Diversity, abundance and seasonality of birds in a Caribbean pine plantation and native broad-leaved forest at Trinidad, West Indies

Abstract

SummaryMonoculture plantations of exotic Caribbean pinePinus caribaeahave been planted extensively in many tropical countries, but little is known about the bird communities inhabiting them. From October 1995 to September 1996, we compared bird populations in a 37-ha stand of mature Caribbean pine forest (planted in 1972) with an adjacent, similar-sized stand of native broad-leaved forest at Mount Saint Benedict, Trinidad, West Indies. Ten censuses, each including 10 fixed-radius point counts (25 m radius, 10 minutes duration), were conducted simultaneously during different months of the year in each habitat. Both species richness and species diversity were significantly lower in the pine forest, but the overall abundance of individual birds did not differ between the two forests. Seasonal variation in bird populations was more pronounced in the pine forest, where fewer birds (and presumably food resources) were present during the dry season. The pine forest bird community was dominated by forest edge specialists and the native forest by forest interior specialists at both the individual and species levels. At the individual level, nectarivores, aerial foragers and understorey foragers were proportionately more common in the pine forest; insectivores and canopy foragers were more common in the native forest. At the species level, more aerial foragers occurred in the pine forest and more understorey foragers in the native forest. The diversity of bird communities in pine plantations may be promoted by increasing habitat heterogeneity.