Influences of Fruit Diversity and Abundance on Bird Use of Two Shaded Coffee Plantations

Authors

  • Tomæs A. Carlo,

    Corresponding author
    1. Department of Zoology and North Carolina Fish and Wildlife Cooperative Research Unit, North Carolina State University, Raleigh, North Carolina 27695, U.S.A.
    2. Ecology and Evolutionary Biology Dept., University of Colorado, Boulder, Colorado 80309-0334, U.S.A.
      Corresponding author: Herbario Jardín Botænico de Puerto Rico, Unversidad de Puerto Rico, P.O. Box 364984, San Juan, Puerto Rico 00936–4984, U.S.A. e-mail: carlo@colorado.edu
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  • Jaime A. Collazo,

    1. Department of Zoology and North Carolina Fish and Wildlife Cooperative Research Unit, North Carolina State University, Raleigh, North Carolina 27695, U.S.A.
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  • Martha J. Groom

    1. Department of Zoology and North Carolina Fish and Wildlife Cooperative Research Unit, North Carolina State University, Raleigh, North Carolina 27695, U.S.A.
    2. Interdisciplinary Arts and Sciences, University of Washington, Bothell, and Department of Biology, University of Washington, Seattle, Washington 98195, U.S.A.
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  • 1

    Received 14 May 2003; revision accepted 3 June 2004.

Corresponding author: Herbario Jardín Botænico de Puerto Rico, Unversidad de Puerto Rico, P.O. Box 364984, San Juan, Puerto Rico 00936–4984, U.S.A. e-mail: carlo@colorado.edu

Abstract

ABSTRACT

We studied avian foraging at two shaded coffee plantations in Ciales, Puerto Rico. Both coffee plantations contained patches of second-growth forest but differed in shade types; one was a rustic plantation with a species-diverse shade including many fruiting plant species and the other was a commercial polyculture shaded almost solely by Inga vera. We quantified foraging activity of five fruit-eating bird species (Euphonia musica, Loxigillaportoricensis, Nesospingusspeculifirus, Spinetalisportoricensis, and Vireo altiloquous) and monthly fruit abundance in the coffee plantation and adjacent second-growth forest habitats at each site. Fruits comprised more than 50 percent of the diets for four of five focal bird species. We found a significant difference in the number of foraging records for focal bird species between coffee and forest habitats in the commercial polyculture but found few differences between these habitats in the rustic coffee farm. Overall, foraging activity was positively correlated with the abundance of fruits across study sites. Bird foraging was concentrated on plant species in the genera Cecropia, Miconia, Schefflera, Phoradendron, and Guarea, which together accounted for over 50 percent of frugivory records. Plant species in such genera fruited over prolonged time periods and provided birds with a fairly constant fruit supply. Our findings underscore the importance of fruiting plant species in making coffee plantations suitable habitat for birds and suggest that native fruiting plants be incorporated in coffee farms for avian conservation.

RESUMEN

Estudiamos el forrajeo de aves frugivoras en dos plantaciones de café de sombra en Ciales, Puerto Rico. Ambas plantaciones contenian parches de bosque de crecimiento secundario, pero se diferenciaban por el tipo de sombra: una era “rustica” con una gran diversidad de especies de sombra, incluyendo muchas especies de plantas frutales, y la otra era un “policultivo comercial” sombreada casi linicamente por Inga vera. En cada sitio, cuantificamos la actividad de forrajeo de cinco especies de aves frugivoras (Euphonia musica, Loxigilla portoricensis, Nesospingus speculiferus, Spindalis portoricensis, Vireo altiloquous), y la abundancia mensual de frutos en los cafetales y en los bosques adyacentes. Las frutas comprendieron más del 50 por ciento de la dieta de cuatro de las cinco especies de aves en estudio. Encontramos diferencias significativas en el nümero de registros de forrajeo de especies de aves entre los habitats de café y bosque en el policultivo comercial, pero encontramos pocas diferencias entre estos habitats en la granja de café rüstico. En general, la actividad de forrajeo estuvo positivamente correlacionada con la abundancia de frutos a través de los sitios de estudio. El forrajeo de las aves estuvo centrado en especies de plantas de los géneros Cecropia, Guarea, Schefflera, y Phoradendron, que juntas abarcaron por encima del 50 por ciento de los registros de frugivoria. Especies de plantas en estos géneros fructificaron por un penodo de tiempo más prolongado y surtieron constantemente a las aves de frutas. Nuestros hallazgos resaltan la importancia de las especies de plantas frutales en convertir las plantaciones de café en hábitats adecuados para las aves, y sugiere que las plantas frutales nativas deberian ser incorporadas en las granjas de café para la conservación de las aves.

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