Amazons are not sexually dimorphic although small but overlapping differences in beak, head and body size do occur between the sexes. Incorrect attempts have been made to determine sex by these differences. Last year I bought a “pair” Double Yellow Heads which had major differences in body size and head size. However, surgical sexing revealed two males; no wonder the breeder had no success with this "pair"!
Methods of sexing presently being used include DNA blood sexing, chromosomal karyotype, and my favourite endoscopy. Although noninvasive techniques, which simply need a blood sample, are of no risk to the bird they only tell you the sex of the bird. We recently surgically re-sexed a Red Lored that had been DNA sexed as a female. Well the bird was a male and there was apparently a mix up in paper work between the lab, vet and owner!
Endoscopy has proved to be a more useful management tool, if performed by an experienced avian veterinarian, for it can also evaluate maturity, the general condition of many internal organs plus the bird will be immediately identified by a band. The presence of air sacs allows main organs to be viewed including testes and ovaries, making the bird an ideal patient for laparoscopic examination. This allows the veterinarian to make a health check on the bird long before any external signs of sickness are given by the bird.
The equipment required for endoscopy includes a light source, fibre-optic light guide, a small diameter endoscope and anaesthetic gas machine all of which can cost at least $5,000. Be careful when a veterinarian who does not have this equipment says that the risks of surgical sexing are too high and offers blood sexing. We have now surgically sexed about 1,200 birds with Avian Veterinarians in Guelph, Toronto and Montreal with only two loses. A very small surgical incision is made necessitating the use of isoflurane, the anaesthetic of choice. The two birds that died both had other complications, one was an extremely obese Maximillian Pionus and the other a baby African Grey with major crop burn plus the veterinarians involved were both inexperienced.
Veterinarians appear to be charging about the same for both procedures so the extra information from endoscopy (e.g. gonads are scarred) may save you a lot of time and effort. Both sexing procedures can be performed on young birds before they are sexually mature, which is useful for structuring breeding populations and exchanging birds at a younger age. Chromosomal karyotype (different from DNA blood sexing) can detect birds with genetic abnormalities such as triploids but these birds are rare. It is more important to know the quality of the internal organs of a bird which can be done in a very cost effective way by surgical sexing.
Leg banding is commonly done by most clinics surgically sexing. By convention, the right leg is banded for males, and the left is used for females. All of our birds are banded and we have only had a few minor problems. It is important that the space between the butt ends of an open band is as small as possible for if this gap if left too wide it could allow the cage wire to pass through thereby hooking the bird. The bird will then panic and may in the struggle break its leg or chew off its foot. Close bands on domestic reared babies are quite safe and are an important means of identification. They can verify that the bird is domestic since they can only be slipped on very young babies and if the breeder has kept good records, the parentage of the bird.
Sexed, pair-bonded birds must be placed in housing that will be conducive to breeding, noninjurious to the animal, easy to clean, and offer visibility of the pair. Housing should be large enough for the birds to exercise and feel comfortable and be durable to withstand the destructive nature of parrots. Each species individual requirements must be considered when deciding on the type of housing to use. Tropical birds kept in cooler northern climates should have indoor quarters or be protected from rain and have other sources of warmth such as infra-red heaters.
Indoor housing has many advantages including the ability to control temperature, humidity, hours and intensity of light to optimize breeding. Other advantages of indoor breeding are: elimination of rodent problems in a properly designed facility, no contamination from wild birds, insects (e.g. a parasite passed by bugs in Southern USA is still killing Cockatoos) and the reduction of disturbances from predators, cats and robbers interested in stealing expensive species.
At HARI most of our birds are housed indoors most of the year, similarly to many northern breeders. Indoors we can operate under “winter” conditions i.e. misters off, eight hours of light and cooler temperatures or “summer” conditions i.e. misting, 16 hours of light and warmer temperatures. Green house sprinklers suspended over flights are an excellent way to increase humidity and give the birds a shower. When our misters are on, the air is saturated with tiny water droplets and our pairs go into a bathing frenzy especially at the start of the breeding season. Some birds like to splash around in their dish of water, but most prefer to be “rained” on. Sprinklers are controlled electrically via solenoid valves connected to timers with 15 minute intervals. These timers can turn on the systems any number of times a day and can be set to skip days.
The main disadvantage to indoor flights is that birds are denied access to sun and rain and need expensive ventilation and heating systems. Although bathing facilities or sprinkler systems and “natural” fluorescent or sodium lights can stimulate this, we are going to move some of our breeding stock into outdoor flights during the summer months. But many parrots including those we are concentrating on here have reared young indoors, often in circumstances which might be thought far from ideal. The problem with below standard indoor facilities is the increase in disease to both the birds and their keepers who must breath in the concentrated fecal and feather dust.
In 1969 Ramon Noegel, a leading breeder of endangered amazons in Florida, changed the style of his aviaries from the traditional walk-in type to aviaries suspended about three feet off the ground. These are actually large cages since they are made completely of wire and usually are smaller than aviaries. Breeding birds in this type of suspended flight has become popular in the last few years due to the many advantages of this system. They cannot be entered, thus they provide the occupants with a feeling of security. Birds soon learn that a person cannot get to them and even some of the most nervous specimens will calm down.
This arrangement also allows discarded food and droppings to pass through the wire bottom and out of the reach of the parrot: a most hygienic arrangement which allows easier cleaning by keepers. The nest box is attached to the outside of the aviary which facilitates easy inspection with a minimum of bother to the parents. The main problem with these suspended cages is that aviculturists tend to make them too small for the birds to exercise.
A longer, narrow flight space is preferable to one of more cubical dimension, in order to afford the birds ample flying space, since vigorous and frequent wing exercise is most certainly conductive to producing healthy and sturdy bodies. A length of six to ten feet and a width of three or four feet I would consider adequate for amazons.
Birds feel more secure if they can perch above our eye level thus hang or support the cages as high as possible. A space of four feet between the bottom of the cage and the floor will also facilitate easier cleaning.
The door entering the bird room should be tight fitting, have a viewing window, and adequate width for the passage of cages. Every room should have a double door. One door, opening into a little vestibule, which is closed before the main room is entered. This minimizes the amount of air exchange between the bird room and corridor, an important consideration in disease control.
The floor of the bird room should be made of concrete and coated with a nonslip, corrosion and dent resistant paint. Floor and wall junctions should be covered and a floor drain should follow the floor perimeter. For proper floor drainage, a high centre sloping down to the drains will allow for fast washing, with high pressure sprays. The walls of the room should have a smooth surface for ease in cleaning, be vermin proof, water resistant and have large viewing windows for behavioral observations on the birds. Suitable bird-proof air vents should be placed in the bird rooms to provide a down draft ventilation flow with at least three air changes per hour.
Parrots need large, strong and secure food containers. They should hook onto the side of the flight and, along with the water bowl, be kept clean. An established feeding routine: same time, same person, same bucket, etc. offers the keeper an opportunity to observe any unusual behaviour-fighting among cage mates, breeding activity, change in droppings due to illness or egg laying.
To maintain the birds welfare and reduce psychological stress, the preferences and aversions of each species should be taken into account when designing a species specific artificial environment. Perches should be made of wood, the thickness depending on the size of the birds. Naturally, the larger the bird, the thicker and heavier the perches required. So far as placement is concerned they should be set far enough apart to give the birds as much flying room in the centre of the cage as possible. To prevent birds from soiling perches they should not be placed directly below each other. Placement and size of nest-boxes are important factors in encouraging a pair to nest. When building artificial nests, it is important to try to simulate the nest conditions found in the wild. Most birds prefer a confined nest with a small entrance hole.
We use vertical nesting boxes sized 12"x12"x24" deep for our smaller amazons and 15"x15"x30" deep for the larger Yellow Head and Nape Amazons. We use metal boxes which are then lined with 4 cm thick spruce. The wood is cut to fit tight and is wedged into the metal box with a sledge hammer. Thus no nails or screws are used. Our amazons chew the nest box wood a little but not as much as our cockatoos who usually chew up all the wood within a few months.
Deep nest boxes should have a stable ladder placed inside them from the nest material to the entrance or the bird may become trapped and be unable to get out. A small door should be placed near the bottom of the nest-box. This entrance is used for inspection of eggs and chicks and for adding nesting material. The most common materials used are pine, cedar shavings and peat moss.
Specialization & Pairbonding
There are many management benefits by specializing in selected species and building up numbers of the same species rather than having only one pair of each of many species. Simply placing a pair of sexed birds together into a flight is not recommended. Compatibility is no guarantee when you place a female with a male. Pairbonding or letting each bird choose their mate is the best method, as it dramatically increases the chance of getting a compatible pair.
Placing at least four mature birds (two of each sex) of the same species into a large cage should result in at least one compatible pair. It may be especially noticeable when a nest box is placed within the group. When the dominate pair take over the nest box or chase away the other birds, remove the others and leave the bonded pair. When working with younger birds, it may take months or years to observe serious pairbonding. But this method enables the aviculturist to get compatible pairs that are most likely to nest earlier.
Amazon pairs develop strong bonds and will remain together even when put back into a colony situation. Parrots in which the pair-bond is strong spend hours sitting together, usually with their bodies in actual contact. Much of this time is spent allopreening. By nature they are very affectionate and two individuals of the same sex can act as a true pair, indicating the need for sex identification markers.
Male birds ejaculate scant amounts of seminal plasma which usually provides nutrients and acts as a fluid vehicle for transferring spermatozoa. This results in fewer copulations leading to a successful fertilization especially since the male has no copulatory organs. However, female birds are able to retain sperm in glandular regions of the uterovaginal junction, which are slowly released, explaining their ability to maintain fertilizing sperm for long periods.
The breeding behaviour and stimuli needed for each species is sufficiently different to make generalization dangerous for it may mislead aviculturists. Some birds will breed readily in captivity, while others possibly of the same species, resist even most persistent encouragement. In between, there are many degrees of what might be termed "breedability".
Reproduction in birds is discontinuous and is triggered by a complex repertoire of behaviour patterns and environmental stimuli. Important factors are; temperature and humidity (thermal), calls and behaviour of mate and other con-specifics in the immediate area (auditory), territory and nest site (visual), nest and allopreening (tactile), food and energy (gustatory) and light acting by induction (photic), Little research has examined these parameters and their role in parrot breeding.
The more resistant species to breed such as Yellow-Napped and Orange-Winged Amazons may just not like the management systems under which they are presently kept and would breed better under a different set of circumstances. The challenge is to keep modifying their management until the optimum conditions contusive to breeding are found. This may include more colony type of housing with more chances to defend territories to the opposite, more privacy in very quiet environments.
Amazons have a higher degree of infertility than macaws or cockatoos. Obesity may be one reason for this higher level of infertility but I don't think its the major one. The defense of territory is perhaps another key component in stimulating reproduction in male amazons. Flocking the birds during the non-breeding season is being used by several leading US breeders. Also visual barriers in between cages are removed after the breeding season until the commencement of another cycle the following spring. Timing is important so that the stimulatory behaviour of other birds does not preoccupy the male.
Diet and Feeding
Generally speaking, psittacines are omnivorous. Much of their daily activity in the wild is involved in the procuring of food, which offers limitless opportunity for flying exercise. Budgerigars, for example, are know to have a feeding range of 100 square kilometres. Restricted flight and ease of obtaining food make energy considerations important in evaluating captive diets. Thus the concern of captive feeding of psittacines is not to reproduce what is available in the wild but to develop a practical diet that provides for the biological requirements under conditions of lower caloric expenditures.
Years ago diseases directly and indirectly caused by dietary deficiency were very common in captive birds. The widespread use of supplements and now formulated diets, at least by breeders, has significantly reduced problems relating to diet. Cases of obesity are still being seen especially if sunflower, safflower peanuts or other high fat nuts are given (these oil seeds contain about 50% fat in the kernel). Eliminating oil-seeds has the advantage of encouraging sampling of a greater variety of foods offered and hopefully result in a better-balanced diet. "Bird seed" is notoriously deficient in many minerals and vitamins and also contains protein of lower biological value. Many of the amazons that I have bought from pet owners and other breeders were obese, even though some were on "pellets mixed with some seeds and fruits and vegetables". If these "pellets" are supposed to replace cafeteria style feeding why do these people still add sunflower to the birds diet?
Psittacines are intelligent, active animals but using food to keep them occupied i.e. as a toy is in my opinion a waste of resources and may not even be nutritious. Cafeteria style feeding a variety of food such as a little of everything e.g seeds, pellets, fruits and vegetables and bean/rice mixes is expensive, time consuming, messy, and may introduce pathogenic bacteria or fungi to the bird. Contrary to popular opinion it may not be providing the level of nutrition people think it does as the birds are selecting their favorite food. People falsely believe that feeding fruits, veges, pulses etc. is more natural than a uniform formulated diet. Yet a formulated diet can contain these same foods only that it is formed into a uniform pellet or extruded into a granule. Also when we look at what parrots eat in the wild, it is not sweet high moisture fruits or vegetables. These are domestically grown and genetically altered for human taste and provide very variable nutritional value. They do provide an excellent vehicle for supplements, which are required by birds eating such a variety of pseudo natural (for an exotic bird) food. Analysis of bean/rice mixes confirms that they are deficient in calcium and many other important nutrients thus must be supplemented.
When I was in the Amazon rainforest (southern Colombia) in 1986, at an Earthwatch research camp, I collected and tasted some of the favorite fig and palm nuts of the macaws and amazons in the area. They were bitter and sour but the birds loved them. It was litterly raining broken pieces of these nuts under a tree that a group of Scarlet Macaws were eating from. Parrots are seed predators because they destroy the seeds of these trees. Evolutionary pressure is on the trees to produce tanins and even toxins to limit the feeding on their nuts. Regardless of this many species of parrots still only eat a limited variety of these nuts, flying with their parents to seek out these trees and learn what to eat. Thus the truly natural feeding of many parrots in the wild is more monotonous than people think and is far from the equally learned behaviour of cafeteria style feeding many of us do to these birds in captivity. The easiest birds to switch onto a formulated diet are recently imported parrots as they have not yet developed a taste for the sweet domestically grown fruits and vegetables. Likewise the hardest birds to get to eat a formulated diet are those which have been eating human food from the table. Please don't misunderstand me, I am not saying we should not feed fruits, veges etc. to individual pet birds. Pampering your pet bird and watching it derive pleasure from its food is one of the pleasures in having a pet. But aviculturists who must optimize cost, their time, and most importantly nutrition, need to understand all aspects of feeding philosophy.
Some interesting recent research has found that when the actual food being eaten on a fruit/vege/seed style diet is determined and analyzed (by collecting all the wasted food and subtracting it from the food fed) it was found that the birds ate a richer diet than had been previously thought. If parrots prefer to eat a diet with twelve per cent fat, and do not get obese on such a diet, why do so many pellets on the market contain only three to four per cent fat? Some companies who sell these products even advise the use of fruits, vegetables or seeds in addition to their product. Ask the manufacturer if they feed their research birds their diet totally or with the addition of seeds or nuts to increase fat levels.
Some people fear the birds may get bored with a formulated diet but long term feeding studies are showing this to be false as there is no increase in feather picking or fighting associated with these diets. To stimulate the psychological needs of parrots rather give lots of tree branches, pine cones, rawhide bones and toys. At HARI we did a controlled feeding comparison where 80 of our mature non-breeding pairs (presently we have 280 pairs of mostly medium to large sized psittacines) were split into two equal groups of species and pairs. One group received only our Tropican Parrot Granules and the other group the same but with an additional bowl of "soft food" eg. diced apple, orange, fresh corn, cooked beans and rice. Well after a whole breeding season we had more pairs commence egg laying on just the Granules (12/40) than in the other group that also received the "soft-food" (9/40) but the difference was not statistically significant. What this does indicate is that the use of "soft-food" does not significantly increase the reproduction of our mostly imported parrots when a good formulated diet is used. In fact in many aviaries breeding has improved with the use of formulated diets.
Amazons are a unique group of pet quality parrots who will always be in demand.
By the end of 1993, imported amazons for unrelated breeding stock will not be available for aviculturists to work with. To be a successful amazon breeder modern avicultural techniques must be utilized including safe, surgical sexing of birds, formulated diets or supplements, disease prevention using screening tests, vaccines for Pacheco's and tetracyclines against psittacosis, efficient safe housing, banding and micro-chip identification, and computer assisted record keeping of breeding stock. Now is the time for us to work together to set up professionally managed stud books of these parrots and ensure their survival into the next generation.
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