Management Effects on Hummingbird Abundance and Ecosystem Services in a Coffee Landscape

Abstract

Birds provide critical ecosystem services to farmers including pollination and biological control. Yet, birds are sensitive to the habitat degradation that often results from agricultural intensification. Given this, we aim to understand the ecological role of hummingbirds on coffee farms and how they are affected by coffee management practices. Hummingbird abundance was measured across a gradient of coffee production intensity in Chiapas, Mexico and we investigated how their density was affected by a range of management practices, including shade cover, agrochemical use, flower abundance and vegetation complexity. We also observed hummingbird foraging behavior to gauge their role in pollination and pest control. Hummingbirds were significantly more abundant on shade coffee sites compared to sun coffee sites, though sun coffee production did not present a significant barrier to hummingbird movement across the landscape. Floral availability, and specifically the abundance of a single species in the Bignonia genus, was the best predictor of hummingbird abundance. Available flowers were often lianas or epiphytes found growing on upper canopy trees scattered throughout the coffee farms. The resident hummingbird community was dominated by a single generalist species, the blue-tailed hummingbird (Amazilia cyanura), with low densities of three other species. Blue-tailed hummingbirds were observed foraging for insects within the coffee layer, as well as visiting the flowers of native, ornamental and crop species. Given the high overall density of hummingbirds in the landscape, it is possible that hummingbirds play a significant role in both pollination and pest control. To promote hummingbirds and their associated ecosystem services, we suggest coffee farmers retain some upper canopy trees in their coffee plots and allow them to accumulate flowering lianas and epiphytes. This low-cost, low-effort management recommendation could enhance coffee yield in low-intensity systems with benefits to hummingbird conservation, and forest bird conservation in general.