Foraging behavior and food resources of forest-associated birds in coffee agroecosystems

Shade-grown coffee has received considerable attention in the conservation literature, particularly for its demonstrated benefit of providing habitat for Neotropical migratory birds. Some forest-associated Neotropical resident species also benefit from shade coffee, especially in the face of increasing forest loss within much of their range. Canopy management and structural complexity vary greatly in shade coffee production, and this variation likely produces changes in habitat quality for forest birds, including availability of food resources. To evaluate food availability in two farms with different shade management, two variables of foraging behavior were measured—attack rate and foraging speed—in two forest-associated species, the Yellow-green Vireo (Vireo flavoviridis) and the White-winged Tanager (Spermagra leucoptera). Foraging behavior was compared with body condition measurements to determine if there was a relationship between these various indices of habitat quality. Significant differences were found in foraging behavior of birds between the farms that suggest differences in habitat quality in terms of food resources. These differences appear to be corroborated by measurements of furcular fat deposits, but not by mass/physiological size measurements. These results may be helpful in understanding the patterns of avian diversity that have been documented in coffee management systems in the Neotropics, as well as assessing the conservation value of shade-grown coffee for forest resident species.