Density compensation in neotropical primate communities: evidence from 56 hunted and nonhunted Amazonian forests of varying productivity

Abstract

Density compensation is a community-level phenomenon in which increases in the abundance of some species may offset the population decline, extirpation, or absence of other potentially interacting competitors. In this paper we examine the evidence for density compensation in neotropical primate assemblages using data from 56 hunted and nonhunted, but otherwise undisturbed, forest sites of Amazonia and the Guianan shields from which population density estimates are available for all diurnal primate species. We found good evidence of density compensation of the residual assemblage of nonhunted mid-sized species where the large-bodied (ateline) species had been severely reduced in numbers or driven to local extinction by subsistence hunters. Only weak evidence for density compensation, however, was detected in small-bodied species. These conclusions are based on the effects of ordinal measures of hunting pressure on the aggregate primate biomass across different size classes after controlling for the effects of forest type and productivity. These results are interpreted primarily in relation to patterns of niche partitioning between different primate functional groups or ecospecies. This study suggests that while overhunting drastically reduces the average body size in multi-species assemblages of forest vertebrates, depletion of large-bodied species is only partially offset (i.e. undercompensated) by smaller taxa.

Bushmeat hunting changes regeneration of African rainforests

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Dung beetle communities: a neotropical-north temperate comparison

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Ecological Correlates to Lemur Community Structure in Southeast Madagascar

“…Though it is ideal to measure the intensity of each response variable directly, many researchers use subjective measures or expert knowledge of anthropogenic disturbances in conservation biology (Bojorquez-Tapia et al, 2003;Ricketts and Imhoff, 2003;Ricketts et al, 1999) because of the difficulties in accurately measuring some variations, such as hunting pressures or a lack of time to conduct exhaustive scientific research or both (Davis et al, 1990). For example, Peres and Dolman (2000) used subjective measures of primate hunting pressures over a 100-yr period for 56 sites in Brazilian Amazonia. To reduce inaccuracies inherent in the subjective measures (Bojorquez-Tapia et al, 2003), only Lehman estimated intensities of anthropogenic disturbances.…”

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