What is the function of a swivel in falconry?

The function of a swivel in falconry is to prevent tangling of the leash and jess. When a bird is outside or in flight, its movements can cause the leash and jess (the straps attached to the bird's legs) to twist around each other. This twisting can lead to entanglement, which could pose a risk to the bird’s mobility and safety. The swivel allows for free movement and rotation, ensuring that the jess and leash remain untangled, thus enabling the raptor to move freely and safely while being tethered.

Other options relate to different equipment or functions that do not directly involve managing the leash and jess dynamics. For example, attaching bells or holding a perch in place involves separate aspects of falconry gear that do not address the tangle prevention function of the swivel.