Ap. Lima et We. Magnusson, PARTITIONING SEASONAL TIME - INTERACTIONS AMONG SIZE, FORAGING ACTIVITY AND DIET IN LEAF-LITTER FROGS, Oecologia, 116(1-2), 1998, pp. 259-266
This study investigates hypotheses about partitioning of food resource
s among all species and several size classes in an assemblage of diurn
al leaf-litter frogs in central Amazonia. All species in this assembla
ge change the type and size of prey as they grow. An ordination of die
t composition was significantly associated with frog size and species-
specific behaviour. However, a partial Mantel analysis indicated that
species explained about 1.5 times more of the variation in diet overla
p between individuals than frog size. Diet and foraging activity are c
orrelated in juveniles, but not in adults, and this result holds wheth
er species are considered as statistically independent observations or
whether relationships are analysed using phylogenetically independent
contrasts. This study showed that the partitioning of food resources
between species changes with the population size structures. Thus, int
raspecific and interspecific changes in diet, coupled with different p
atterns of juvenile recruitment, cause diet segregation among species
due to temporal segregation of equivalent size classes.