Environmental context shapes the relationship between grass consumption and body size in African herbivore communities

Though herbivore grass dependence has been shown to increase with body size across herbivore species, it is unclear whether this relationship holds at the community level. Here we evaluate whether grass consumption scales positively with body size within African large mammalian herbivore communities and how this relationship varies with environmental context. We used stable carbon isotope and community occurrence data to investigate how grass dependence scales with body size within 23 savanna herbivore communities throughout eastern and central Africa. We found that dietary grass fraction increased with body size for the majority of herbivore communities considered, especially when complete community data were available. However, the slope of this relationship varied, and rainfall seasonality and elephant presence were key drivers of the variation—grass dependence increased less strongly with body size where rainfall was more seasonal and where elephants were present. We found also that..., We quantified local grass dependence from a dataset of stable isotope data collected from across eastern and central Africa, Cerling et al. (2015). We identified which species were missing local data using a dataset of herbivore community composition, Rowan et al. (2020). We then computed regional species-level averages for those community members missing local diet data, also from the aforementioned stable isotope dataset. 
We extracted species-level body mass estimates from EltonTraits (Wilman et al. 2014).
We downloaded shapefiles for each community from the World Database on Protected Areas (WDPA). Using these shapefiles, we extracted environmental covariates for each herbivore community: we calculated mean annual rainfall, mean rainfall seasonality, mean annual temperature, and mean temperature seasonality for each community from climatic data layers downloaded from WorldClim 2.0 (Fick and Hijmans 2017); we extracted estimates of woody cover for each community from a data layer of ..., , This 'README_file_Herbivore community assembly.txt' file was generated on 2024-01-23 by JOEL O. ABRAHAM

GENERAL INFORMATION

1. Title of Dataset: Environmental context shapes the relationship between grass consumption and body size in African herbivore communities

2. Author Information
A. Principal Investigator Contact Information
Name: Joel O. Abraham
Institution: Princeton University
Email:

B. Associate or Co-investigator Contact Information
Name: J. Tyler Faith
Institution: University of Utah
Email:

3. Date of data collection (approximate): 2023-08-01 to 2024-01-13

4. Geographic location of data collection: eastern and central Africa; compiled from existing literature/data sources

5. Information about funding sources that supported the collection of the data:
Joel O. Abraham was supported by the NSF GRFP
J. Tyler Faith was supported by NSF grants CNH-1826666 and 2224318

SHARING/ACCESS INFORMATION

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