Patterns of movement and seed dispersal of a tropical frugivore

Movement is a fundamental feature of vertebrate behavior and can modify pro cesses within populations and communities. Because tropical avian frugivore s disperse seeds of many plant species, the temporal and spatial patterning of their movement will influence seed distribution within a habitat. To da te, little is known about movement patterns of these birds. Here we conside r the movement of an understory frugivore, Mionectes oleagineus. Movements of 16 non-breeding females were monitored using continuous radio-telemetry to provide a general description of movement patterns and to examine the fr actal geometry of the spatial component of movement. Most movements were of short distance and duration, with the frequency distributions of both meas ures strongly skewed to the left. Over the range of measurement scales cons idered, the fractal dimension of M. oleagineus's movement increased with in creasing measurement scale up to ca. 100 m, whereafter it appeared to flatt en out. We combined movement data with M, oleagineus gut-passage rates for seeds of six plant species to predict seed shadows. Estimated seed shadows were leptokurtic for four of the six plant species, with median dispersal d istances for all species from 42 to 56 m. Dispersal distances were of the o rder of reported pollen dispersal distances, suggesting that even small see d dispersers Like M. oleagineus can provide significant dispersal for plant genotypes. Gut-passage rate appears to determine the shape of the seed sha dow, while movement determines dispersal scale.