Lion pride size versus feeding group size
Data files
Sep 08, 2025 version files 22.82 KB
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Feeding_groups_vs_pride_size_Serengeti.txt
18.68 KB
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README.md
4.14 KB
Abstract
The attached dataset provides a sampled distribution of 3230 feeding groups of adult female lions in relation to size of the pride that those females belonged to in Serengeti National park, Tanzania. Ecological theory suggests that large social groups of carnivores should have reduced foraging efficiency because they encounter prey no more frequently than solitary hunters, but the entire group must share any prey they encounter. We developed behaviorally-based foraging models to show that fragmentation of large social groups into smaller hunting subgroups or mutual cooperation during hunting are both plausible hypothetical mechanisms capable of sustaining larger lion prides. The attached dataset from the Serengeti ecosystem demonstrates that lion prides typically fragment into small hunting groups that are well approximated by an exponential distribution of group sizes typical of fission-fusion social systems. A model linking fission-fusion group dynamics with predator-prey interaction predicts both the surprising degree of population stability of the Serengeti lions as well as the long-term persistence of large prides. There is little evidence, however, that Serengeti lions cooperate during hunting except when they hunt Cape buffalo, so fission-fusion is apparently the dominant stabilizing process in Serengeti.
Description of the data and file structure
Data for the paper are provided in the attached data file: Feeding_groups_vs_pride_size_Serengeti.txt. This is an exceptionally simple dataset, aggregating data from Serengeti National Park on the number of adult females found in lion feeding groups on an ad hoc basis over the course of a multi-decadal field study led by Prof. Craig Packer at the University of Minnesota. Basic procedures contributing to the dataset can be found in C. Packer (2023), The Lion, Princeton University Press. There are 3560 observations in the dataset, with each observation on a separate line in the file. The variable 'Pride' refers to the number of adult females in the pride to which the feeding group belongs. The variable 'Females' refers to the number of females in the feeding group that was observed. In each case, the variables represent integer count data, with no SI units.
Code/Software
6 files are archived on Zenodo (10.5281/zenodo.15620828) that replicate the 6 figures shown in the publication. Figures 1 to 4 are written as R code (version 4.3.1). They all use the following data file stored on DRYAD: Feeding_groups_vs_pride_size_Serengeti.txt. No additional R packages are needed for any of the analyses or plots.
Fig. 1 - Plot feeding group distribution vs Serengeti pride size.txt uses histograms to plot the observed frequency of feeding group sizes of Serengeti female lions in prides of different sizes.
Fig. 2 - Fit feeding group distribution to exponential model.txt calculates the best fit loglinear relationship between frequency of feeding groups (from Fig. 1) and log(feeding group size) for each size of pride.
Fig. 3 mean size of feeding groups vs pride size.txt plots the mean size of feeding groups observed in relation to pride size. Model evaluation is used to compare 3 potential relationships between these variables: no relationship, a linear relationship, and an asymptotic exponential relationship between variables. The latter relationship provided the most parsimonious fit to the data and is displayed in the figure.
Fig. 4 - Plot lion intake vs prey density by pride size.txt plots the estimated rate of food intake by Serengeti lions that apply 4 different foraging strategies (A: feed as an entire pride uncooperatively, B: feed as an entire pride cooperatively, C: fragment into uncooperative groups according to the distribution of feeding groups shown in Fig. 1, and D: fragment into cooperative groups according to the distribution of feeding groups shown in Fig. 1.
Fig. 5 and Fig. 6 are written as MATLAB code (version R2018b). Neither figure requires additional MATLAB packages to run.
Fig_5_Stability_as_function_of_lion_group_size.m: MATLAB code to run simulation model that evaluates the the stability and persistence due to predator-prey interactions by a lion population with a baseline probability of capture success = 0.294 that (A) always forages as an uncooperative pride, (B) as a cooperative pride, (C) as uncooperative hunters whose feeding groups are distributed according to the observed frequency distribution for Serengeti, and (D) as cooperative hunters whose feeding groups are distributed according to the observed distribution for Serengeti shown in Fig. 1. Other parameters as shown in Table 1 of the main text. Each model scenario has its own section of annotated code.
Fig_6_Stability_as_function_of_lion_group_size.m: MATLAB code to run simulation model that evaluates the the stability and persistence due to predator-prey interactions by a lion population with a baseline probability of capture success = 0.150 that (A) always forages as an uncooperative pride, (B) as a cooperative pride, (C) as uncooperative hunters whose feeding groups are distributed according to the observed frequency distribution for Serengeti, and (D) as cooperative hunters whose feeding groups are distributed according to the observed distribution for Serengeti shown in Fig. 1. Other parameters as shown in Table 1 in the main text. Each model scenario has its own section of annotated code.
Lion social groups were sampled by vehicle every day by traversing the Serengeti National Park and from VHS radio-collar signals. If the group was feeding, the number of adult females in the group was noted, as well as the total number of adult females in the pride that the feeding group belonged to.