The wishbone or furcula is the fusion of a bird's two collarbones (clavicles) into a single structure. The furcula is attached to the shoulders, and may also be fused to the sternum (breastbone) or simply attached with a strong, stiff tendon. These connections protect the chest cavity during flight, helping a bird keep its body shape and internal structure intact even under great stress. This ensures that the motions and muscular contractions of flight do not break a bird's ribs or collapse its lungs.
What Is a Wishbone?
The wishbone is a central, V-shaped bone in a bird's chest that is part of the pectoral girdle and helps stabilize the chest cavity for flight. Wishbones are less commonly known as furculas.
The wishbone may be a Y, V or U shape, and the overall shape, size, curvature, flexibility and strength of the bone varies between bird species. In larger birds, such as some falcons and cranes, the arms of the furcula are often hollow to lighten the bird's weight. The wishbone is flexible, and can expand up to 50 percent larger than its resting position in some species, depending on their overall flight style.
The furcula helps stabilize a bird's body during flight, particularly on the upstroke of the wings when more lift is generated and the thoracic cavity is under the greatest stress. It is also believed that the furcula may serve a secondary function for bird respiration, helping pump air through the bird's air sacs for more efficient breathing. Ornithologists have had difficulty determining the exact purpose of the furcula, since it appears to have variable effectiveness in different birds, and some birds lack this structure altogether. Some owls, toucans, parrots, barbets and turacos have no distinct furcula, yet have no trouble breathing or flying without its assistance.
The furcula is also found in a number of dinosaurs and provides another link in the evolutionary theory connecting dinosaur ancestors to modern birds. Dinosaurs with distinct furculas or similar wishbone-like structures include many theropods such as the allosaurus, velociraptor and tyrannosaurus rex. The immediate predecessor to modern bird ancestors, archaeopteryx, also had a prominent furcula.
Wishbones in Human Culture
The wishbone has many unique meanings and ceremonial purposes in human culture and history, including...
- In medieval Europe, it was believed that the wishbone of a goose eaten for the Feast of St. Martin (a harvest celebration traditionally held on November 11) could be closely examined to foretell the weather. This was often used specifically to predict how harsh the coming winter would be, as well as whether the season would be dry or wet.
- The ancient Etruscans of Italy used the furculas and other parts of chickens, as well as the actions of the birds themselves, to predict the future. A dried furcula would be stroked and wished upon.
- Prussian and Celtic Teutonic armies often used the furculas of geese to study the weather, and would plan wars and other military campaigns based on their studies.
- Conquering Romans spread the custom of lucky wishbones throughout Europe and into England, and eventually the idea of breaking a furcula for a wish spread to the English colonies in North America. Since the early 1600s, the custom has been more closely associated with turkeys rather than chickens, but may be practiced with any wishbone. Two people will hold the opposite ends of the furcula and pull, and the superstition is that the person who has the larger piece of the broken bone has had a "lucky break" will have their wish granted. If wishes are not made, the larger piece of the broken bone may also be associated with general good fortune or good luck.
- Wishbone necklaces are considered a lucky charm in many cultures, and if real furculas are used to create such a necklace, adding more wishbones is said to strengthen the luck of the necklace. The furcula shape is widely available as a pendant, charm, earrings, rings, cufflinks and other types of jewelry as well.
Also Known As
Furcula, Merrythought Bone, Merry-Thought Bone