DOI: 10.5061/dryad.6cd0v
title: Data from: Establishing macroecological trait datasets: digitalization, extrapolation, and validation of diet preferences in terrestrial mammals worldwide

description: Ecological trait data are essential for understanding the broad-scale
 distribution of biodiversity and its response to global change. For
 animals, diet represents a fundamental aspect of species’ evolutionary
 adaptations, ecological and functional roles, and trophic interactions.
 However, the importance of diet for macroevolutionary and macroecological
 dynamics remains little explored, partly because of the lack of
 comprehensive trait datasets. We compiled and evaluated a comprehensive
 global dataset of diet preferences of mammals (“MammalDIET”). Diet
 information was digitized from two global and cladewide data sources and
 errors of data entry by multiple data recorders were assessed. We then
 developed a hierarchical extrapolation procedure to fill-in diet
 information for species with missing information. Missing data were
 extrapolated with information from other taxonomic levels (genus, other
 species within the same genus, or family) and this extrapolation was
 subsequently validated both internally (with a jack-knife approach applied
 to the compiled species-level diet data) and externally (using independent
 species-level diet information from a comprehensive continentwide data
 source). Finally, we grouped mammal species into trophic levels and
 dietary guilds, and their species richness as well as their proportion of
 total richness were mapped at a global scale for those diet categories
 with good validation results. The success rate of correctly digitizing
 data was 94%, indicating that the consistency in data entry among multiple
 recorders was high. Data sources provided species-level diet information
 for a total of 2033 species (38% of all 5364 terrestrial mammal species,
 based on the IUCN taxonomy). For the remaining 3331 species, diet
 information was mostly extrapolated from genus-level diet information (48%
 of all terrestrial mammal species), and only rarely from other species
 within the same genus (6%) or from family level (8%). Internal and
 external validation showed that: (1) extrapolations were most reliable for
 primary food items; (2) several diet categories (“Animal,” “Mammal,”
 “Invertebrate,” “Plant,” “Seed,” “Fruit,” and “Leaf”) had high proportions
 of correctly predicted diet ranks; and (3) the potential of correctly
 extrapolating specific diet categories varied both within and among
 clades. Global maps of species richness and proportion showed congruence
 among trophic levels, but also substantial discrepancies between dietary
 guilds. MammalDIET provides a comprehensive, unique and freely available
 dataset on diet preferences for all terrestrial mammals worldwide. It
 enables broad-scale analyses for specific trophic levels and dietary
 guilds, and a first assessment of trait conservatism in mammalian diet
 preferences at a global scale. The digitalization, extrapolation and
 validation procedures could be transferable to other trait data and taxa.
description: Metadata for
 MammalDIET_v1.0A comprehensive global
 dataset of diet preferences of mammals (‘MammalDIET’). Diet information
 was digitized from the literature and extrapolated for species with
 missing information. The original and extrapolated data cover
 species-level diet information for &gt;99% of all terrestrial
 mammals.MammalDIET_v1.0.txt