DISPERSAL AND GERMINATION OF SEEDS INGESTED BY CARNIVORES IN THE ZAPOTITLAN DE LAS SALINAS VALLEY, MEXICO

Seed dispersal by animals influences plant recruitment depending on the number of dispersed seeds, the treatment given to seeds in the gut, and the probability of seed germination and seedling survival in the sites where seeds are defecated in the field. Seed dispersal by carnivores influences plant recruitment in temperate and tropical ecosystems. However, data on seed dispersal by carnivores in tropical drylands is limited. In these ecosystems, plants produce large numbers of fruits that may be eaten by carnivores, yet we ignore whether seed dispersal potentially influences plant recruitment. Hence, we evaluated the number of seeds dispersed by carnivores, the germination proportion after gut passage, and the types of sites where carnivores defecated seeds in the Zapotitlan de las Salinas Valley. We collected 384 scats to quantify the number of seeds per scat, the percentage of damaged seeds per scat, and the number of scats per site. We also compared the germination proportion between seeds removed from fruits and scats in laboratory experiments. We found seeds from 18 plant species. The scats had 133.1 ± 262.8 seeds from 1.4 ± 0.6 plant species, and 3 ± 12% of damaged seeds. The scats were dropped more frequently than expected in rocky areas and less frequently than expected in open and canopy areas. The gut passage had positive effects on germination in two species, neutral effects in six species, and negative effects in four species. These results suggest that seed dispersal by carnivores can potentially influence the recruitment of several plant species in the Zapotitlan de las Salinas Valley.