Training raptors (birds of prey) is a complex undertaking. Books containing hundreds of pages of information and advice by experienced falconers are still rudimentary at best. Many important details vary between individual raptors, species of raptors and between places and times. Unfortunately, without mentoring by an experienced falconer, raptors may be illegally taken and kept, and can be harmed by uneducated pseudo-falconers. Rather than attempt to train a raptor using only internet resources and books, it is wise to find experienced falconers and volunteer or apprentice with them. In point of fact, the keeping and training of any raptor is strictly and tightly regulated by U.S. state and federal laws. Anyone in the USA who is interested in flying raptors must seek out a state and federally licensed falconer to sponsor them through an apprenticeship period lasting two years at a minimum, and often considerably longer.
There are two styles of jesses: traditional, which is a single strap specially knotted onto the bird; and Aylmeri, a two part restraint featuring an anklet that is grommeted on, and a removable jess strap. Some Aylmeri jess straps have dental rubber bands on them to make it more difficult for the bird to pull out the jess, but they are still removable if the bird gets caught up outdoors. A good reference on these jesses is "Care And Management of Captive Raptors" by Lori Arent & Mark Martell, published by the University of Minnesota: this guide is very popular with zoos and wildlife centers, though it is not a traditional falconry book.
The singular of "jesses" is correctly "jess", but one jess is often mistakenly called a "jessie", by wrong back-formation from "jesses" treated as "jessies", which would be pronounced the same.
Nylon Aylmeri jesses have recently grown in popularity. Thinner, lighter, and stronger, they do not rot or need oiling to stay supple. The anklets are grommetted on, like their leather counterparts, but instead of a folded button keeping the straps from falling through the anklets, a knot is used. The end of the knot is melted with a cigarette lighter to keep it from fraying. In order to form the loops the swivel or clips will attach to, a nylon parachute cord is hollowed out, threaded up through itself using an awl, and knotted.
The swivel is to prevent tangling and twisting of the leash or tether when the bird is active but not hunting. The swivel consists of two parts that twist freely, each with a metal hoop on the end. The swivel may be traditional, or modified. The modified swivel has much larger metal hoops than the traditional. While swivels have been made of cloth or other materials in the past, most modern falconers use metal swivels.
When using Aylmeri jesses, there are usually two sets of straps: the mews straps, for manning and tethering the bird, and flying straps. The flying straps are lighter and smaller for hunting; the mews straps are heavy and less likely to break with stress.
Most importantly, hunting/flying jesses do not have the slit which can often get caught on a branch or bush, leaving the bird hanging too high up in the tree to be retrieved. Since using mews jesses in the field is dangerous to the bird, educated falconers no longer risk them. Instead, they are changed out before the bird is released to fly free, and the mews jesses returned into the grommets after the free-flight is over and the bird is safely in hand.
Jesses and anklets need to be replaced periodically, and checked for fit if they are causing injury.
A weighing scale is used to weigh the bird and its food. The scale must be reliable. This is especially important when dealing with small birds, as they may be endangered by even small weight differences when at flying weight. The successful hunting weight of the bird may vary, usually increasing as the bird is flown and develops more muscle (which weighs more than fat), but there is a relatively narrow range which the falconer seeks. Below that weight, the bird will be unnecessarily (and perhaps even dangerously) low and weak. Above that range of weight, the bird will be unresponsive in the field, lacking in motivation to hunt or return to the falconer in timely fashion.
Gauntlets or gloves are used by the falconer to turn the arm into a suitable perching surface. Falconry gloves may only cover the fist and wrist, while gauntlets for larger species extend to the elbow. An eagle glove may cover the entire arm and a portion of the chest, or it may be a heavy sheath worn over a standard hawking glove. The glove will have to be replaced with wear.
A creance is a long light line which is tied to the swivel or jesses. This is used only when training the bird to fly between a perch and the fist, as an assurance that the bird will not be lost in these early stages. The end away from the bird is most often wound around the spindle like a kite string; the creance can be wound or unwound with a single hand. This provides a means of storing the creance, and also provides a drag weight if the bird decides to fly off.
In the UK the only law concerned requires the bird to be able to spread its wings in all directions, however in practice a much greater space is needed to avoid conditions such as bumblefoot and depression. This lack of laws in the UK is the source of much concern among raptor keepers.
In all cases, a bird's diet is carefully measured to control its weight. Weight determines how hungry the bird is and how lazy it will act. A bird that is "fat," or has a higher weight, will be more likely to fly away or not hunt. A bird that is somewhat underweight will act aggressively, and a bird that is severely underweight will have health problems.
Birds that are in adult plumage at the time of trapping are called haggards and are no longer commonly used in falconry. The reason for this is twofold: first, birds that have matured in the wild are considerably harder to train for return (when released for hunting haggards have a tendency to go off hunting on their own and are easily lost); second, the capture of an adult bird removes a breeding age bird from the local pool of viable adults.
Taking a bird from the wild is illegal in the UK, as is releasing a captive bred bird.
Today experienced falconers know how to rear an imprint so that it has few or none of these undesirable behaviors, but it is time-consuming and requires unswerving dedication for a period of about three months. During that time, the eyass is not allowed to ever become truly hungry, and in nearly constant company and visual range of human beings, so that the arrival of food is not specifically associated with the arrival of humans. This bird is still very much imprinted on humans, but not food-imprinted, so the human is not considered something to be screamed at or attacked when hungry. In order to further assure that such correlations are not made, when it becomes ambulatory, some will take the bird to a separate room/area and allow it to "find" a plate of food, rather than having that food delivered to its face for it, as a parent bird would do. Finally, the young eyass is allowed to wander about at Tame Hack and enjoy more autonomy than would be possible with a chamber or parent-reared bird (owing to that the bird's affinity towards humans will keep it relatively close by, an affinity lacking in the chamber/parent reared eyass.) This provides the imprint eyass with an opportunity to learn to use its wings and develop musculature as well as the ability to fly in adverse conditions -- advantages that the chamber-raised bird does not have.
In the United States, the law requires that all hybrid raptors must be either imprinted or sterilized before they can be free-flown.
The training of the passage, the captive bred juvenile and the haggard bird are the same; the eyass needs a different approach, mostly conditioning the food-provider image away from that of the falconer and towards appropriate prey items and/or the lure. Also the training of falcons from the point of creance training is different from the training of the short-winged and broad-winged hawks ( redtails, Harris' Hawks, goshawks, etc.) because of the importance of the lure.
The training of hawks is not as difficult nor as mystical as some books say. It is a mutual bond based on respect, forged in food, patience and trust. One must never hit nor starve their hawk in their attempt to achieve this delicate bond. To do either shows that you do not possess the respect that your bird demands. A hawk cannot be dominated into compliance by starvation: this approach is simply heavy handed and cruel.
The passage or haggard bird will be fearful; this fear must be overcome to achieve trust. Once the new hawk is jessed and tethered to the glove, she should be offered small pieces of food. Most likely her hunger will not be great enough to overcome her fear of man at first, in this case she should be hooded up or placed within a darkened mew, tethered to her perch for one night. A hooded hawk or one in the dark can be offered water during this time by means of a squirt or misting bottle, and as the liquid collects on her beak she will drink it. The next day, take her up on the fist and again gently offer her small, bright red tidbits of meat with your fingertips. If she bites at your fingers, use blunt nosed tongs to hold the meat to her face. If she still does not eat, repeat the process the next day. Within one to perhaps three days she will come around - do not worry unless she does not eat within five days for a large hawk (700g+). Smaller hawks and falcons need to eat within one to two days from capture. Consult a vet at this point as the bird may be ill.
A trick that works well for getting a recalcitrant hawk to eat is to wait for her mouth to be open (most fearful hawks "gape", that is, hold their mouths open in threat) and then pop a small piece of meat into her mouth with the fingers or tongs. Mist a fine mist of water onto her beak and she will swallow. The taste of the meat will trigger a feeding response in her.
Once the hawk does snap at the meat and swallow, allow her to eat the thumbnail sized piece. Offer her another piece, and see if she refocuses her eyes from your face to the meat when she does. At this moment you will see her desire for the food begin to override her fear of man. If she becomes full or begins refusing the food, put her away and begin later. If she is still hungry and eager to participate, allow her to eat a few more pieces, and watch for her head to start reaching forward in anticipation of the food. Now you can begin to move the tidbits down a bit lower down her body, ever coming closer to your glove. Repeat this process of offering a tidbit, her eating it, and you lowering the height of the tidbit until she is eagerly snapping them up from the level of her own feet on the glove.
Begin putting tidbits on the glove only and cease finger or tongs feeding at this point. The hawk should at this point (please be sure she is still tethered to either the glove or her perch!) allow you to 'wipe' her off onto the back of a chair, her perch, or any other similar stationary object. Do this, and place a piece of meat onto your glove. Offer this to her at the level of her beak. She will most likely hesitate for a moment, pause, and then eat the meat like you have conditioned her to do. Repeat the process of offering a tidbit and lowering the glove until she is standing on the perch and feeding from the glove at the height of her feet.
Now once she is eagerly eating from the glove at foot-height garnished with a tidbit, hold or put the meat a little distance away from the glove. She will reach to get the food. Repeat this process after she eats the food, and move back a bit farther. She will contort herself into odd positions as she tries to get at the food without jumping or flying, but eventually she will give into her greedy nature and hop to the glove for the meat. Repeat this same action, every time moving a bit farther back in response to each successful feeding.
At this point, two things should be done - one, begin getting your new hawk accustomed to the world and its oddities; barking dogs, cars, the household, and bring her outside. Also, she should not be perched outside until she has begun flying to you on the creance. If she is, she may fly against the creance repeatedly and injure herself as she has not fully come to understand the life of a captive hawk.
Once she has begun hopping the length of the leash, now comes the time for the use of the creance - a long, thin line (suggested creances are 30 to 100 feet of braided nylon twine or very thin parachute cord in a similar length - do not use twisted twine or fishing-line monofilament for this). Take her to a short length lawn (football fields, large backyards, pastureland with short grass) and bring a perch. Place her on the perch and holding onto the creance in one hand, offer her a tidbit on the glove with the other. She should hop to it as eagerly as she had done indoors. Repeat the process, and back up a few feet. She should fly immediately to you without delay. If she turns round on the perch, flies in any other direction other than towards you or tucks a foot up, then she is not yet hungry or well manned enough to begin this stage. Man her or put her up for the night and begin the next day if she does this.
If she does fly to you with eagerness, then fly her as far as the creance will allow. A length of 50-100 feet is acceptable. She should be so eager to fly for her food that she should be coming to you BEFORE YOU CALL FOR HER. Most likely you will not even be able to get to 75 feet before she takes off after you. If you must wait longer than one minute, flap your arms, shout, or put up with any other such nonsense then she is not ready for the ultimate stage of training - free flight.
Before beginning free-flight, there is one more thing that should be addressed; the falconer's insurance policy - the lure. Even if you never again use the lure, train her for it now. Fat hawks with no intention of returning to the glove will happily nail the lure out of greed. Tie a full crop's worth of meat onto the lure after calling her to the glove on the creance a few times. You should do this a time or two to cement the concept of 'lure = a full belly' to the hawk. Once she is done with the food on the lure, offer the garnished glove and hold onto the tidbit hard to prevent her from bolting it down or taking it to the ground. Eventually she will tug and be forced to step to the glove to eat. Hide the lure as she does. Out of sight, out of mind or possession for a hawk.
If she is a falcon, the lure will increase in importance from here. The next major step in training a falcon is to take the lure away from it just as it is about to lay foot upon it, making the bird wheel round, and attack the lure again. Once this is achieved the lure will be swung around artfully by the falconer in wide circles, encouraging the bird to make more 'passes' at the lure, to attempt to catch it. This becomes a game of "keep away" between the bird and the falconer, a game which challenges both of their skills and dexterity. The falconer's job is to keep the lure enticing, yet pull it away at the last moment, while the bird tries coming in faster, turning more sharply, and even anticipating the falconer's actions. A bird may make upwards of forty passes at the lure once fit. If the bird should catch the lure, the falcon is rewarded with the small piece of meat tied securely to the lure. At the end of the game, the bird is generally fed a goodly portion of food as reward for the entire exercise.
Another useful thing to do before free-flight is to call the hawk still on the creance down from a height. For some reason, a new hawk who finds itself high up in a tree can develop a habit of being 'blind' to the falconer. This can mean she is too fat, not manned (acclimated to humans and the human world) well enough or perhaps being up high is simply more enjoyable than being down near the ground. Either way, she can be trained to avoid this hawkish inclination of being up high and not coming down. Throw her to a rooftop or other similar object that is at least twelve to thirty feet up. DO NOT choose a tree as the creance tends to get tangled up in the branches. Allowing your hawk to get hung up by the creance is an insult to her... and it sets back her training so it must be avoided at all costs.
After being trained to the lure, she will be prepared for free-flight. Experienced falconers have seen the highly attentive 'look' of a hawk who is ready for free-flight... she is focused only on the lifting of the glove, the blow of the whistle, even the reaching of the falconer for the food in the food bag. These are the same actions that a novice should look for. Once she is at this stage, remove the creance in the flying field and call her. Most likely she is already on her way. If she does swing up into a tree, try calling her to the glove once more - then offer the lure with its full ration of food attached. She should plummet from the trees to either the glove or the lure.
All that must be done from this point is to take your hawk down, make sure she is at proper weight and that the wind is not too great for her (passage or new young birds especially can be lured off by the prospect of a thermal) and to bring her to a field where prey is known to be.
Once the relationship is established and trustworthy, the pair go out into the field. The bird is unhooded and, in the case of a falcon, quickly takes to the air. Hawks either hunt from the air, from a soar, from a nearby perch, or from the glove itself. Once the bird is untethered, the falconer becomes the bird's servant, dutifully seeking out the quarry and flushing it for the raptor. The raptor then takes chase, providing stunning aerial maneuvers. Hawks can seem to defy physics, and the falcon's stoop (dive) is recorded at speeds up to 240 miles per hour, and her turns have exceeded 29 Gs! To many falconers, this aerial display is the greatest reward, this close witness to nature at its most impressive gaining him a front row seat to what is inarguably the greatest airshow on earth.
Hawks are not exercised by chasing the lure, but instead encouraged to fly from tree to tree as the falconer walks along by occasionally offering the tidbit-garnished glove. Some falconers employ a method called "jump training" in which the hawk is required to fly nearly straight upwards to a height of 10-12 feet for a tidbit of meat. This can be performed many times, the reward being given intermittently (as psychology principles have taught that the intermittent reward is a stronger reinforcement,) to gain strength and stamina.
In order to track a raptor who has flown away, many falconers use radio telemetry. Typically a transmitter is temporarily attached to the leg at the jess or on a bewit. Sometimes a mount for it may be attached to one of the center tail feathers by very careful application of a small drop of Superglue. Recently, a lightweight harness made of Teflon tape has also been employed as a means of hanging the transmitter off the middle of the bird's back (out of the way of the bird's flight and footing, so as to minimize interference with the hunt.) The transmitter emits a radio Beep, which the falconer can track with a portable receiver. By listening to how the signal gains or loses strength a practised person can gauge if the bird is sitting still, if it is flying, and what direction it is going in. Practice with telemetry is very important, as there is no time for learning when a falcon is flying away!
Weight is key, especially in small species. Some falconers recommend beginners start with a kestrel, a tiny species of falcon. They are ready sparrow hunters, and as they are so small one must pay close attention to their weight and training to avoid hurting them. Similarly, some falconers detest the use of Harris' Hawks by beginners as the birds are so forgiving the novice falconer can make constant mistakes in the bird's care and still hunt successfully. If the bird is a non-imprinted captive-bred, it is very important to establish in the bird's mind that food comes from the falconer. The bird will be getting accustomed to its new 'furniture' (equipment) as well as its new owner.
Since the success of the Harry Potter series, some novices are desperate to keep (or hunt with) an owl. Seldom does this lead to success. Many states in the U.S. provide for keeping a great horned owl for hunting, but it is a difficult venture. Owls can be a horror to hunt with, as they find prey more by hearing than their diurnal(daytime) counterparts. Even the Great Horned Owls and Eagle Owls, which can see well enough during the day, will still prefer hunting at night.
There's also greater risk to the owl when it is out during the daytime. All of the diurnal raptors see owls as mortal enemies in competition with them for food and territory. Accordingly, wild birds of prey will attack an owl mercilessly if given the opportunity, even killing it if they're able to do so.
Laws also carefully regulate falconry in many areas. Throughout the United States, for example, you will be required to pass a written exam, build facilities, have them inspected, serve a two-year apprenticeship, and keep diligent records on your birds. In order to catch a wild bird, you may need additional licensing and permission.
Contacting a local falconry club or association is usually the first step to learning.