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ORIGINAL
BOOK REVIEW
by
Dr. Rainer R.
Erhardt
"Well, there is help on
the horizon and
anyone seriously
interested in color
genetics should take
a look at Linda
Rubin's book:
COCKATIEL G ENETICS
MADE EASY!
Though this book is
primarily directed to
breeders of cockatiel
mutations, there is
enough information in
this volume to teach
anyone the secrets of
dealing with
recessive, sex-linked,
and dominant
mutations..."
ACBM, Vol. 65, No.12
CLICK TO READ THE
REST OF THE
REVIEW!
112 pages, 15 chapters,
glossary & more!

NEW MUTATIONS

SPEAKER PAPER

COCKATIEL HUSBANDRY: BREEDING PROGRAMS FOR Y2K
COPYRIGHT © 2000 BY LINDA S. RUBIN
A paper presented to the 2000 Canadian Parrot Symposium East in Toronto, Canada


Aviculturists have been accustomed to working with cockatiels in captivity for many decades as
their "bread and butter" birds, offering hand-fed tame babies, breeding pairs, and top
exhibition stock for sale, all of which has led to an increased popularity of the species over
time. Today, the cockatiel is the number two pet bird in over 6 million US households.
Interestingly, not everyone who attempts to raise cockatiels can successfully reproduce them
and newcomers especially have difficulty. What is responsible for the cockatiels continued
popularity ranges from new breeding techniques learned over the years, to the dramatic
appearance of fascinating new color mutations which has sparked a collective interest in both
newcomers and seasoned breeders alike. Husbandry techniques gathered from avian
research studies have benefited cockatiel breeders by directly improving their breeding studs
or increasing their rate of reproduction. In addition, newer manufactured products ranging from
prepared hand-feeding formulas suitable to the cockatiels' sensitive digestive system, to
brooders and other equipment, have been of tremendous aid to breeding success.

Rarer color mutations such as the Yellow-cheek, Pastel-face, Dominant Silvers, and the new
Suffused Yellows and their myriad combinations are impacting Cockatiel circles both on and off
the show-bench at a challenging rate. The formerly known 'rares' of yesterday are now
increasingly spotted at bird fairs, formally inscribed within show classifications, and currently
rooted throughout classified advertisements, with a new list of contemporary mutations that
continue to escalate. No longer are breeders confined to a world of a few simple sex-linked or
autosomal recessive mutations. Now, the art of producing and combining such color
combinations requires deliberate forethought and planning, and a better understanding of
color genetics and color pigmentation to properly identify and classify new colors.
Controlled versus Colony Breeding.



If the object is to produce a quantity of young during the breeding season, without concern for
superior quality of individuals, or for specific color mutations, then colony breeding is a good
method of producing an abundance of offspring. Experienced cockatiels make good parents
and have been known to feed their own and even other pairs' young. Eager parents, both
cocks and hens, have been seen diving into their own or their neighbors' nest boxes to satisfy
the hungry cries of chicks that have been left temporarily unattended. While one explanation to
attending to others' young might include the increased levels of certain hormones, learned
behavior through trial and error to establish good parenting skills must also be credited.

Additionally, some pairs seem to be better parents even on a first nest, and so possibly a
genetic component has been inherited as well, whether they are merely feeding out their own
or another pairs' young. To plan a successful colony, it is best to expose birds to prospective
mates prior to the breeding season in order to enhance the formation of pair bonds, or else
additional time must be factored in for birds to pair off at the start of the season. Any extra
birds that remain unmated should be removed in order to maintain harmony within the group.

Pairs that are introduced prior to the breeding season will more easily reestablish their bonds
and require less time to go to nest and produce eggs. Although most pairs do form strong
bonds, it is not outside the realm of possibility for a chance indiscretion to occur which the
aviculturist may, or may never, witness. Therefore, it is impossible to guarantee a pedigree
card when using the colony system even if the breeder is convinced of a pair's "faithfulness."

When using the colony system, it is essential to provide enough space so pairs won't be
overcrowded in the flight. Ample room should prevent squabbling over nest boxes, perch
space, or other established territories. The aviculturist should plan ahead, calculating how
much extra room will be necessary to include the number of offspring produced who will
eventually fly the nest.

A number of additional nest boxes should be provided over the number of cockatiels paired.
This will offer birds some choice and keep fighting over boxes at a minimum. If the boxes are
attached inside the flight, the top flat surface can become a good mating stand allowing the
hen to maintain her balance while the cock is standing on her back. Nest boxes hung outside
of the aviary provides the advantage of easy nest inspection without intrusion or disruption to
the colony. Whether nest boxes are hung inside or outside the flight, all perches must be
securely fastened for firm footholds so that effective fertilization takes place.

Nest boxes should be removed after two rounds of young are raised or no more than ten to
twelve chicks per pair. If pairs continue to have access to nest boxes they will continue to
breed and produce additional clutches of eggs, often to the detriment of the hen who will be
robbed of important calcium stores. Continuous breeding and egg production will only rob
pairs of their breeding stamina, making them ineffective parents, and burning them out as
breeders at a premature age. Finally, as young chicks mature, they will be encouraged to start
breeding before they are developmentally prepared to do so or ready to effectively raise their
own young.

Controlled breeding, housing one pair of cockatiels per aviary or pen, is the preferred method
of raising cockatiels if the aviculturist is intent on raising quality over quantity; when breeding
for specific color mutations; and when attempting to produce birds for exhibition. Controlled
breeding is an absolute necessity to guaranteeing proof of parentage and pedigree cards for
offspring produced. Other advantages include the ability to document important data or
information on specific individuals or pairs, and more control over the breeding cycle such as
accurate record keeping and banding of offspring from known parentage. The major
disadvantage to individual cage breeding is the increased maintenance time in servicing
additional aviaries or the need for extra space required to house additional aviaries or
individual pens.

Smaller collections utilizing controlled breeding methods may permanently house established
pairs together. However, the majority of breeders with larger flocks maintain their birds in large
resting flights, and possibly adolescent and nursery flights for younger birds so they need not
compete with adults over food and territory. In the United States, aviculturists predominantly
separate the sexes by housing cocks and hens in separate resting flights. The aim is to
maintain control over birds so they may be repaired to mates of the aviculturist's choosing,
rather than to previous bonded mates. However, sometimes bonds are so strong between a
pair that a new mate will not always be accepted, although this is in the minority, especially
when the original mate is within site or earshot of its call. Cockatiel pair bonds will often
strengthen when they are permitted to live together in resting flights. Therefore, in order to
encourage an individual to be more receptive to a new partner, established pairs are split up
during the resting season then eventually repaired to new partners at the commencement of
breeding season. The author has tried housing established pairs together in resting flights and
found older pairs which have already raised young together to maintain exceptionally strong
pair bonds as evidenced by mutual preening (allopreening), perching and sitting together, and
sometimes feeding together, even in large spacious flights. In general, cockatiels in a
controlled breeding environment will pair with a new partner and produce eggs within two to
three weeks of introduction, provided all the necessary elements for the commencement of
breeding are provided.

Most breeders have their own preferences or favorite foods that they provide for their flock.
However, today, a number of manufacturers have increased their product lines to include
brands suited for cockatiels based on their own nutritional research studies. Many breeders
are also aware that cockatiels live longer on a low-fat diet and therefore offer a basic diet that
keep fats to a minimum.

Feed: Obtain a high grade, well-cleaned cockatiel mix that contains canary seed, and white
millet, with a variety of other seeds in moderation, and fortified with additional vitamins and
minerals. Select a brand that is low in fat for resting birds, preferably near 4-5% fat. Breeding
pairs, however, need to be offered a diet higher in both fat and protein content for the required
nutrients to form eggs, develop embryos, and nourish chicks as they grow.

If available, it may be preferable to select a pelleted or extruded diet instead of seed. Pelleted
products are an excellent, optimum method of feeding for both breeding and resting birds.
Each pellet contains complete nutrients, there are no seed husks remaining, and pellets and
extruded diets are thought to be the most nutritionally complete diets as "best known at this
time." (Update: Never feed solely pellets or extruded diets alone; include seeds and fresh veggies as well).

It is important to introduce pellets according to the manufacturer's directions, as instructions do
vary. There are two methods that are the most common. The first method of converting
cockatiels to a pelleted or extruded diet involves mixing the pellets 50/50 with the existing seed
mix, and increasing the amount of pellets over the next two weeks until only pellets remain. The
second method is to offer only the pellets during the day, but replacing the seed in the evening
for birds to feed so they won't go to sleep hungry. Each day the pellets are offered in this
manner (some instructions do vary). It is important in both instances, however, to keep a close
eye on birds so that they do not starve to death. Cockatiels are stubborn birds and creatures
of habit and will often times literally starve to death rather than attempt something new or
unfamiliar. Therefore, use common sense, monitor birds (ideally weigh them each morning) to
see they are not losing too much weight in the process. If necessary, return to the bird's
normal food and try again another time once weight has stabilized.

Another point to be aware of when feeding pelleted or extruded diets is the change in the color
of the birds' droppings. Also, because there is little moisture in the pellets, birds tend to drink
more water than if on an otherwise all-seed diet. One initial research study at a well-known
university found that breeding cockatiels flourished with a pellet containing 20% protein,
producing healthy, robust chicks. It was also learned that resting cockatiels required a lower
protein level e.g., 15% when not breeding, as too high a protein level could cause damage to
certain organs.

Millet Spray, Seed Treats: All cockatiels adore spray millet and the author feeds it to
breeders and young daily, and resting birds each week. Millet spray is especially tempting to
sick birds that often won't eat anything else, and it is a great advantage when weaning young
chicks onto hard seed, pellets, or other foods. Spray millet is especially useful for new birds
who, when acquired as pets, are often too frightened to move for three days, let alone eat!
Just hang a spray within easy reach for positive results. There are also many other treat type
foods on the market that can be fed in moderation. If such foods are packing on extra weight,
cut back until birds are back to normal.

Vitamins and Minerals: If one chooses not to feed fortified products, vitamins should be
added to the diet. During the breeding season, a daily offering of soft food such as a cooked
corn/rice/bean mix, or egg food (provided it is replaced or removed after several hours),
should be lightly salted with a powdered avian multi-vitamin/mineral supplement containing
vitamins A and D3. Breeders require vitamins on a daily basis and resting birds several times
each week. Cuttlebone or mineral block, a vital source of calcium for both resting and
egg-laying birds, must also be provided. Breeders also sometimes provide soluble oyster shell,
or chicken egg shells roasted at 350 degrees for 45 minutes. Be certain to wash the shells
before baking to remove any possible Salmonella bacteria.

Water: Provide clean, fresh water, on a DAILY basis, in clean, disinfected vessels. Water is
vital to the metabolism of nutrients and necessary to maintain good health. Be certain to
thoroughly disinfect the water vessels using only clean sanitary instruments not used for other
birds. The author uses paper towels and dishwashing liquid each day to clean and rinse the
vessels; and replaces all vessels every week with an alternate clean set while used vessels are
scrubbed, disinfected, then run through the dishwasher and stored for future use.
Interestingly, a research study entitled Cockatiel Research at the University of California at
Davis (Roudybush, 1985) found that fledgling cockatiels required the provision of water in
order to be successfully weaned, otherwise weaning was delayed.

Fresh Produce: A variety of fresh vegetables should be offered two to three times per week
minimum, and daily to breeding, weaning, and young birds to keep them trained in the habit of
eating a variety of produce. Dark green, leafy vegetables supply necessary carotene
(converted by the liver into vitamin A) for example: dandelion greens (and flower), collard
greens, carrot tops, and kale, rank highest in vitamin A. Other vegetables containing a variety
of vitamins and minerals include: broccoli, mustard greens, fresh peas, string beans, chicory,
parsley, and watercress, are all favored. Lettuce and the cabbage family contain little food
value and are next to useless. Yellow/orange vegetables high in carotene (a precursor to
vitamin A) include: raw carrots, and cooked vegetables such as yams, squash, sweet potato,
and pumpkin. In a pinch frozen vegetables (e.g., corn, peas, carrots, and beans), can be
served cooked. As with other parrots, avoid avocado and eggplant which are toxic. Fresh fruit,
such as apple, orange, cut grapes, banana, and especially berries in season such as
cranberries and blueberries, and pomegranates, etc. are well accepted provided birds are
exposed to all these foods while young. Cherry pits are toxic and should never be fed.
Cockatiels, unlike other members of the parrot family are not big fruit eaters, instead preferring
fresh greens and other vegetables. Yet, fruit can become an additional part of the diet if birds
are patiently trained to eat them while young.

Table Foods: Breeders with smaller collections or just a few birds may be able to provide
some occasional table foods. Simple carbohydrates such as fruits and vegetables, or complex
carbohydrates if fed in moderation including: pastas, noodles, macaroni, brown rice, spaghetti,
etc. are good when offered without the sauce. Whole grain foods such as oatmeal, sugarless
cereals, pancakes, and similar breakfast foods are all good. Proteins such as cheese,
scrambled or 20-minute hard-boiled eggs, small pieces of well cooked chicken or meat, can all
boost the diet. As a rule of thumb, think of your cockatiel as a health food nut, never offer
foods containing high fats, sugar, chocolate (it's toxic to birds), alcohol, or caffeine, all of which
can cause harm or toxicity. Cockatiels must be exposed to dietary items on a regular basis to
develop good eating habits. This means feeding such foods from as early an age as possible
and never giving up until your bird(s) accept these foods. In time, they will. Never give up!


Breeding/Environmental Conditions: Breeding cockatiels require five prerequisites for
reproduction: 1) optimum nutrition; 2) increased daylight (photolight period); 3) increased
humidity; 4) an acceptable mate; and 5) an adequate nesting site. Increased or normal room
temperatures can mimic the breeding season, although many breeders have been successful
with lower temperatures as long as they remain constant and without fluctuation. Increased
humidity via open water drinking bowls, or spray baths, signal the onset of the rainy season
which wild pairs rely upon to provide the "milky stage" seeds with which they feed their young.
Increased temperature and humidity for birds raised in outdoor aviaries will signal the start of
the breeding season. Breeders who raise their birds indoors have an advantage of being able
to control the environment, and hence the breeding season, through the provision of artificial
light and extra humidity. As non seasonal breeders, cockatiels can be bred anytime of the
year, as long as conditions such as the number of daylight hours are met. The photolight
period may be aided by installing an automatic light timer and dimmer to indoor aviaries to
provide a few extra hours of added light for parents to finish feeding hungry babies. Lights
during the breeding season in the author's indoor aviary are not extended beyond 10:00 PM at
night.

Humidity levels are critical to hatching eggs. If humidity is too low, chicks stick to the egg
membrane and cannot rotate inside the egg to pip their way out. Conversely, too much
humidity can drown a chick inside the egg. Cockatiels generally control humidity levels by
sitting in an open water bowl, or bath, and returning dripping wet to the nest to sit the eggs
days prior to their hatching. When necessary, either spray misting with clean water that is room
temperature, in an atomizer used only for that purpose, or the provision of a humidifier may be
helpful.

Pair Bonding: Cockatiels should never be set up to breed unless they are in breeding
condition, which equates to top, physical health. Most reputable breeders will not set up a pair
of birds until they are a minimum of twelve months old, more often at 18 months or more to
allow for full maturity and good parenting skills. Breeding birds are healthy, filled with energy
and vitality, and usually engage in behaviors such as chewing or burrowing under cage floor
newspaper or other materials. Other behaviors include seeking suitable nesting sites, and
actively courting a mate. Hens will emit a soft repetitive warble while crouching low on the
perch. Cocks will engage in ritual behaviors e.g., mutual preening, possible courtship feeding,
and attempt to mount the hen. While most cockatiels will accept a mate of your choosing, on
rare occasion a bird may reject a prospective partner and even behave aggressively,
especially if it is already pair-bonded to another bird that is within sight and sound. It is best to
re-pair such birds or allow them to rest until they return to breeding condition. In recent years,
breeders who raise birds for exhibition and wish their birds to pair with specific mates have
found that, if they housed the pair of birds together for six to eight weeks while young, the pair
would go to nest more readily when re-paired at the commencement of the breeding season.
Assuming all five requirements are met as listed above, including satisfactory diet (e.g., a daily
soft food mix such as corn/rice/beans dusted with vitamins, plenty of green food, and a
nutritious daily breeder diet); extended photo light period; proper humidity levels; and an
accepted mate; all that is required is to provide an adequate nesting site.

Breeding Pens and Nest Boxes: Cockatiels are known to reproduce quite well in pens
measuring as little as four foot in length, by two and a half foot high, and two feet deep,
providing pairs are rested in larger accommodations following the breeding season. Although
some fanciers have had success utilizing smaller enclosures, increased problems such as
feather picking, squabbling over space, etc. can result. If one has the space, ideally, individual
flights should be provided housing one pair per flight for optimum results. However, care must
be taken that in long flights, birds do not fly at break neck speed against a wall which could
have devastating results.

Many fanciers, including the author, still utilize the twelve inch square nest box, although
certainly smaller sizes can be used. The advantage of a larger box allows more space when
raising young, especially if five or six chicks hatch out. Large boxes have the disadvantage of
allowing eggs to roll off or chicks to wander away, especially with inexperienced parents. Some
breeders may wish to use concave blocks for this purpose which will allow pairs to keep the
babies together more easily. However, many breeders add an inch or two of white pine
shavings and allow the hens to eliminate what they do not use. Extra care must be taken that
chicks do not become lost in a mass of shavings unable to return or be retrieved by a parent,
especially by an inexperienced one. Most pairs usually accept a two to two and a half inch nest
entrance hole.

Nest boxes should be thoroughly disinfected at the conclusion of the breeding season and
stored in a clean, dry, area. Breeders utilizing the traditional plywood, pine, or other wooden
boxes should consider replacing them at the end of the season as wood is porous and cannot
be completely disinfected. The author now solely uses aluminum nest boxes that can be
completely disinfected and stored at the end of the breeding season.

Breeding Cycle: Provided all elements are in place (including the prerequisites of extended
light and increased humidity), most pairs will go to nest and produce eggs on an average of
ten to fourteen days after being placed in a breeding pen with an acceptable mate, nest box,
and conditioning diet. Eggs hatch between 18 and 21 days, depending upon when the hen first
begins to sit the clutch. Virgin hens, in particular, may not sit until the appearance of the
second or third egg. DO NOT PREMATURELY OPEN THE EGGS. Allow the hen an extra week
to sit, unless you hear constant peeping and have to provide assistance. If necessary, seek an
experienced breeder to help if you have never assisted a hatching before. Both cocks and
hens share the duties of incubation, feeding and sitting the chicks. In pairs with especially
strong pair bonds, cocks and hens may sit simultaneously, especially through the night.
Otherwise, cocks perch as sentry guard outside the nest box at night.

Chicks hatch out with a sparse covering of yellow down, or in the Whiteface mutations and
their crosses with white down, with eyes closed. Depending upon bloodlines, chicks may be
closed banded between ten days and two weeks of age on average, around the time the eye
slits are opening. Very large exhibition size chicks may have to be banded earlier while smaller
pet quality chicks may have to be banded later. Check the chicks each morning to be certain
the band remains on the leg. The chicks will generally fledge at four to five weeks of age when
they leave the nest box to investigate the pen. They are fully feathered except for their short
tails and are still entirely dependent upon their parents for food. They will learn from their
parents to sample, play with, and pick up food, and attempt to return to the box at night to
sleep until they are fully weaned.

Chicks wean from seven to ten weeks, eight being average, when parent-reared. Handfed
chicks may require from eight to ten weeks, with some individuals weaning later. Always
remember each chick is an individual and will wean, as some research has shown us, when
they are developmentally ready to do so, and not before. Chicks that continue to beg for food
and do not have a full crop should continue to be fed until they fill their crops on their own at
night.

As a general rule, no more than two full clutches, or ten to twelve chicks total, should be
allowed per pair per breeding season. The only exception is the farming out of an additional
clutch to foster parents or assisting pairs by handfeeding young. The conclusion of the
breeding cycle should be followed by a minimum of a six month break in a long resting flight.
Encouraging further nesting will only overburden pairs in the long run, exhausting or
prematurely limiting their reproductive life span. Exceptions might include pulling young for
handfeeding or fostering eggs to other under-accomplished pairs, provided all birds are
healthy. However, it should be realized that an enormous amount of energy and nutrition go
into forming each individual egg and pairs should not be purposely overtaxed, or such birds
and their offspring will pay the price.

While many breeders prefer to handfeed young to obtain tame chicks to resell, it must be
stated that such pairs should be allowed to raise at least one nest of chicks each season, so
that the instinct to feed their young and perform good parenting is preserved and passed on to
their offspring. These youngsters in turn, will mature into good parents who are also capable
parents. If we continue to deny our birds the opportunity to raise their own young, we will
eventually create large gene pools of cockatiels that aren't capable of raising a nest of chicks
on their own.

The genetics of cockatiel color mutations is becoming interesting as it starts to pick up in both
the number of rising new mutations, additional modes of inheritance, as well as developing a
new understanding of color pigmentation. Many of us are now aware that the Tyndall Effect, or
Rayleigh Light Scattering as it is commonly called, may not apply to parrots, including
cockatiels. Groups in Europe and America are starting to re-examine color pigments by looking
at feathers under the microscope. While the average aviculturist does not wish to learn such
terms as eumelanin pigment, schizochroism or argue about the true definition of "dilution," it is
important that we do agree upon terms which have a scientific basis, while being
understandable to breeders. Unfortunately, at this time our newest mutation is being called
either "emerald," or "olive," which is in the author's opinion, most disheartening. For the
moment, I believe (Silver) Suffused Yellow might be a more accurate description although
there is still more that remains to understand this mutation and its unique appearance.

While most of us who work with the new mutation agree that it is an autosomal recessive, it is
still not clear whether the Silver (coloration) is the same autosomal Silver we have been
working with, a cross with the Dominant Silver (owing to an appearance of a skullcap in some
individuals), or even if Fallow has combined as a cross-mutation resulting in the yellow
suffusion which permeates the heavier marked individuals. The question is which pigments are
involved (e.g., eumelanin brown, psittacins, xanthophylls, schizochroic gray)? Undoubtedly, the
future will provide more answers.

A final concern is one that our friends in the Budgerigar Fancy faced some years ago when
attempting to save their pure homozygous Normal Greens which carried no other mutations. It
is now becoming increasingly difficult to find a pure, homozygous Normal Grey cockatiel that is
not split to at least one or more mutations. Why is this important? Because one day we may
discover that pure Normals not only help produce other colors (a treatise could be written of
this subject alone), but that pure Normals, or our original wild type cockatiel, can help to
invigorate our remaining mutation stock. If you have any pure Normal Greys, or can produce a
small group, it would be to your best interest to do so as many exhibitors today are attempting
to locate such Normal stock. You could eventually be one of the few with such birds.

                                                   REFERENCES
Roudybush, Dr. Tom, (1985), American Federation of Aviculture national convention.

Rubin, Linda S. (1997), Cockatiels: Breeding Smart, self-published by Aves Communications, Boston, MA, USA

Rubin, Linda S. (2000), "Cockatiel Husbandry: Progressive Breeding Programs in Y2K," a talk presented at the American
Federation of Aviculture 26th national convention in Los Angeles, California, USA.

ABSTRACT

COLONY BREEDING

CONTROLLED BREEDING

DIETARY REQUIREMENTS

BREEDING HUSBANDRY

NEW MUTATIONS