The Barnacle goose (or Brant goose) is a mythical tree believed in the Middle Ages to have barnacles that opened to reveal baby geese. In the medieval imagination, the coasts of Scotland and Ireland harbored a marvel not found on any mainland—trees bearing geese as fruit.
According to travelers and clerics, the barnacle goose (Branta leucopsis), which was never seen nesting in Europe (because it breeds in the Arctic), did not hatch from eggs. Instead, these birds were believed to grow from driftwood or trees near the sea, hanging like fruit in clusters or encased within barnacle-like shells. Some accounts described them hanging from trees by their beaks, resembling bizarre fruit with feathered insides. Others claimed they emerged from foam or seaweed, like pearls of the ocean.
In mythological story[]
Act 1[]
Brother Cillian, a young and earnest monk, lives in a remote abbey overlooking the stormy Irish Sea. The abbey’s monks hold a curious tradition: during Lent, they feast on barnacle geese, which are considered “fish” because they supposedly grow not from eggs, but from barnacles attached to driftwood and “goose trees” that wash ashore. This belief is a sacred part of their faith and practice.
Cillian is skeptical yet respectful of the tradition. When a violent storm brings a massive log coated in strange barnacles to the beach near the abbey, the monks gather excitedly. From the barnacles, tiny geese emerge, covered in wet feathers and blinking in the salty air. Cillian witnesses the miracle firsthand and starts documenting it meticulously, his heart torn between faith and doubt.
At the same time, Aoife, a curious scholar and traveler from the mainland, arrives at the abbey seeking knowledge of the natural world beyond accepted church teachings. She challenges Cillian’s beliefs and urges him to question the nature of miracles and myths.
Act 2[]
Motivated by Aoife’s questions and his own growing doubts, Cillian leaves the abbey on a pilgrimage to discover the true origins of the barnacle goose. He travels to the distant lands of Tartary and the northern coasts where the birds are said to breed but remain unseen by most Europeans.
Along the journey, Cillian and Aoife encounter to fishermen who swear the geese are born from driftwood but warn of a dark curse on the “goose trees.” Druids and nature priests who speak of a sacred bond between sea, sky, and earth in a mysterious hermit who claims the barnacle goose is a guardian spirit, tied to the land’s balance.
Cillian learns of an ancient legend: that the geese represent souls trapped between worlds—neither fully animal nor plant, flesh nor spirit—bound to the sea by a forgotten curse.
Act 3[]
Cillian returns to the abbey carrying knowledge that shakes the foundation of his faith. The “miracle” of the barnacle goose is revealed as a natural, if strange, phenomenon — migratory birds hatching far from human eyes, misunderstood and mythologized.
Yet, the local people cling to the myth because it sustains their sense of wonder and connection to the divine. Cillian faces a painful choice to reveal the truth and risk shattering belief and tradition or to protect the myth, preserving hope and sacred mystery.
In the final confrontation, a fierce storm threatens the abbey and the coastal village. Cillian prays not just for survival but for a new understanding—one that embraces both faith and reason.
Epilogue[]
Years later, Cillian’s writings survive, blending observation with myth, inviting future generations to question and believe in their own ways. The barnacle goose remains a symbol of the delicate dance between nature and legend, reminding all who hear its story that some truths are woven from both fact and wonder.