Fruit advertisement strategies in two Neotropical plant-seed disperser markets

Mutualisms can be seen as biological markets in which participating species exchange resources and services. Advertisements like the colors fleshy fruits are commonly used to attract mutualistic partners such seed dispersers. Although advertisements are common, the strategies employed in partner attraction and shaping the diversity of advertisements such as fruit colors remain largely unknown. Here, we adopt a market perspective on fruit color advertisement in multi-specific ensembles of fleshy-fruited plants and their avian seed dispersers. We develop and test the following non-exclusive hypotheses about fruit advertisement strategies in two Neotropical plant ensembles: (1) some low-rewarding plants offering low-energy fruits have fruit advertisements indistinguishable from those of some highly rewarding ones offering high-energy fruits thus forming possible mimicry pairs; (2) highly rewarding plants advertise their fruits with distinctive colors; and (3) fruit colors indicate the type of nutrient offered. We find support for two of the advertisement strategies. Further, we discuss how constraints on signal diversity may affect the evolution of advertisement strategies and we provide a perspective on which processes could characterize plant advertisement strategies in the biological market of seed-dispersal mutualisms.