Removal of Wild Nutmeg (Virola Surinamensis) Crops by Birds

摘要: We observed birds and mammals visiting individual plants in a Panamanian population of the rainforest tree Virola surinamensis ("Wild Nutmeg") to determine (1) relative importance different dispersal agents, (2) relationships between crop size, quality, seed removal. Arils this are exceptionally nutritious (63% fat, 9% nonstructural carbohydrate, 3% protein), but draw remarkably few species fruit-eating animals. Six take 77% seeds handled by One toucan (Ramphastos swainsonii) accounts for 35% handled; other (Penelope purpurascens, Trogon massena, Baryphthengus martii, Pteroglossus torquatus, Ram- phastos sulfuratus) play lesser roles. The smallest visitor, cotinga (Tityra semifasciata) eats arils does not disperse seeds. monkey (Ateles geoffroyi) removes frugivores, smells rejects or otherwise wastes 9%. Such small assemblage is anomalous forest with at least 78 animals; trees arillate similar size as many 23 frugivores. hypothesize that limited perhaps defensive compounds arils. Despite assemblage, an average 62% (range: 13-91%) fruits available animals taken. Fruits so both large crops depleted; no variance percentage removed can be attributed size. do vary size; 59% variation taken mean Fruit-eating preferentially deplete seeds, coincidentally favor high aril-to-seed ratios. No significant portion "dispersal success" explained aril mass alone. consistent differences could result dramatic dispersal, hence reproduction, over lifetime trees. On hand, selection may alternatively dispersability years when frugivores abundant, enhanced seedling vigor parental stand scarce. Small-seeded likely colonize new sites; large-seeded individuals produce offspring fare well competition seedlings near parent