Data from: Mammalian herbivory indirectly shapes savanna arthropod communities, but only at very low or high levels

Savanna ecosystems support unique biodiversity and provide livelihoods for millions of people. Yet, wild herbivores are in decline due to poaching and land-use change while livestock numbers are increasing. These changes in density and composition alter savanna vegetation. There are likely indirect cascading effects of altered vegetation on savanna arthropods, but our understanding is limited despite their pivotal role in ecosystem functioning. We evaluate how differences in mammalian herbivory affect terrestrial arthropods in a semiarid Kenyan savanna. We sampled ground-active arthropods (focusing on ants) in six herbivory treatments ranging from high-intensity herbivory to complete exclusion of large herbivores. Ant abundance and richness were not affected by herbivory treatments, but the community composition of ants and arthropods differed at extremely high and low levels of herbivory due to indirect impacts on vegetation. The dataset consists of the raw ant data, the raw arthropod data and the raw vegetation data. The ant data consist of the plot ID, pitfall ID, treatment category and the ant morphospecies with the respecitve count numbers per pitfall trap. The raw arthropod data consist of the plot ID, the treatment category and the arthropods at order level, this data has been pooled togehter across all pitfall traps from the same plot. The vegetation data consist of plot ID, treatment category, and the vegetation parameters grass richness, forb richness, mean hight of standing vegetation, mean percentage of bare ground cover, and tree density per hectare. # Data from: Mammalian herbivory indirectly shapes savanna arthropod communities, but only at very low or high levels Dataset DOI: [10.5061/dryad.kwh70rzk2](doi.org) ## Description of the data and file structure The ant and arthropod data were collected by pitfall traps. Fifteen pitfall traps were placed in three transects with ten meters distance between traps. The traps were filled with propylene-glycol (50%) and left for three days, until they were retrieved and samples identified under a microscope. All arthropods were identified to order level, ants were identified to genus level, and then assigned to morphospecies. The vegetation data were collected on 50 x 50 meter sampling plots. Grass and forb richness and percentage of bare ground were assessed on two parallel 50-m transects, using a 1 m^2^ quadrat placed every 5 m along the two transects, i.e., 20 vegetation measurements per variable plot. All trees in each plot with a diameter of 5 cm or greater (measured at a height of 50 cm from the ground) were counted to estimate tree density (ha). We measured herbaceous vegetation height using a Disc Pasture Meter with a disc diameter of 45.5cm on 100 points equally distributed across each plot and used the mean of these 100 measurements for analysis. ### Files and variables #### File: Mammalian_herbivory_ant_data_2025.csv ##### Variables * Plot_ID: Unique ID of each of the 20 sampling plots (1-20) * Pitfall_ID: ID of each of the 15 pitfall traps from the three transects (A1, A2, A3, A4, A5, B1,...B5, C1,....,C5) * Treatment: ID of each of the six herbivory treatments (A - F), ranking from high intensity herbivory (A) over intermediate levels of herbivory (B-E) to mammalian herbivory suppression (F) * Cardiocondyla_1 to Tetraponera_1 : Counts of ants at morphospecies level #### File: Mammalian_herbivory_arthropod_data_2025.csv ##### Variables * Plot_ID: Unique ID of each of the 20 sampling plots (1-20) * Treatment: ID of each of the six herbivory treatments (A - F), ranking from high intensity herbivory (A) over intermediate levels of herbivory (B-E) to mammalian herbivory suppression (F) * Coleoptera to Hymenoptera: Counts of arthropods at order level #### File: Mammalian_herbivory_vegetation_data_2025.csv ##### Variables * Plot_ID: Unique ID of each of the 20 sampling plots (1-20) * Treatment: ID of each of the six herbivory treatments (A - F), ranking from high intensity herbivory (A) over intermediate levels of herbivory (B-E) to mammalian herbivory suppression (F) * grass_richness: number of different grass species found in the 20 sampling quadrats * forb_richness: number of different forb species found in the 20 sampling quadrats * mean_height_of_standing_vegetation: mean value of the 100 DPM measurements (cm) * mean_bare_soil: mean value of percentage of bare ground cover from the 20 sampling quadrats * tree_density: number of trees per hectare ## Code/software All files are in csv. format and can be opened with Excel, R and other software ## Access information Other publicly accessible locations of the data: * n/a Data was derived from the following sources: * n/a