By Dale R. Thompson and Linda Barber
The successful breeding of exotic birds in captivity has been challenged by the difficulties faced in rearing the young to maturity. During the late 1800’s and early 1900’s, many birds of the order Psittaciformes were first kept in captivity with some success. Early aviculturists became frustrated by the fact that relatively few young birds hatched in captivity survived. They found that captive pairs were poor parents, and attempts at hand-raising the offspring were often futile. It was through the trial-and-error efforts of a few dedicated aviculturists that the groundwork was laid in the proper techniques for successful hand-rearing.
Serious work in this direction was started in the 1970’s. Personnel at the San Diego Zoo in Southern California were among the leaders in advancing the art of hand-rearing and demonstrating its benefits.
REASONS FOR HAND-REARING:
The greatest advantage of hand-rearing lies in the fact that many birds are saved that would otherwise die. Unsuccessful propagation has various causes, ranging from poor incubation to illness in the young. The inability of birds to adapt to captivity and new climatic conditions can also lead to poor incubation and subsequent embryo death. The Eclectus Parrot (Eclectus roratus), a tropical species, may nest in the winter in an adverse colder climate, and incubate without success. Also, some parrots will break and eat their eggs. When these problems arise, the eggs must be removed from the nest and artificially incubated. Brooding problems are also linked to poor adaptation to captivity. Parents may be inconsistent in brooding, resulting in the young dying of exposure. In addition, excitable parents may destroy their chicks if the nest site is disturbed. We remove babies from the nests of breeding pairs who have displayed these types of behavior in the past, or when the young show signs of illness. Those birds that are potentially ill can be observed and treated while being hand-raised.
There are valuable behavioral advantages in hand-raising young parrots. One is the tame and delightful disposition of the baby when weaned. The hand-reared young birds may also make better breeders and parents because they are less stressed by confinement and contact with people. In addition, removal of young soon after hatching sometimes results in the parents returning tot he nest and laying more clutches per year than they normally would. Saving birds and producing birds better adapted to captivity make hand-rearing a worthwhile effort.
Although it is not normal procedure to remove eggs of very young birds on a regular basis, there are times, as explained above, when removal is advantageous. Preferably birds can be left with the parents from ten to twenty-one days, depending on the species. During the early stages of development parent-raised chicks gain weight more rapidly than chicks hatched in the incubator and hand-raised from the first day of age. However, at weaning, hand-reared and parent-reared young are usually of comparable weights.
The ease of hand-rearing a bird is affected by the age of the bird when it is removed from the nest. This is especially true with some of the more difficult species, such as Eclectus Parrots and some species of Cockatoos (Cacatuinae). After hand-rearing over sixty Eclectus we have found nineteen days to be the best age to remove these babies from their parents. We try to avoid very early removal when the birds are the most vulnerable to stress. On the other hand, if removed when feathered, the young birds can be difficult to handle and feed, and weaning becomes more stressful. These birds eventually calm down, but added patience is required on the part of the person caring for them.
The techniques used at Behavioral Study of Birds, Ltd., are offered as guidelines. We work with over sixty species of the Psittaciformes order, mostly the larger species, such as Macaws, Cockatoos, Eclectus, Amazons and African Greys. We have developed techniques based on our own experience and have also used or modified techniques of other successful aviculturists from around the world.
We take many factors into account when arranging the proper set-up f or the care of a bird after it is removed from the nest. Young that are partially parent-reared and removed at an early age are placed in a brooder box at a temperature appropriate to their stage in development. Older birds that are sufficiently feathered are removed from the nest and placed directly into a cardboard box. All hand-reared young are kept in a temperature-controlled room that is maintained between 21 degrees – 27 degrees C (70°-80°F).
One-day-olds are placed in a brooder box and kept there until they have wing feathers and some feathering over the back. This brooder, designed at our facility is a wooden box measuring 61 cm x 31 cm (24in. x 12in.), and 28cm (11 in.) in height, A lid that completely covers the top offers access to the brooder, and there are several 1.5cm (1/2in.) holes at both ends to allow air circulation. There is a 15cm x 36cm (6in. x 14in.)viewing window in the front for observing the baby without disturbance. Air temperature is maintained with a heater controlled by a wafer thermostat. The heater is located in a screened off section at one end of the brooder, which prevents contact by an active baby. Increased humidity can be provided by placing a wide-mouthed container of water without a lid inside the screened-off area. This container should be wide because the humidity is dependent on the amount of water surface area. Surface heat is provided by a thermostatically-controlled heating pad covered with cloth diapers, which mimics blood surface of the parent bird. Both air and surface temperatures are constantly monitored and are adjusted according to the baby’s age and degree of feather development. These temperatures are changed several times during the weeks the baby spends in the brooder box. During the first week, the air temperature is kept at 32.2°2C (90°F) and the surface temperature at 34°-35°C (94°-96°F). The surface temperature is gradually reduced until at the sixth week of age or when feathering is complete over the back and wings; the surface temperature will be approximately 29.4°C (85°F). The surface temperature is more critical to the bird than is the air temperature. During the first ten days over-heating results in dehydration, while under-heating chills the bird and decreases its appetite, resulting in reduced intake of food.
When the bird has sufficient feathers over its back and wings to prevent chilling, it is moved from the brooder box and placed in a cardboard box. The box is warmed by an electrical heating pad placed under it. The inside air temperature of the box should be kept no warmer than 29°C (85°F). The heating pad is removed one to two weeks prior to moving the bird into a cage, where weaning takes place.
The inside floor of both the brooder box and carboard box is lined with cloth diapers. We favor diapers over pine or cedar shavings, as occasionally babies will ingest small pieces of shavings, resulting in blockage of the crop. It is also important to check the diaper or cloth for loose threads or holes to prevent entanglement and damaged limbs. Soiled diapers should be changed after every feeding.
As the baby develops a small hole may be cut in the top of the cardboard box, or the top may be left partially open to allow the young bird to peek out. Gradual exposure of the bird to the outside significantly reduces the stress of moving the bird into a wire cage.
When the bird is fully feathered and standing on its own, it may be moved to a wire cage. To provide the bird with a feeling of security and lessen stress, cloth towels are used to cover most of the cage during the first week; these are then gradually removed as the bird becomes adjusted to the open cage. A perch is placed low in the cage to encourage the bird to climb on it. Because young birds are wobbly on their feet, the perch should be large in diameter (relative to the bird’s foot size) and have a flat surface on top. We keep the birds in these cages until they leave the facility or are placed in flights to be used in our breeding program. If a baby is chosen for used in a breeding program, it is best to place it with its own kind as soon as possible after weaning. Some aviculturists place young birds together prior to weaning; however, if a disease problem is present it may spread to the neighboring birds.
DIET AND FEEDING TECHNIQUES:
There appears to be as many food formulas as there are aviculturists. Most people successfully use one of the many popular formulas or modifications of them. In general, the basis of these formulas consists of a grain, seed, or prepared cereal base to which various other types of foods are added. It is important that the formula used be nutritionally sound, but the additional factors of food consistency, the amount fed, and the frequency of feedings are all important in raising a healthy bird and avoiding digestive disturbances. Selection of these three factors varies according to the species and age of each bird, and whether the bird was partially parent-raised.
Over several years we have experimented with a number of different food formulas. The formula we have experienced the most success with in the many species of Psittaciformes we hand-raise is listed in Table 1. All of the dry ingredients are ground separately, using a hand grinder or blender. After each ingredient is ground, it is placed separately in a sealed plastic container and kept in the freezer. We try to avoid touching the food when preparing ingredients and formula. The consistency of the dry ground ingredients should be fairly coarse. Except for the first few days of feeding, when food is fed watery, large chunks of food can be found in the crops of parent-fed birds. Dry ingredients ground too fine may be a cause of crop impaction. The dry ingredients, along with the vitamins and calcium, are mixed with bottled water to the desired consistency prior to each feeding. The formula is then heated in a microwave oven, and stirred before feeding for even heat distribution. The food is heated to 38°-40°C (100°-105°F); higher temperatures may scald the bird’s crop. Temperatures lower than 38°C (100°F) may cause the young bird to reject the food. The optimum food temperature which stimulates the baby to eat is that at which the parent would feed. We mix only enough formula for one feeding of a group of babies at a time because bacteria can multiply in leftover food and reheating reduces vitamin potency. Any extra food is thrown out.
Aviculturists use a variety of utensils for feeding the formula, such as a spoon, syringe, or soft rubber tube. Spoon-feeding is the most common method because it triggers the feeding response by stimulating the commissures of the beak. Tube-feeding is the method used the least due to the danger of misplacing the tube into the trachea. We use the syringe method because it is easy to measure the amount of food given, and is readily accepted by the baby. With this method the feeding response may be triggered by pressing with the finger and thumb on the commissures of the beak while the palm of the hand is used to steady the bird’s head. Very young birds have soft mouths so it is important to feed on alternate sides of the mouth, as always using the same side may result in curvature of the beak.
For the first few days of life we follow the parents’ method and feed a watered-down version of the same formula through a small syringe (12ml.) while avoiding overfeeding and stretching of the young bird’s crop lining. A baby first entering the nursery is not fed until the crop is completely empty. This is important with all feedings, as old food left in the cop may spoil and not pass through. Extra feedings of warm water may be given if one observes that the previous formula is too thick and is passing through the crop too slowly. After the first few days the bird is fed to the full capacity of its crop at each feeding. Babies up to a week old are usually fed approximately eight feedings per day, determined not by the clock, but when the crop is empty. At five to six weeks of age, the number of feedings is reduced to three per day. During the weaning process, feeding is reduced in the following sequence. The second feeding of the day is eliminated, followed by the first feeding, then the third. At approximately two weeks of age, we switch from a 12ml. syringe with a small tip to a 35ml. catheter-tipped syringe for feeding. This allows us to feed the formula at a coarser consistency.
Weaning a baby is by far the most difficult time in working with the bird. Some birds start to refuse hand-feeding too early, while others prefer formula feeding to eating solid foods on their own. We try to simulate the same procedure in weaning as the parents, and to approximate the time of weaning to the time the babies would normally leave the nest. After fledging the nest, the parent birds reduce the amount of food they feed to their young. The babies then lose weight, enabling easier f light and causing them to be hungry enough to seek food on their own. When weaning begins in our nursery, there is a definite drop in weight which we consider normal. However, weighing the birds daily is of great importance in determining if the bird is losing too much weight and needs supplemental hand feeding.
While reducing feedings a large selection of fresh fruits and vegetables is placed in the cage where it is easily accessible to the bird. Two of the first foods offered are raw corn-on-the cob and hulled sunflower seeds. From hulled sunflower seeds it is easy for the bird to make the transition to seeds with shells. The use of hulled sunflower may reduce weaning time by as much as one to two weeks and also results in lower weight losses during weaning.
It can be a tremendous help in the proper management of each bird to keep records at all stages of development. We take the weight of each baby every morning before its first feeding. A daily record sheet is used to monitor the weight gain or loss from the previous day (figure 1). We also use the record to note amounts of formula and times fed over a twenty-four hour period (figure 2). The general appearance and condition of the birds, such as abnormal feces, poor feeding response, listlessness, etc. is noted. In addition, normal developmental changes, such as when the eyes open and feathers appear, are recorded to establish norms for each species. This enables us to review our records and determine if a particular baby is normal for his age and stage of development.
Proper hygiene is very important in maintaining the health of young birds. The young are particularly susceptible to disease because they lack the fully developed immune system of the adult. We take many precautions to reduce incidence and spread of disease in our nursery. Visitors are kept to a minimum and no one is permitted to enter the nursery wearing clothes that have been in contact with other birds. The nursery staff handles and works with only the nursery birds, and is excluded from other areas in the breeding facility. The staff changes footgear to shoes worn only in the nursery, and they don clean smocks when entering. Before handling anything in the nursery, the staff scrubs their hands with a brush and disinfectant soap for two minutes. The floor, counters, and various other areas such as the refrigerator handles and the microwave oven are cleaned and disinfected daily. All appliances and utensils used in preparation of the food and feeding are scrubbed and then soaked in a chlorhexidine disinfectant after each use. Food is prepared fresh for each meal and fed promptly after heating.
Behavioral Study of Birds has its own staff veterinarian and medical technologist and maintains a diagnostic laboratory. This allows for the testing of birds on a regular basis. Before any bird is brought into the nursery, swabs from the crop and cloaca are cultured to identify the bacteria present. If potential pathogens are found, the bird is treated with appropriate antibiotics (as determined by drug sensitivity testing) to eliminate the pathogens. This reduces the chance of a new bird bringing bacterial disease into the nursery. The birds are then cultured periodically throughout their development to ensure that they remain disease-free. The water supply and food fed to the birds are also cultured periodically to make sure they are free of pathogenic bacteria as well. To prevent the potential spread of disease from bird to bird within the nursery, the birds are kept in individual cages, and the staff disinfects their hands between handling each bird. Although these steps may seem a bit drastic, since these precautions have been implemented the incidence and spread of disease within our nursery has been greatly reduced.
1/2 cup Hulled Sunflower
1/2 cup Raw Shelled Peanuts
1/2 cup Gerber’s High Protein Cereal (a) (apple & orange)
1/2 cup Tune-Up’s Myna Bird Pellets(b) fortified with fruits
(apple, peach, apricot, banana, dates, raisin.)
1/2 cup Purina’s #5045 Monkey Chow(c)
1 teaspoon powdered vitamins (Vionate(d), Avia(e), Super Preen(f)). 1 teaspoon Di Calcium Phosphate(g)
(a) Gerber’s High Protein Cereal, Gerber Products Co., Fremont, Michigan, 49412.
(b) Tune Up’s Myna Bird Pellets, Modern Pet Foods Co., Vernon, Ca. 90058.
(c) Purina’s #5045 Monkey Chow, Ralston Purina Co., St. Louis, Miss. 63188.
(d) Vionate, E.R. Squibb & Sons, Inc., Princeton, N.J. 08540.
(e) Avia, Nutra-Vet Research Corp., Poughkeepsie, N.Y. 12601.
(f) Super Preen, RHB Laboratories Inc., Santa Ana, CA. 92705.
(g) DiCalcium Phosphate, Nitro Prod. Inc., Industry, CA. 91744.
Bates, J., and R.L. Busenbard. 1969. Parrot and Related Birds. T.F.H. Publications, Inc., Jersey City, New Jersey.
Clements, J.F. 1978. Birds of the World: a Checklists. The Two Continents Publishing Group, Ltd., New York.
Forshaw, Joseph M. 1977. Parrots of the World, T.F.H. Pulbications, New Jersey.
Low, Rosemary, 1980. Parrots Their Care and Breeding. Blandford Press Ltd., Poole, Dorset, United Kingdom.
Figure 1. Average weight gains of eight Macaws
2 Hyacinth Macaws, Anodorhynchus hyacinthinus
3 Scarlet Macaws, Ara macao
1 Blue and Gold Macaw, Ara ararauna 1 Military Macaw, Ara militaris
1 Green-wing Macaw, Ara chloroptera
Figure 2. Average amount of formula that is handfed to baby Macaws. Average from eight birds.
(2 Hyacinth Macaws, 1 Blue and Gold Macaw, 3 Scarlet Macaws 1 Military Macaw, 1 Green-wing Macaw)
(*) Number of feedings were reduced at this time.