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 multivraiate 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.