Medieval Lore: The Curious Myth of the Origin Barnacle Geese

Ray Oaks, CC BY-SA 4.0 https://creativecommons.org/licenses/by-sa/4.0, via Wikimedia Commons

Myth

Barnacle geese are a migratory species of water bird that have a very weird myth of origin attached to them that was once widely believedDuring the medieval period there was a belief that barnacle geese were not hatched from eggs but actually grew on trees or spontaneously on pieces of driftwood that floated in the sea.  This strange myth was widespread at the time and believed by  many eminent people of the day.   In this work we will look briefly at the barnacle followed by a look at barnacle geese both of which are real creatures.  This will be followed by discussing some of these strange ideas before concluding with our views on them today.

Migration

During the months of October through to March, parts of the British Isles and certain parts of Europe played host to flocks of barnacle geese.  This puzzled medieval people as they seemed to arrive out of nowhere and leave in the same manner.  No one had seen their nests, or  their eggs, or their young and no one knew how, or where, they bred giving rise to speculation about their origin.  

Real Barnacles

A strange theory evolved that they actually grew from crustaceans called gooseneck barnacles (Lepas anatifera) that were found on pieces of driftwood around the sea shores.  Many people thought that a tuft of brown cirri that protruded from the capitulum of the crustacean looked very similar to the down found on unhatched goslings of other species. This similarity is not obvious to many other people but the barnacles were seen as the result of spontaneous generation from the driftwood which will be briefly discussed later.

Real Barnacle Geese

We know today that real barnacle goose (Branta leucopsis)  live and breed mainly on the three islands of Greenland, Svalbard and Novaya Zemlya in the oceans of the far north during the summer months.  After a long flight they would suddenly appear at British,  Irish and other European sites as fully grown adult geese.  People were puzzled because they had seen no signs of a nest, eggs or even goslings but still they would appear at certain times of the year with unerring regularity.   To solve this puzzle some very peculiar answers evolved. 

The Barnacle Goose Tree

One such answer was the barnacle goose tree.  According to this myth young barnacle goslings grew on branches of a tree that overhung water in a similar way to nuts, fruit or berries sometimes do.  On becoming ripe, or big enough they drop from the branch safely into the water and are able to swim and float immediately eventually growing to maturity.  Those that missed the water and fell on to the ground died.

Sir John Mandeville

In the 14th century the traveller and writer Sir John Mandeville wrote in The Travels of Sir John Mandeville, his travel journal,

“I told them of as great a marvel to them, that is amongst us, and that was of the Bernakes, (barnacle geese). For I told them that in our country were trees that bear a fruit that become birds flying, and those that fell in the water live, and they that fall on the earth die anon, and they be right good to man’s meat. And hereof had they as great marvel, that some of them trowed it were an impossible thing to be. (1)

This and similar strange answers  to the origin of the barnacle goose was widely accepted especially among the clergy of the day.  

Gerald of Wales

Another myth of origin of the barnacle goose tells how it was born from driftwood from the sea.  Gerald of Wales,  also known as, Bishop Giraldus Cambrensis, was  12th century Welsh bishop who published a book, Topographia Hiberniae  after the invasion of parts of Ireland by King John where he mentioned how Irish clergy ate the barnacle goose on fast days which surprised him, 

“Nature produces [Bernacae] against Nature in the most extraordinary way. They are like marsh geese but somewhat smaller. They are produced from fir timber tossed along the sea, and are at first like gum. Afterwards they hang down by their beaks as if they were a seaweed attached to the timber, and are surrounded by shells in order to grow more freely. Having thus in process of time been clothed with a strong coat of feathers, they either fall into the water or fly freely away into the air. They derived their food and growth from the sap of the wood or from the sea, by a secret and most wonderful process of alimentation. I have frequently seen, with my own eyes, more than a thousand of these small bodies of birds, hanging down on the sea-shore from one piece of timber, enclosed in their shells, and already formed. They do not breed and lay eggs like other birds, nor do they ever hatch any eggs, nor do they seem to build nests in any corner of the earth “ (2) 

His observation, although erroneous, gave the myth credence and it spread across Europe.   However he took a dim view of the clergy eating them on fasting days saying, 

“…Bishops and religious men (viri religiosi) in some parts of Ireland do not scruple to dine off these birds at the time of fasting, because they are not flesh nor born of flesh … But in so doing they are led into sin. For if anyone were to eat of the leg of our first parent (Adam) although he was not born of flesh, that person could not be adjudged innocent of eating meat.” (3)

Sir E. Ray Lankester  

In 1915, Sir E. Ray Lankester, a British zoologist in his book, “Diversions of a Naturalist,” speculated on why this myth may have been popular with medieval clergy especially in Britain and France.   He picked up on the practice of the clergy eating them on fasting days for the popularity of the myth among them.  To make it an acceptable fasting meal they declared the barnacle goose to be more fish than a fowl and as such acceptable to be consumed on fasting days. 

Pope Innocent III was concerned enough about this practice to prohibit the eating of Geese during Lent at the Fourth Council of the Lateran in 1215.  Nevertheless he still seemed to accept the myth of their reproduction but pointed out that they lived and fed in a similar way to ducks and concluded that their nature was the same as other birds.

A Shift in Thinking

The bizarre myth of the reproduction of barnacle geese looks a typical example of superstition, ignorance and imagination run wild, but is it?  In the Middle Ages the Church drew moral lessons from nature but a shift in thinking appeared that saw nature as being worthy of studying in its own right.  This is where the myth of the origin of the barnacle goose comes in.

Spontaneous Generation 

A theological idea became  tangled  up in the debate of whether it was fowl or fish  which centered around the idea of spontaneous generation.  it was argued that gooseneck barnacles were spontaneously generated from the rotting driftwood. There was a common belief going right back to Aristotle that if the right conditions were present then the spontaneous generation of living organisms could and did occur arising from inorganic or nonliving material.   Despite the remarkable nature of the supposed origin of these lifeforms they had an ordinary lifestyle of sorts and manifest in a predictable way without divine intervention.  It was the assumption that they lacked parents which led to all sorts of theological arguments among Christians about Immaculate Conception and the Virgin Birth (which are not the same as each other) and cannot be fully dealt with here.

Frederick II of Hohenstaufen

Frederick II of Hohenstaufen, holy Roman Emperor and King of Sicily and Jerusalem about 200 years after Gerald of Wales was rather more doubting in his assessment of the spontaneous generation of the barnacle goose.  He wrote  saying, 

“There is also a small species known as the barnacle goose, arrayed in motley plumage …, of whose nesting haunts we have no certain knowledge. There is, however, a curious popular tradition that they spring from dead trees. It is said that in the far north old ships are to be found in whose rotting hulls a worm is born that develops into the barnacle goose. This goose hangs from the dead wood by its beak until it is old and strong enough to fly. We have made prolonged research into the origin and truth of this legend and even sent special envoys to the North with orders to bring back specimens of those mythical timbers for our inspection. When we examined them we did observe shell-like formations clinging to the rotten wood, but these bore no resemblance to any avian body. We therefore doubt the truth of this legend in the absence of corroborating evidence. In our opinion this superstition arose from the fact that barnacle geese breed in such remote latitudes that men, in ignorance of their real nesting place, invented this explanation.” (4)

It had previously been thought that the Barnacle Goose migrated  to the British Isles via Scandinavia and the strange transformation occurred in the Norse countries.  He was at least right that they did breed in the remote regions of the north that were largely still unknown and not generated from rotting wood.

Morals from Nature

It has long been a practice for Christians to draw moral points from the natural world to reinforce theological ideas. This began in the 2nd century  with the Physiologus where nature was seen as the second book of God, until the early 17th century when natural history became better studied and understood.  However, as science progressed people became more skeptical about such ideas.

Albert the Great

Around the middle of the 14th century Albert the Great came up with a simple way of testing the spontaneous generation  theory by breeding them and noting that they did in fact lay eggs calling the myth, 

“altogether absurd as I and many of my friends have seen them pair and lay eggs and hatch chicks”. (5)

Despite this there were still those as late as the 16th century such as  Joseph Justus Scaliger who insisted that the spontaneous generation theory was right claiming to have witnessed it. 

Belief in the myth, either through self-interest and wanting to dine on meat on fast days, or ignorance, still lingered for a while.  Finally, science and reason prevailed and finally managed to explain how barnacle geese really reproduced.  It is very easy for us today to look back at certain erroneous absurd beliefs that were held to be true in the past but which were eventually proved false.   This itself highlights the frailty of human reason and we cannot help but wonder what people living in future time will make of some of our own beliefs we hold dear in our own times.  Let us hope they will not judge us too harshly.

© 25/03/2021 zteve t evans

References, Attributions and Further Reading

Copyright March 25th, 2021 zteve t evans

6 thoughts on “Medieval Lore: The Curious Myth of the Origin Barnacle Geese

  1. A little knowledge is a dangerous thing, right enough! Thanks for this intriguing and well-researched post, Zsteve. Makes me wonder how many more … ? Cheers Meg

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