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 in the early 20th century. Col R. Luff Meredith is recognized as the father of North American falconry. Throughout the 20th century, modern veterinary practices and the advent of radio telemetry (transmitters attached to free-flying birds) increased the average lifespan of falconry birds and allowed falconers to pursue quarry and styles of flight that had previously resulted in the loss of their hawk or falcon. The often-quoted "Book of St Albans" or "Boke of St Albans", first printed in 1486, often attributed to Dame Julia Berners, provides this hierarchy of hawks and the social ranks for which each bird was