What determines the structure of the ungulate community in northernmost Brazilian Amazonia: habitat complexity or hunting impact?

Abstract

Hunting has a profound impact on ungulates, reducing their richness, diversity, and abundance. We surveyed ungulates in one protected, and two impacted areas of northernmost Brazilian Amazonia. Using nine line transects, during the dry seasons of 2010 and 2011, we surveyed 1,248.7 km. We also collected: density and dominance of trees, basal area, canopy height, and % of flooded forest in each of the studied transects. We calculated encounter rates, relative abundance, and biomass. We carried out ANOVA to test differences in the environmental parameters between the areas; t-test to test if ungulate community structure varied as a function of hunting in the two impacted areas; NMDS to test for possible differences in ungulate abundance within each area, as well as between the three areas; CCA was used to test the influence of the environment variables on ungulate abundance in the three areas, and determine if any of the ungulate species were associated with any of these variables. Encounter rates were higher in the impacted area, while biomass was higher in the protected area. Areas with similar hunting impacts and different vegetation formation clustered together, showing that hunting impacts shape regional mammal community composition.