Mystery of 8,000 Frog Bones in One English Ditch Solved: Birds of Prey Feasted About 1,700 Years Ago, Study Finds
New research has solved the mystery of some 8,000 amphibian bones found in a single ditch at the Bar Hill site in Cambridgeshire, England: birds of prey such as short-eared owls feasted on the frogs during a short, intensive predation event about 1,700 years ago. The findings were reported on November 13.
The bones were unearthed between 2016 and 2018. Between 2016 and 2022, archaeologists excavating along a planned stretch of England's A14 highway uncovered more than 280,000 artifacts spanning roughly 12,000 years, including a Roman amulet carved to resemble the mythical Gorgon Medusa, the earliest physical evidence of beer production in Britain, and an Iron Age comb crafted from a human skull.
The majority of the bones belonged to frogs and toads, specifically common frogs, but shrews, voles, and mice were also present in the assemblage. The remains represented no fewer than 469 individual animals.
Based on an analysis of amphibian arm bones, researchers led by Vicki Ewens, a senior zooarchaeologist at the Museum of London Archaeology (MOLA), and Paul Clarkson, an archaeologist at Bournemouth University, concluded that most of the frogs died young, eaten by birds of prey such as short-eared owls and hen harriers in the second or third century C.E., during Britain's Roman era.
As the authors write in the journal Environmental Archaeology, water levels in the Fens, the marshy wetland that houses the gully, retreated during the Roman period, enabling frogs in drying-out ponds to reproduce at a faster rate.
MOLA first announced the find in 2022. Four years later, the new analysis offers an explanation for how so many frog remains ended up concentrated in one ditch.
Source: Environmental Archaeology
Published by GSM · USA (original Chinese edition)
Photo: 图：一只普通林蛙（Rana temporaria）的侧面，Bar Hill 沟中出土的两栖动物骨骼多数属于这一物种。来源：Holger Krisp, CC BY 3.0，维基共享资源。 / Photo: A common frog (Rana temporaria) in profile; most of the amphibian bones from the Bar Hill ditch belonged to this species. Credit: Holger Krisp, CC BY 3.0, via Wikimedia Commons.
