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
The Sibley Guide to Bird Life & Behavior The Sibley Guide to Bird Life & Behavior The Sibley Guide to Bird Life & Behavior is a book by David Allen Sibley that shows readers "how birds live and what they do." It is different from most field-identification guides that birdwatchers carry around; rather than help identify birds, it helps watchers gain a deeper understanding of the birds they have already identified. Instead of concentrating on individual species, the book summarizes information for families of birds, presenting "broad patterns" to help readers interpret what they see. The guide includes nearly 800 of Sibley's paintings. The book was first published