, the study revealed a key interaction: as landscape forest cover declined, the amount and diversity of shade needed to maintain these birds on farms increased. In other words, coffee farms in deforested landscapes needed denser and more diverse shade tree canopies to support diverse bird communities.
Bird guilds responded differently to farm vegetation. Dense, diverse shade coffee supported generalists, frugivores, insectivores and nectarivores. Meanwhile, sun coffee—intensive monoculture with little or no shade—favored granivores and omnivores, as did early successional forest. Seasonal shifts also emerged, with many guilds increasing their use of forest habitats during December and January, which corresponds to a peak breeding period in this region. Because many species require different habitats in the breeding and non-breeding season, this finding highlights the importance of maintaining diverse habitat options in the landscape year‑round.
The authors conclude that forest conservation and shade‑coffee management are complementary, not interchangeable, strategies. Protecting and restoring forest cover sets an ecological foundation that allows farm‑scale practices to succeed. In the Eastern Colombian Andes, boosting forest cover would improve habitat suitability for nearly all bird groups, strengthening both the biodiversity and sustainability of coffee landscapes.
