Treesearch

We evaluated the accuracy of a portable radio teIemetry system in an insular tropical rain forest in preparation for a long-term radio telemetry study of the critically endangered Puerto Rican parrot (Amazona vittafa). No significant differences were found among error biases when comparing receiver systems, transmitter heights, distances, and topographical inclinations. Error of bearings to transmitters placed at distances of 100 m and 200 m from receivers at ground and canopy levels averaged –1.12°. Error polygons ranged from 0.5 ha to 2.0 ha (at 100 m and 200 m distances, respectively)....

We studied home range and movements of 15 radio-marked, juvenile Puerto Rican parrots (Amazona vittata) fledging from wild nests during summer and fall, 1985-87. When juvenile parrots remained in the nest valley, home ranges during 1986 (x̄ = 32 ± 10 [SE] ha, n = 4) were larger (P = 0.0079) than during 1987 (x̄ = 13 ± 6 ha, n = 5). After radio-marked parrots integrated into adult flocks, home ranges during 1986 (x̄ = 1,075 ± 135 ha, n = 3) were similar (P = 0.10) to 1987 (x̄ = 416 ± 62 ha, n = 2). Juvenile parrots restricted their movements to nest valleys an average of 58 ± 29 days...

Many exotic tree species have been imported into Puerto Rico for their wood, fruit, and use as coffee shade and ornamentals. Some of these trees have naturalized (reproduced without human intervention) and some have escaped into natural forests. At least 118 exotic species are reproducing in Puerto Rico. Estimates are given for the general rate of spread and future abundance of each species as well as the environmental requirements. Species that are abundant, widespread, and competing in natural stands, as well as those likely to do so in the future, are identified.