Abstract Wildebeest drownings produce dense bone deposits over large surface areas adjacent to lakes and rivers in the Serengenti ecosystem of East Africa. Drownings occur during the annual wildebeest migration when animals cross rivers and lakes on their way to wet season pastures. Drownings involve both small and large numbers of adult and newborn wildebeest and can occur in a single event or a sequence of small and large events during the wet season. Signature criteria from surface skeletal remains produced by modern drownings that may, as an integrated set, help to identify them in the fossil record include: (1) the predominance of adults from a single species and the variable representation of newborns and yearlings; (2) the presence of intact elements from all adult skeletal groups; (3) assemblages dominated by axial elements and long bones; and (4) negative correlations between the representation of long bones and their marrow wet weights; assemblages from large drowning events possess weak negative correlations while small events possess strong negative correlations. The application of these criteria requires a landscape sampling strategy, because the drowning event's signature can be spread out over hundreds or thousands of metres of river or lake front. Consequently, localized samples from a large drowning may be affected differently by carnivores, flowing water, trampling, weathering, and/or burial and not possess all of these signature criteria. Drownings represent important scavenging opportunities for a wide variety of consumers because of the number of carcasses they can produce. Their occurrence in rivers and lakes also gives them some seasonal and spatial predictability. Under these circumstances, it is possible that water-restricted early hominids may have gained relatively early access to large animal carcasses without recourse to hunting or confrontational scavenging. Early access to carcasses would have been facilitated by the simultaneous presence of many drowned individuals over a large area, because these conditions act to reduce inter- and intra-specific competition for carcass foods among consumers. Later access to carcasses could still have provided hominids with a wealth of nutritious long bone marrow and cranial contents.