How to be a Fig

Abstract

The 900-odd species of Ficus (20, 21) constitute the most distinctive of the widespread genera of tropical plants. Figs have (a) a complex obligatory mutualism with their pollinating agaonid fig wasps, yet are found in almost all tropical habitat types and geographic locations [this sets them apart from ant-acacias (63-65), euglossine-orchids (24,26), moth-yuccas (45, 88, 89,), ant-epiphytes (66, 98) and ant-fungi (109)]; (b) fruits eaten by a large variety of vertebrates, most of which appear to be fig seed dispersers rather than seed predators; (c) minute seeds despite the adults’ long-lived woody life form; (d) exceptionally numerous congeners in almost any mainland tropical forest habitat; (e) every woody life-form (deciduous, evergreen; tree, strangler, epiphyte, vine, scandent shrub, bush); (f) intra-population inter-tree asynchronous flowering and fruiting in many habitats, yet strong intra-tree synchronous flowering and fruiting; (g) heavy outcrossed pollination even when the density of flowering conspecifics is extremely low; (h) no inter-specific competition for pollinators within a habitat irrespective of the number of Ficus species present and the timing of sexual reproduction; (i) heavy visitation of fruiting crowns by seed dispersers even when the density of conspecifics is extremely low; and (j) over 50% predispersal seed predation of all seed crops. There is a voluminous literature on the taxonomy and biology of fig flowers, fig fruits, and fig wasps (see reviews in 1, 9, 16, 20-22, 34-36, 41, 47, 52, 86, 90-96, 101, 112, 113), but each author focused on particular aspects of the system. Here I stress interactions among many parts of the system. Wiebes’ chapter in this volume is the most recent review of the details of the interaction of fig wasps with figs. However, a very brief overview of fig biology is useful here. First, ignore the atypical commercial fig, Ficus carica, since it occupies extra-tropical to sub-tropical habitats, has decidu-