Stable isotope analysis — a technique that examines the ratios of specific chemical isotopes in bone collagen, which reflect the composition of the diet — has been applied to Mesolithic skeletons across Britain and Europe and reveals a consistent pattern: high protein intake, primarily from terrestrial mammals and freshwater fish.

At Gough’s Cave specifically, the archaeological deposits contain the bones of red deer, wild horse, giant deer (also called Irish elk, though it was found across Europe), and various smaller mammals.

Freshwater fish were likely important, though fish bones are fragile and may not preserve as well as mammal bones.

Plant foods — nuts, berries, roots, seeds — would have been seasonally important, particularly in summer and autumn, though plant remains are often poorly preserved in archaeological sites.

The Mesolithic world of Britain was not the impoverished, hand-to-mouth existence that some earlier accounts implied.