Jess (falconry) the bird, but the width is proportional to leg-length. Traditional jesses are made from a single length of leather, and slits are placed strategically along the jess to allow it to be looped through itself and around the ankle of the bird so that it fits comfortably but securely about and just above what would be the bird's ankle. With Aylmeri jesses, as created by Major Guy Aylmeri, the end of the jess is instead looped through itself repeatedly to form a "button", or knob at one end. The thin, pliable end of the jess is then threaded through an
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).