Bird populations in rustic and planted shade coffee plantations of eastern Chiapas, Mexico

Much of the remaining "forest" vegetation in eastern Chiapas, Mexico is managed for coffee on. In this region coffee is grown under either the canopy of nat ural forest or under a planted canopy dominated by Inga spp. Despite the large differences in diversity of dominant plant species, both planted and rustic shade coffee plantations support a high overall diversity of bird species; we recorded approximately 105 species in each plantation type on fixed radius point counts. We accumulated a combined species list of 180 species on repeatedly surveyed transects through both coffee plantation types. These values are exceeded regionally only by moist tropical forest. Of the habitats surveyed, shade coffee was second only to acacia groves in the abundance and diversity of Nearctic migrants. The two plantation types have similar bird species lists and both are similar in composition to the dominant woodland-mixed pine-oak. Both types of shade coffee plantation habitats differ from other local habitats in supporting highly seasonal bird populations. Survey numbers almost double during the dry season-an increase that is found in omnivorous migrants and omnivorous, frugivorous, and nectarivorous resident species. Particularly large influxes were found for Tennessee warblers (Vermivora peregrina) and northern orioles (Icterus galbula) in Inga dominated plantations.