Continuous forest at higher elevation plays a key role in maintaining bird and mammal diversity across an Andean coffee-growing landscape

Shade coffee is among the most widespread and economically important crops in montane tropical regions and is considered more hospitable to wildlife than non-shaded crops. Questions remain regarding the value of shade coffee as habitat for wildlife, however, given the historical research focus on small-bodied and canopy species. Simultaneously, climate-driven upslope migration of coffee crops represents an emerging threat to well-conserved tropical montane forest at higher elevations. This study examined ground-dwelling birds and medium-large mammals in a shade coffee landscape of the Western Andes of Colombia. We asked the following questions: (1) How do bird and mammal occupancy, richness, and community composition change from continuous forest at higher elevations to middle-elevation forest fragments and shade coffee? (2) Do birds and mammals differ in their response to shade coffee? (3) Do high-elevation forests contribute to maintaining biodiversity in mid-elevation shade coffee? We sampled birds and mammals with camera traps in middle-elevation shade coffee plantations and forest fragments and in continuous forest further upslope. We then used a multi-species occupancy model to correct for imperfect detection and to estimate occupancy, richness, and community composition. Shade coffee lacked similar to 50% of the bird and mammal species found in continuous forest, primarily large-bodied and insectivorous birds and forest-specialist and large-bodied mammals. Forest fragment richness was closer to shade coffee than to continuous forest, but species composition significantly differed between coffee and both forest types. Birds in coffee plantations were generally a unique subset of disturbance-adapted specialists, whereas mammals in coffee were mostly generalists. Distance from continuous forest was the most important landscape-level predictor of occupancy for both taxa, suggesting that this forest plays a key role in maintaining biodiversity across the coffee landscape. Biodiversity conservation in shade coffee landscapes, therefore, will be ineffective unless linked to landscape-level initiatives that conserve higher elevation tropical montane forest.

Automated summary

The number and composition of birds and mammals in shade coffee landscapes in the Western Andes of Colombia differ from those in continuous forest, lacking certain species such as large-bodied, insectivorous birds and forest-specialist and large-bodied mammals. The richness of species in forest fragments is closer to that in shade coffee but differs significantly in species composition. The distance from continuous forest is the most important predictor for occupancy, suggesting that conserving higher elevation tropical montane forest is crucial for biodiversity conservation in shade coffee landscapes.