INTERSPECIFIC AND INTRASPECIFIC VARIATION IN FRUIT TRAITS IN COOCCURRING VERTEBRATE-DISPERSED PLANTS

A quantitative analysis of the patterns of intra- and interspecific va riance of fleshy fruit traits (length, width, pulp mass, seed mass, pe rcent pulp mass) in eight species of southeastern Spanish vertebrate-d ispersed plants, Berberis hispanica, Crataegus monogyna, Daphne laureo la, Hedera helix, Juniperus communis, Juniperus phoenicea, Juniperus s abina, and Rosa canina, shows a statistically significant individual v ariability in the five fruit traits considered. Individual variability tended to be largest for pulp mass and seed mass (coefficient of vari ation of individual means between 20% and 30%) and smallest for fruit width and length and for proportion of pulp (CV of 5%-12%). Most varia nce in fruit traits (67%-88%) was accounted for by taxonomic affiliati on, while the remainder of the variance was partitioned in roughly sim ilar proportions among and within plants of individual species. There were some differences between fruit traits in the relative proportion of variance contributed by within and among individual variation, but all fruits traits in all species consistently exhibited a remarkably h igh proportion of withinin-dividual variance, roughly comparable to th e variance among individuals. The potential ecological and evolutionar y implications of observed patterns of fruit variability are discussed in relation to the foraging behavior of seed-dispersing frugivores.