Jess (falconry) anklet worn by the bird, which is itself formed of another rectangular strip of leather, bound together at the ends by a grommet (usually of brass), prevented from slipping through the grommet by the knobbed end. Often, another slit is placed near the thin end of the jess cut about one inch long and running lengthwise, through which a special type of swivel is fitted, preventing the whole arrangement from twisting or tangling about itself or the bird when a leash is threaded through the other end. Their intent is more to prevent the risk of the bird deciding to
Falconry are kept for purposes of rehabilitation (for which a licence must still be held), and in such circumstances it may be possible for a competent falconer to teach a bird to hunt and kill wild quarry, as part of its regime of rehabilitation to good health and a fit state to be released into the wild. In New Zealand, falconry was formally legalised for one species only, the swamp/Australasian harrier ("Circus approximans") in 2011. This was only possible with over 25 years of effort from both Wingspan National Bird of Prey Centre and The Raptor Association of New Zealand (RANZ).