Avian Resource Use in a Caribbean Pine Plantation

Abstract

I studied resource use by birds in a Caribbean pine (Pinus caribaea) plantation in Luquillo Experimental Forest, Puerto Rico, from 1981 to 1986. I used multivariate analyses to quantify and provide a classification of foraging relationships among bird species. The analysis of food-searching behavior by birds indicated that resource use was closely associated with vegetation physiognomy. The presence of specific kinds of vegetation was important in determining the presence and abundance of some bird species. Frugivores and nectarivores foraged in understory flowering and fruiting shrubs. Among insectivores, foliage-gleaners were found mainly in the canopy and hoverers were concentrated in the understory. Dead hanging leaves and vine thickets provided important foraging substrates for some species. Forest managers can improve habitat for birds in plantations by providing habitat heterogeneity through maintenance and encouragement of understory vegetation diversity, vine thickets, and native upperstory trees. J. WILDL. MANAGE. 52(2):274-279 Information on the impacts of land management practices on neotropical birds, and particularly the changes that occur when heterogenous tropical forest ecosystems are converted to pine plantations, is limited. In Australia, exotic pine (Pinus radiata) plantations supported 50% of breeding bird species found in the original eucalyptus forests (Gepp 1976, Suckling et al. 1976, Driscoll 1977). Only Falkenberg et al. (1983) has investigated bird communities in neotropical pine plantations; they found fewer birds in Caribbean pine plantations than in native forest sites in Jamaica. Resource use by birds in neotropical pine plantations has not been quantitatively examined. Information on bird use of neotropical pine plantations is needed because 33% of all tropical plantations are in the neotropics and the most commonly planted species are pine (Pinus spp.) (Evans 1982). The objectives of my research were to describe avian resource use in a Caribbean pine plantation and analyze niche structure, food resource relationships, and other factors associated with the bird assemblage patterns. This study was conducted under the auspices of the Institute of Tropical Forestry, U.S. Forest Service, Puerto Rico, and the U.S. Man and the Biosphere Program on Tropical Forests. I am indebted to A. E. Lugo for guidance, cooperation, and helpful suggestions. I also profited from discussions with W. J. Arendt, G. P. Bauer, C. E. Bock, B. B. Cintron, C. A. Delannoy, J. C. Figueroa, G. E. Freeman, J. A. Moreno, T. K. Nakamura, T. R. Strong, F. H. Wadsworth, P. L. Weaver, and J. W. Wiley. I gratefully acknowledge the valuable field assistance of A. Arendt, W. J. Arendt, and E. Hernandez-Prieto and the forest structural information provided by A. E. Lugo. Financial support came from a National Research Council (Ford Found.) Postdoctoral Fellowship, Grant-in-Aid from the University of Colorado, and a National Geographic Society Grant.