The leather straps placed on the birds legs.
Leather straps attached to the legs (tarsi) of a trained raptor. AYLMERI JESS - A leather bracelet with grommet and jess.
Strips of light hut very tough leather, some 6 to 8 in. long, which always remain on a hawk's legs; one on each leg.
Jesses are thin straps, traditionally made from leather, used to tether a hawk or falcon in falconry. The correct singular is jess.