The cascading effect of mammal species defaunation on seed and seedling survivorship as a result of hunting

Abstract

This study examines the interactions between a common palm species of submontane neotropical forests, the Chonta palm (Astrocaryum gratum) and the mammal community affected by human hunting. I worked in forests with different levels of hunting: Unhunted (Madidi National park), Hunted forest, Moderately hunted forest (near the indigenous community Asuncion del Quiquibey) where by interviewing one hunter per family and by using trap tracks, I determined that locals perceived mammal prey as abundant; and, similar to other sites, ungulates especially white-lipped peccaries were the preferred species. This is the first study detailing the germination and phenology of this palm which fruits twice a year, providing an important food resource for many species. I found that in the absence of the main seed and seedling depredator, the white-lipped peccary, seed survivorship increased; so that seedling survivorship was correspondingly high. In unhunted forest where this peccary was present, survivorship was lower. My results present new evidence that the hunting on medium to large mammals and, especially the presence of a main depredator, have a direct effect on A. gratum and ultimately affects forest structure.