Mammal population densities at a global scale are higher in human-modified areas

  • Global landscapes are changing due to human activities with consequences for both biodiversity and ecosystems. For single species, terrestrial mammal population densities have shown mixed responses to human pressure, with both increasing and decreasing densities reported in the literature. How the impacts of human activities on mammal populations translates into altered global density patterns remains unclear. Here we aim to disentangle the effect of human impacts on large-scale patterns of mammal population densities using a global dataset of 6729 population density estimates for 468 mammal species (representing 59% and 44% of mammalian orders and families). We fitted a mixed effect model to explain the variation in density based on a 1-degree resolution as a function of the human footprint index (HFI), a global proxy of direct and indirect human disturbances, while accounting for body mass, trophic level and primary productivity (normalized vegetation index; NDVI). We found a significant positive relationship between population density and HFI, where population densities were higher in areas with a higher HFI (e.g. agricultural or suburban areas – no populations were located in very high HFI urban areas) compared to areas with a low HFI (e.g. wilderness areas). We also tested the effect of the individual components of the HFI and still found a consistent positive effect. The relationships remained positive even across populations of the same species, although variability among species was high. Our results indicate shifts in mammal population densities in human modified landscapes, which is due to the combined effect of species filtering, increased resources and a possible reduction in competition and predation. Our study provides further evidence that macroecological patterns are being altered by human activities, where some species will benefit from these activities, while others will be negatively impacted or even extirpated.
Author:Marlee A. Tucker, Luca Santini, Chris Carbone, Thomas MuellerORCiDGND
Parent Title (English):Ecography
Place of publication:Oxford [u.a.]
Document Type:Article
Date of Publication (online):2020/09/29
Date of first Publication:2020/09/29
Publishing Institution:Universitätsbibliothek Johann Christian Senckenberg
Release Date:2022/03/22
Tag:Anthropocene; abundance; demography; human footprint; landscape fragmentation; terrestrial mammal
Page Number:13
First Page:1
Last Page:13
Data available from the Dryad Digital Repository: <> (Tucker et al. 2020).
MAT and TM were supported by the Robert Bosch Foundation and MAT was additionally supported by the Goethe International Postdoctoral Programme, People Programme (Marie Curie Actions) of the European Union's Seventh Framework Programme FP7/2007–2013/ under REA grant agreement no. [291776] and a Radboud Excellence Initiative Fellowship.
Dewey Decimal Classification:5 Naturwissenschaften und Mathematik / 57 Biowissenschaften; Biologie / 570 Biowissenschaften; Biologie
Licence (German):License LogoCreative Commons - Namensnennung 4.0