The Geese That Grew on Trees
Medieval Europeans believed that some geese weren't born from eggs at all, but grew on driftwood like fruit, inside seashells.
What was reported
No one in medieval Europe had ever seen barnacle geese nest. They arrived every autumn and disappeared every spring. An explanation spread: they grew from goose barnacles, shellfish that cling to driftwood, whose feathery feeding arms looked like tiny birds inside their shells.
In 1188, Gerald of Wales wrote that he had seen more than a thousand of these tiny birds hanging from a piece of timber on the Irish shore. Since the birds weren't born of flesh, some argued, they could be eaten on fasting days when meat was forbidden. In 1215, Pope Innocent III banned the practice.
Explanations offered
Barnacle geese breed in the far Arctic, in Greenland, Svalbard and Russia, where medieval Europeans never went. The myth lasted until the 1600s and is why the bird and the shellfish share a name.
- When
- Told from the 1100s
- Where
- The west coast of Ireland
- Witnesses
- Medieval writers, including Gerald of Wales
- Status
- Explained
Famous cases are real, widely reported events. Each file sets out what witnesses said and the explanations that have been offered, without taking a side.
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