Study
Why Lions Form Groups: Food is Not Enough
Packer, Craig; Scheel, David; Pusey, Anne E.
The American Naturalist, 1990
Foraging success, prey intake per lion and group size were measured across Serengeti prides over years, testing directly whether cooperative hunting explains sociality — the standard assumption — by asking whether lions in groups actually eat better than lions alone.
- Studied in
- Panthera leo
- Sample size
- Serengeti prides followed across years of continuous observation
Per-capita food intake does not increase with group size across most of the range of group sizes; lionesses in medium-sized groups often do worse than singletons or pairs. Group size instead tracks the ability to defend a territory and to protect cubs against infanticidal males. Female group size is best explained by competition with other prides.
What it means
The authors' reading, and ours. Where they differ, that difference is the point.
How the authors put it
Cooperative hunting does not explain lion sociality. Group living is maintained by territory defence and cub protection rather than by feeding benefits.
How NatureHQ reads it
This is the landmark that reorganised the subject, and it did so by testing the obvious explanation and finding it false. Everybody knew lions are social because hunting together works better; measured over years, it does not — a lioness in a group frequently eats less than one alone. What group living actually buys is the ability to hold a territory against neighbouring prides and to defend cubs against males, which is a very different account of what a pride is *for*. It also explains an otherwise puzzling observation: lions hunt cooperatively rather badly, with individuals frequently holding back.
- One ecosystem, though a very well characterised one over decades.
- Per-capita intake is difficult to measure precisely in the field and rests on observed kills and estimated shares.
- Prey availability in the Serengeti is unusually high, which may weaken feeding benefits relative to other systems.
Testing the explanation everybody already believed
Do lions live in groups because hunting together works better?
What this study is used for on NatureHQ
One study can inform several subjects. Here is everywhere this one is cited.
Published by: University press journalsPublished in a university press journal.
This reference was resolved automatically against Crossref on 2026-08-11.
NatureHQ summarises research in its own words and does not reproduce published text. Reviewed 2026-08-11.