The effect of passage through the gut of the Greater Rhea (Rhea americana) on germination of tree seeds: implications for forest restoration

RENISON, D.; VALLADARES G.; MARTELLA M.B.

EMU

CSIRO PUBLISHING

Año: 2010 vol. 110 p. 125 - 131

0158-4197

Long-distance seed dispersal is an important process for maintaining genetic connectivity between forest fragments and for promoting fast re-colonization of deforested land. Based on the hypothesis that the Greater Rhea (Rhea americana), a large flightless bird native to South America, could play a major role as disperser of tree seeds, we evaluated whether seed passage through its digestive tract affected germination of six tree species native to central Argentina. We determined the proportion of seeds that germinated in a climate-controlled chamber for untreated (control) seeds, as found under seeder trees, seeds that passed through the digestive tract of captive Greater Rheas, and seeds treated with optimum pre-germination treatments. Our results showed that germination response to gut passage reached or surpassed the optimum germination treatments in three tree species, was similar to control treatments and lower than optimum treatments in two tree species, and lower than all alternative treatments in one tree species. We conclude that Greater Rheas are one of the few remaining native large-bodied animals with potential to effectively disperse seeds of large-sized fruit species, thus reinforcing the importance of restoring former Greater Rhea population sizes.