Effects of bird ingestion on seed germination of four woody species of the temperate rainforest of Chiloé Island, Chile

We study the effect of ingestion by birds on seed germination and the consequences of absence of dispersal, with the persistency of the seeds inside the fruit. We collected seeds of four woody species of the temperate rainforest of Chiloé: Gaultheria mucronata, Luma apiculata, Myrteola nummularia, and Myrceugenia planipes. The seeds tested had the following origins: 1) Ingested seeds: seeds collected from the feces of birds, 2) Extracted seeds: seeds obtained directly from the fruits, and 3) Intact fruits: fruits collected directly from the plants. Germination of Myrceugenia planipes under greenhouse conditions, Luma apiculata, and Myrteola nummularia under laboratory conditions, and Gaultheria mucronata under both conditions was analyzed. We found that the seeds reach their maximum germination between 15-20 days after sowing, with the exception of those of G. mucronata sown in the greenhouse, which showed a low germination rate. In the greenhouse assay, seeds of G. mucronata ingested by birds, seeds extracted manually from the fruits, and seeds inside the fruits did not show significant differences in their germination percentages. In the laboratory assays, the seeds of G. mucronata and M. nummularia ingested by birds and the seeds extracted manually from the fruits also did not show any significant difference in germination. Under laboratory conditions, the seeds of L. apiculata ingested by birds presented a statistically greater percentage of germination than the seeds extracted manually. Under greenhouse conditions, seeds of M. planipes ingested by birds did not present a statistically different germination percentage from those seeds extracted from the fruits. The seeds of M. planipes, and L. apiculata inside the intact fruits did not germinate. We conclude that birds do not affect the seed viability of any of the four species studied.