L.S. DeLay
M.S. Foster
1998
<p><span>Seeds with ‘imitation arils’ appear wholly or partially covered by pulp or aril but actually carry no fleshy material. The mimetic seed hypothesis to explain this phenomenon proposes a parasitic relationship in which birds are deceived into dispersing seeds that resemble bird-dispersed fruits, without receiving a nutrient reward. The hard-seed for grit hypothesis proposes a mutualistic relationship in which large, terrestrial birds swallow the exceptionally hard mimetic seeds as grit for grinding the softer seeds on which they feed. They defecate, dispersing the seeds, and abrade the seed surface, enhancing germination. Any fruit mimicry is incidental. Fruiting trees of </span><span class="italic">Ormosia</span><span> spp. (Leguminosae: Papilionoideae) were observed to ascertain mechanisms of seed dispersal and the role of seemingly mimetic characteristics of the seeds in that dispersal. Seed predation and seed germination were also examined. </span><span class="italic">Ormosia isthamensis</span><span> and </span><span class="italic">O. macrocalyx</span><span> (but not </span><span class="italic">O. bopiensis</span><span>) deceived arboreally-foraging frugivorous birds into taking their mimetic seeds, although rates of seed dispersal were low. These results are consistent with the mimetic seed hypothesis. On the other hand, the rates of disappearance of seeds from the ground under the </span><span class="italic">Ormosia</span><span> trees, hardness of the seeds, and enhancement of germination with the abrasion of the seed coat are all consistent with the hard-seed for grit hypothesis.</span></p>
application/pdf
10.1017/S0266467498000303
en
Cambridge University Press
Dispersal of mimetic seeds of three species of Ormosia (Leguminosae)
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