JWN Arts & Hawking 

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Breeding Notes
copyright Jim Nelson, 2017

Basics of Breeding

       Like other sections on this website, the aplomado falcon breeding chapter will grow and change over time.  What is being presented now are the basics, based on the author's experiences with breeding this species since 1999.   Included are insights from other aplomado breeders such as Jim Ingram, Troy Morris, Raul Ramirez, and Justin Stovall. General information that relates to raptor breeding in general has been influenced by Dan Robertson, Bill Meeker, Brian Sullivan, along with the literary contribution of the Peregrine Fund and Dr. Nick Fox.  

Natural Pairs and Pairing

         As more pairs and raptor propagators became involved, experimentation indicates allowing parents to set and hatch their eggs and also raise their young may be more viable than originally speculated. One of my pairs laid 3 eggs in 2010, hatched all three, and reared all three chicks to hard-penning.  In 2011, Jim Ingram of Omaha, had four of his pairs hatch 8 out of ten eggs, all fertile. That same year Nelson (using the American Bird Abatement Service breeding facilities) orchestrated natural reproduction with 17 pairs, 15 of which produced eggs that season.  The biggest surprise being that one pair hatched two chicks, raised them until they fledged out into the chamber from the nest ledge, and then the parents laid a second clutch, their first young still in chamber.  Few large falcon species will do this, but Tom Cade (pers. comm.) states it is common among kestrels, and it is also well documented to occur with Harris’ hawks, another social raptor species.

        When selecting individuals for natural reproductive pairing in the chambers, it seems almost any healthy aplomado will do.  Having said that, pairs consisting of individuals who themselves were parent-reared and who were subsequently extensively manned or fully falconry trained and better still actively game hawked are the top choice for successful pairing. They are both fully “hard-wired” to breed naturally, and tamed down such that they do not expend their emotional and physical energy in the chamber thrashing about each time a human is perceived to be in the vicinity.  It seems particularly important for males, coming to a breeding project as wild-natured individuals, receive extensive handling for falconry, because between the two sexes, a skittish male is the least desirable.  If he is too busy being nervous, he may not make a good mate.

       Next best are the cresche reared (sibling reared) individual who become “dual socialized.”  From their earliest days, these individuals spend time in company of both their own kinds and humans.  While the parent-reared birds may be easiest to get going in the breeding chamber, the dual socialized birds eventually do get there, and their tameness is an asset, because aplomados can be very high-strung which interferes with settling into the matter of courtship and reproduction. Dual socialized aplomados that are flown for falconry, especially if they are flown at least part-time in a cast or a group, do very well in the breeding chamber as they do not bang about causing a ruckus and threatening to hurt themselves every time the breeder must enter the chamber on a necessary task. 

       The social imprints (those that are “fully” imprinted on humans) reputedly will also breed naturally. However, these individuals are probably the most risky bet, and we have known individual imprints that wouldn’t court their mates.  This is probably most significant with the males, as if they do not recognize the females as potential mates, they may not initiate courtship and normal copulation. 


Breeding Chambers

       Natural pairs have done well in 12’ long by 12’ wide by 10’ high enclosures with the roof sloping to 9 feet at the south-facing rear. Smaller dimensions might work, but larger chambers offer more exercise. Males can fly continuous laps inside the 12 by 12 foot enclosures with obvious benefits for physical condition. With natural pairs, the bigger the breeding area the better, but the 12 by 12 dimension is probably a good baseline from which to start your design from.

        If avoidable, do not create openings on vertical walls through which the breeders can see out.  This becomes a constant source of irritation to them as any passersby or family member must be scolded and this pulls the breeders away from the nest ledge where they should remain to incubate and care for the very young chicks. Every effort should be made to make the chambers as private and removed from everyday disturbances as possible.  Propagating natural pairs of aplomados is not something easily shared with friends and families, because to take friends on tours through your facility will ultimately work against you in terms of upsetting your pairs and potentially introducing pathogens on the clothing and shoes of your visitors.

       Overhead openings, protected by small diametered mesh will provide fresh air and light. Unfortunately, skittish males may fly upward and hit the overhead netting repeatedly when disturbed which potentially can damage their cere, lores or supra-orbits.  Hitting the netting also makes them vulnerable at those moments to predator attack from the outside. Too many breeders have found out the hard way that a cat or owl may not be able to get all the way in, but it only takes one foot inside the mesh to grab a panicked breeder and your precious aplomado is killed nonetheless. 

       One-half inch welded hardware cloth is escape-proof and prevents predators (such as great horned owls, raccoons, or cats) from reaching downward into the chamber to grab a panic-stricken falcon. Over two decades and with around twenty different pairs, I have only had a single male collide with unbarred hardware cloth of the skylight with such consistency and force as to effect the soft tissue about his eyes. Even though his injuries were minor and did not effect this male's eyesight or general health, because it involved the yes, bars were installed and this problem was corrected.  Other males, and some females, have nicked their ceres slightly which caused a minor amount of bleeding, but the 1/2' mesh doesn't allow the birds to insert their faces into the opening far enough to cause deep-tissue damage.  These tiny and very incidental cere "dings" do not seem to warrant the significant expense and labor of installing barring.  That will be each breeder's call.

       Much of the enclosure should open directly overhead, protected as described above. Access to direct sunlight must be prioritized.  Design your windows to receive as much direct sunlight as possible throughout the day.  Locate perches near these windows to allow the breeders to find sunlight whenever they feel the need for it.  Perches must be designed to allow them to sit comfortably facing away from, not just toward, the direction of the entering sunshine.  If constructed correctly, you will observe your breeders frequently sitting in a patch of sun, back toward the light, with wings and tails outstretched as though they were drying themselves after a bath.  This behavior is the result of their instinctive need to increase Vitamin D3 production in their systems.  The preen gland oil they smear onto their feathers with their beaks during preening is modified by the short-lengthed UV waves from the sunlight. It is re-ingested during the next preen now in a form their bodies can use to convert into Vitamin D3. Vitamin D3 is associated with a variety of health issues, but in this context embryo vigor and possibly gender production ratios (how many males versus females the parents produce) can be influenced by D3 or other factors affected by direct natural UV waves.

       While it is possible to include additives to a hawk’s diet which can replace the missing D3 provided by direct solar radiation, it is difficult to gauge whether or not sufficient amounts are actually being ingested by the natural breeders who are not fed on the fist and thus closely monitored during meals. Artificial light bulbs and tubes providing the right kind of ultra-violet waves in the correct amounts are expensive and short lived. A profusion of natural sunlight is the best solution. 

        The nest itself can be a simple shallow, round rubber or plastic pan no less than 18” in diameter.  Be sure to place a circular piece of foam padding (a thin memory foam would be ideal, but in any event a thin cushioning layer at the bottom so if the incubating birds "drill down" through the nesting material, the eggs are not laying on a hard plastic surface.  Long pine needles can be used as abase layer on top of the foam, layering up about 3/4 of the way to the rim.  The final 1/4 to be filled with cut pieces of raffia.  Raffia, a natural grass that is dried, cleaned and used for floral arrangements as well as other decorative applications, can be purchased in bundles at craft stores. The long stems can be cut down into 2 or 3 inch-long pieces, and the female will fashion a depression in the center in which she will lay her eggs. The adults will also take individual raffia pieces and strip them lengthwise into finer strands that curl up and form a soft, bed-like bundle at the center of the bowl. The raffia needs to be replenished from time to time. One male methodically removed all of the raffia rushes from his nest, leaving only the pine needles behind. Imprint females should be given raffia, though, as it provides a deep, cushioned bed for her eggs. 

      One caution for those using raffia, Jim Ingram recounts a situation where one of his aplomado chicks became compromised by a raffia strand becoming wrapped tightly around the chicks leg such that its circulation was cut off like a tourniquet.  So one must be sure that each strand is reduced to somewhere between and inch and perhaps three inches at the most to prevent the winding of thin strands around the chicks appendages.  I have also seen this happen from strands of fiber fraying away from the edges of cheaper grades of astro turf, so one must guard against having long thin fiber strand of any  kind from any source near the chicks within the chamber.

        Wood shavings at the surface may stick to meat and be consumed accidentally by the chicks. This may lead to blockage in the crop or gut that can be harmful or even fatal. Wood shaving are appropriate to use if one is planning to remove all the eggs for artificial incubation.

       Regardless of material used to form the nest, you may find the parents hide the first 2 eggs of a natural clutch beneath the nesting surface such that you may not realize your pair has a clutch until the full set of three is laid. Even with remote cameras stationed right over the nest, it is possible for egg laying to go undetected if the parents are secretive enough to lay in a depression and then cover over the top with either raffia or shavings. If you are observing behavior similar to incubation (lying in a prone position in the nest bowl) but when the parents are off the nets you do not see eggs there, some may be hidden. Clues to look for will be the disappearance of an small but well defined depression at the center of the main bowl. One day there is a deep cup-like depression and the next it is gone. There may now even be a almost imperceptible mounding there. That, coupled with incubation like behavior (setting in the nest bowl for hours at a time) are signs there may be eggs.  While one is reluctant to disturb incubating parents, the test will be to have someone watching the camera monitors while another person gently bumps the incubating bird off the nest.  This is best done at the normal feeding time when some amount of disturbance is normal to avoid a traumatic change in daily routine. Once the bird is out of the nest you should be able to observe an egg or eggs if a set has been started.

       A platform surrounding the nest provides secondary protection for the young chicks from death by falling.  Convenient and staggered perches that allow the young to explore down to the floor and back up again are favored by some hawk breeders and may prove useful in the parent rearing of aplomados as well. 

        Locate the nest well up off the ground but with plenty of clearance under the ceiling for easy access by parents. If possible, place the nest in the northwest corner such that the low-slanting early-morning sun falls on it. These early rays are warming and provide healthy doses of ultraviolet radiation. By midday, the sun becomes the enemy, but it will have moved to a position blocked by the western overhang which now casts shade on the nest and provides relief to the chicks. Adults can move into the sunshine at the eastern side of the chamber, but babies remain shaded. If this exact arrangement is not possible, locate with afternoon shade as the priority.  

        In northern climes, where midwinter temperatures may reach frigid levels day and night for weeks on end, a “heat can” should be installed above a sheltered perch in every chamber. This is an infrared heat lamp suspended in an upside-down, 6-gallon galvanized-metal pail attached directly to the ceiling so the opening hovers about 2 ½’ above the perch surface, but the top is flush with the ceiling to prevent attempts to land on it. The perch should be long enough to allow birds to shift either closer to or farther away from the heat. Power cords must be installed using common sense. When the daily “high” is predicted to be in the low 20s, especially over a period of many days, I use the lamp at night. If the high is predicted in the teens or below, I run the lamps continuously. One concern with this heat-lamp system may be an effect on photoperiodicity. After several successful breeding seasons which followed the use of this system during the winter months, I have not found judicious use of infrared lamps in deep winter to interfere with breeding in spring.


        A diet of adult-aged (8-week-old) small-breed, high-quality coturnix quail—such as those 

currently produced by the Bird Boyd’s Company of Pullman, Washington—has proven sufficient to stimulate fertile egg production. Obviously, the closer the diet matches that of wild aplomados, the better. However, wild aplomados feed primarily on small birds currently protected under the Migratory Bird Treaty Act. To provide a legal wild diet, one is pretty much limited to starlings and English sparrows. I personally do not have the time to trap or net the large numbers of English sparrows required to feed all the aplomados I have in my project. Starlings worry me. There have been reports of poisoned starlings being the cause of death in small falconry birds such as merlins and kestrels.

       Small-breed coturnix quails—fed a high-quality diet—are free of disease, parasites, and poison, and they have proven to provide adequate nutrition. Since they are a small breed, they are more likely to be consumed (more or less) in total, with increased calcium and nutrients entering the aplomado’s system than if these small falcons were to be fed on the larger breeds of quail. My breeders certainly appear to be in excellent condition (good color in feather, feet, and cere) with very high fertility, and the young all grow up to be healthy specimens. Recently, I have begun sprinkling the quail daily with a recommended raptor vitamin supplement to maximize resilience and health. I have also implemented the practice of completely eviscerating quail dropped to breeders to eliminate one potential source of salmonella in the chambers.

       Providing live prey birds (in the past I have used small pen-raised quail for this) just prior to and during the courtship can significantly stimulate and encourage breeding behavior. However, a caution may be that live birds set inside a closed system such as a breeding chamber can potentially introduce a source of some type of microbial infection.  Any live bird set inside the chamber brings with it all the microbes living in its gut and bloodstream.  One must feel very confident about the condition of such birds before doing so.  Another technique cited by the Peregrine Fund is to stimulate courtship by cutting dead quail carcasses into many smaller pieces so the male must deliver multiple “gift” of food to his mate. The more deliveries in a day, the more the courtship frenzy is stimulated.

Introducing Mates

       The introduction of aplomado mates to one another may be easier and safer than with other raptor species.  I have personally introduced or directed the introduction of over 20 pairs together. Moments of aggression I have witnessed was with one young male attacking an older female upon introduction and 2 older females threat posturing at intended males. I chose to leave the aggressive male in with his female and several days later they were shoulder to shoulder.  In the other instance, the posturing female was replaced by another that displayed no aggression at all. In the third case, the male (an older experienced breeder) did such a good job facing the aggressive female I chose to leave them to sort it out. Being the larger and more powerful sex, the posturing females represented real threats to their mates, whereas the attacking male did not to his. 

        Some breeders with experience with other raptors have made an effort of perching prospective mates near one another for many days to accustom them.  I usually place pairs in a chamber together and keep watch for a few hours. Prior to doing this, I do make sure both birds are "fat and sassy" and there is abundant food in the chamber. I also clip talons and beaks to lower the impact of any aggression should it occur.  In some cases, I will place the prospective male in the chamber for a week or two prior to placing in the female.  This allows him to stake a claim to the territory and the female comes onto his turf rather than the other way around,

         I have personally had two incidents of female aplomados killing their mates in the chamber, and in both cases it was almost certainly linked to a stress producing activity in the environment.  In one case, a minor construction project in the breeding barn hallway was only supposed to take a few hours stretched out to matter of days.  By the end of that time, a female in the chamber nearest the place in the hall where the builder was storing his materials may have killed her mate (though there is also reason to speculate the male may have died during a panic flight by colliding against the chamber wall).  In the other, a winter cold snap may have caused the female to become aggressive if she felt her male wasn't delivering the food fast enough and in enough abundance. I am aware of at least one other case of the female killing her mate, and that occurred when the breeder had construction and some tree trimming occurring nearby. 

       These anecdote are shared by way of a warning to those aspiring to breed aplomados. These birds can be very sensitive to disturbances, and there is good reason to believe stress generated by disturbances may manifest itself as “displaced aggression” on the part of the female toward her mate and possibly her chicks.  Deep privacy should be prioritized at all times.  If there is no way to avoid prolonged disturbances, be sure those activities are scheduled during the non-breeding time of year, and arrange to temporarily place all for the breeders in cool and darkened location until the activities are completed.  Alternately, if removing all the breeders is not possible, at least remove all of the males, or all of the females, leaving only one bird in each chamber so they do not attack one another when distressed. 

        As a related thought, the truism that falconry-trained raptors make the best breeders is doubly true with the aplomado.  Although you can breed untrained aplomados (I have for many years) the pairs that are the easiest to deal with are the falconry trained pairs.  I notice the difference when I am compelled to enter the chamber for maintenance or banding.  I also see this difference during times I have to remove the pair for cleaning and other important interruptions.  The falconry-trained birds are far less stressed by these invasive procedures, and that will lower your stress as well.

         One interesting behavior observed between confirmed and active mates is the behavior of the female stimulating the male to defend the nest.  If a female detects the presence of an intruder (perhaps the breeder peeking through a peephole) she will lunge at her mate and, in some cases, assault him to the point where he is pinned upside down beneath her as though she were intent on killing him.  Do not panic, she will soon let him up, and, incredibly, he gets the message and flies straight at the peep hole in an attack display, or he may go to the nest to defend it. If he does his job sufficiently well, she watches approvingly, kekking her anger in support of his efforts.

       Another much more peaceful interaction observed is the feeding of the adult male by the adult female. At various points during the breeding season, if there are no young in the nest, the female’s instinct to feed is so strong she will tear small bits from a quail and proffer them to him as though feeding a chick.  He will reach up eagerly and accept these just as would a chick; a touching sight and some evidence as to why high-level tidbitting may be so effective as a training method. 

Daily Care During the Breeding Time

       Once the breeding season is under way, eliminate all intrusions into the chamber. Supply food and water through chutes and spigots from the outside. Clean chambers well before courtship, then again after the last chick is safely fledged, if any are left with the parents to rear. Today’s security cameras are inexpensive enough to be well worth installing in every chamber.  At a minimum you will want one suspended directly over the nest used to monitor the arrival of new eggs.  A second camera to give you a broad view of the chamber is excellent for monitoring courtship and copulation, but the nest cam is vital as you must keep track of the dates the eggs were laid in order to help calculate arrival of chicks and strategize dates for banding, etc.


       Most aplomado pairs become ready to breed in their second season. Most of my pairs have done so as have many in the Alton project and a number of pairs around the country held in smaller projects. In terms of annual egg laying, some pairs in both projects have been relatively early layers. I have received eggs as early as January 20th. Justin Stovall of Florida had a clutch in early January of 2011, but the clutch was infertile from a previously viable pair, so it may be the female was ready to lay eggs before the male was able to produce viable sperm to fertilize them. In the northern regions of the United States, first clutches are typically laid by most pairs from early March or to early April. I have had a second clutch laid as late as May 25. Aplomado pairs appear to be good sitters and most can be trusted to sit first clutches very faithfully. However, if their first clutch is pulled, they may be less reliable sitting subsequent clutches. There have been enough incidences of aplomados hatching chicks only to have the chicks “mysteriously’ disappear within the first 24 hours to make on pause before trusting them to the task of rearing.  Having said that, there have also been numerous documented successes as well, and evidence points to parent-reared young as being better natural breeders later in life, and it is hard to beat them as candidates for sport falconry.


       Once a breeder has an established fertile pair of aplomado falcons, a significant question becomes how to manage the egg (and therefore progeny) production.  As stated above, it is probably wise to allow the first clutch produced by a new pair to be naturally incubated and hatched by the parents, and to allow the parents the opportunity to raise the chick themselves.  I write chick, singular, because it is often the case that a new pair will produce a single fertile egg during their first successful fertile clutch. while there may be a great deal of anxiety about letting the new parents rear the chick, and there is a real danger they may not be very good at it, the choice to take the eggs from a new pair can be equally problematic in the long run, as that disruption and failure of the first clutch (from the bird's eye view) can lead to reproductive dysfunction in the future.

       After a first successful season, the breeder may want to just allow the parents to hatch and rear a single clutch per year.  This has advantages in that the chances of the one clutch be vigorous and healthy are improved by not stressing the pair through multiple clutching, and one is sure to produce "parent-reared" young which are popular among falconers.  The disadvantages are that some pairs are not very good at rearing their young, or you may have problems in the chamber with pests, disease, or weather factors.  In other words, by leaving the eggs and young in chamber you assume some risk.  So, for some, artificial incubation and hand-rearing will be preferred, and if that is the case, there is a good chance you will be dealing with moe than the natural number of eggs and young in any one breeding season..

       On the question of multiple clutching versus "extending" pairs there is much to consider.  I will start with my opinion that extending the clutches of a natural pair of aplomados is not a fruitful approach.  Typically, the practice of extending a clutch (ie: pulling eggs as they are laid to cause the female to continue producing more and more eggs) is best practiced with imprints who are being artificially inseminated.  Under these circumstances, you have control of the fertilization of each egg and therefore if your desire is to produce an abundance of eggs, you can do so with a reasonable expectation of high fertility.  However, with natural pairs, and especially high-strung raptors such as aplomados, pulling eggs as they are laid may indeed produce more eggs, but fertility is very likely to plummet. That is because the constant interruptions required by pulling the eggs will upset the pair and interfere with courtship and copulation, and even if they are not overly upset, the constant uninterrupted production of eggs will push the tiercel's ability to cover all those eggs sufficiently.

       A better solution for natural pairs of aplomados is to multiple clutch if numbers production is the goal. The multiple clutching approach is very likely to produce a similar if not identical number of fertile eggs as extending.  One breeder stated that he was able to produce 16 eggs in a single season from one natural pair by extending, but fertility was at about 50%.  That is 8 fertile eggs.  My experiences with double clutching is that some pairs that normally produce 2 eggs in a clutch will produce 5 - 6 fertile eggs in a season, and pairs that normally produce 3 eggs in a clutch will produce 7 - 9 fertile eggs in a season.  That is close enough (or in some cases better) than the extending that it makes sense to allow the pair time to lay a clutch, naturally incubate that clutch for 8 days past the last egg laid, then rest for a couple of weeks before laying the next clutch as so on.

       Young aplomados grow through three distinct feather phases from hatch to fledge. In the first, the very young chick is covered with a layer of cream-colored dandelion-like down. At about one week, an underlayer of coarser, dark-gray down begins to emerge through the creamy overcoat. At 14 days, the young bird is nearly all gray with its head still completely creamy white. By 17 days, the head will become mottled with gray. And by 3 weeks, the young aplomado will be nearly solid gray with indications of cream at the throat and over the eyes. The remaining patches of light-colored down seem to correspond with future areas of light-colored throat and head feathers. At this time, contour feathers begin to emerge at face, tail, and wings. By 1 month, the once-gray wooly toddler blossoms into a gorgeous orange and charcoal falcon.

       Some very young aplos never develop a full coat of cream-colored down but remain only sparsely covered over much of their bodies. Once the gray wool is in, older chicks remain only sparsely coated or even fully bare at the throat and on the thighs. During this stage they have a baby-passerine appearance, not unlike a young robin. This may be an adaptation for high plains or mountain-desert dwelling, where days blister and nights chill. The unfeathered patches provide the young bird bare skin surface area through which excess body heat can be lost during the day. At night they tuck into their built-in wool blankets and huddle with their siblings to stay warm.

       Incidentally, USFWS seamless band number series starting with the letters “RT” (does not stand for “red tail”) have an inside diameter of 8 millimeters and are recommended for use on both sexes. These bands are a perfect fit in the females and only slightly loose on the males. By using only RT-series bands, one cannot make a “mistake” and put a bad-fitting band on either sex. The bands should be slipped over the right foot and settled around the tarsus at about 10 days.

       Until the day comes when access to wild aplomado falcons is possible on a large scale, captive breeding will be the avenue to provide continued access to this wonderful falconry bird.  Natural pairing of aplomados is much easier and far less expensive than that of larger species such as peregrines or gyrfalcons. Adequate space, lots of privacy, abundant high quality food, fresh water, and access to copious amounts of direct sunlight will be the key to successfully rearing an ongoing source of young alethes of your own.








Aplomados are sleepyheads. Don’t panic if the aren’t up at the crack of dawn.