Predator birds such as falcons and hawks, used in the so-called sport of falconry, have restraints called jesses that are used until the bird is sent in to hunt.
An Anklet is attached around the bird’s leg. A jesse is the long strip of leather that attaches through an eyelet in the anklet. The jesse has a hole close to the end to which a strong piece of material such as a leash is attached for tethering the bird.
The legs of predatory birds are heavy and muscular. Using their feet, they are able to capture and carry prey.
A parrot’s legs are very different. They are very slim and used for climbing and hopping about. Using restraints on these delicate legs can have serious consequences. Their legs can be broken or even amputated if they try to fly off suddenly.
A tethered parrot can also wind up a a meal for a predator because there is no way to escape.
If you want to give your parrot some exercise outdoors, train him/her with a harness. There are a number to choose from which will suit your bird. Or place the parrot in a secure cage outdoors, making sure that no predators can disturb or harm your bird. NEVER leave your bird unattended outside.