Why Did My Bird Lay an Egg? Finding
an egg on the bottom of a
bird's cage is a very surprising event for any bird owner. The surprise
is even greater if the bird does not have a mate and the bird's name is John! Breeders and pet shops usually try to determine gender before selling birds based on visual clues, behavior traits or bone structure
typical of male or
female cockatiels. These methods are not always accurate. Your bird , who was
incorrectly identified
as being a male, now lays an egg, providing proof as accurate as any DNA lab test,
that he, is really a female. Now for the even bigger question, why did John, (who
has now been renamed Joan,) start laying eggs without a mate?
There are a few
reasons including the fact that female
cockatiels are notorious egg layers. Other reasons are based on the
breeding behaviors and needs of cockatiels living in the wild. 1. A
compatible mate has been found and cockatiels often mate for life. 2. For wild
cockatiels, egg laying and
breeding are seasonal activities that only occur during the Spring and Summer
months. Several changes in nature stimulate the breeding activities of wild
birds. The primary influence is an increase in daylight hours during these
months. The climate is also warmer with more rain, and food is more plentiful. 3. Wild cockatiels
build nests inside of hollow trees, as in
the above photo to the left. These same factors influence egg
laying and breeding in our pet cockatiels as well.
John laid an egg because something in the
environment stimulated her breeding hormones and 1 or more of
the following conditions exists.
- The bird perceives a human, toy or image in a mirror to be a mate and she
has bonded strongly with the human or object of her affection.
- Indoor, environmental conditions are
favorable for reproduction all year long.
- Exposure to increased daylight hours because of long hours of artificial, indoor
lighting.
- An abundance of food, water and opportunities to bath are all year long.
- The bird has been hanging out in dark, cozy corners.
- Petting a bird on the back, stomach or under the wings. (where ovary is
located)
Egg
Laying Process: This is a very brief description of a female cockatiel's reproductive system. Adult, female parrots have only 1 ovary and 1
oviduct located on the left side of their body,
under the "elbow" of the wing. Although females are born with 2
ovaries and 2 oviducts, the other ones gradually recede as a bird approaches
breeding age. When
females are sexually mature and something in the environment stimulates
breeding hormones, hens will ovulate and start producing eggs. The yolk of the
egg develops first in the follicle of the ovary. The egg then passes on into the
oviduct, a long, muscular tube that has 5 sections, each one performing a
specific function. All of the other stages of development take
place in the oviduct, where other components
of the egg are added, including albumin and membranes. If a male is present and a successful mating has taken place,
eggs will be fertilized
in the oviduct as well. Females can store sperm in their bodies for up to 15 days,
making it possible for 1 entire clutch of eggs to be fertilized from 1
successful mating.
After fertilization, the egg then moves into the 5th and last part of
the oviduct, the uterus or shell gland. This is where the egg will spend the most time,
from 20-26
hours. While in the uterus, a watery solution will be added to the egg,
increasing the weight of the albumen. The
actual shell itself, which is composed of about 95% calcium carbonate crystals,
will also be formed around the bare egg in the uterus. The egg then passes
into the cloaca and vent until it is laid by the hen. The process of egg laying, from
ovary, (fertilization if male present), to development of shell to egg laying
takes about 2-3 days. If your single female cockatiel lays 1 egg, more
will be on the way. You can expect your female to lay 1 egg about every 48 hours
(2 days). until a clutch of 2-8 eggs is laid. Cockatiels and other parrots
are "indeterminate" egg layers. This means parrots do not lay a
specific number of eggs. If an egg is lost, broken or removed, they will replace it by laying an another egg.
Signs of Egg Laying
Females getting ready to lay eggs will feel heavier, weigh more and their lower
abdomen near the vent may feel firmer and look larger. When producing an egg, females will also start drinking much more water
because eggs are made up of so much water. Chewing activity will also increase, as
females start to shred more paper, perches, wood, toys etc. in preparation of a
nest Females may also become very protective of their cage, backing up
into a corner, chirping softly. Prior to and during the egg laying process,
the female will have very large, loose and odorous droppings. This is also
normal.
Droppings are retained in the cloaca and they are eliminated by the
female in the morning.
What
to do When Eggs are Laid:
Do NOT remove eggs from the cage. You can place the eggs on top of a
non-looped wash
cloth on the bottom of the cage, inside of a little basket, box or other container that has been lined with white paper towels. This will make
your single bird more comfortable and it will prevent the eggs from rolling around. If
an egg breaks or your bird starts pecking at them, remove the eggs and replace
them with white
marbles or wooden dummy eggs. Clean the area thoroughly to prevent bacteria from growing.
Allow your single cockatiel to nest (sit) on the eggs for 21-30 days. Cockatiels
and other parrots are "indeterminate" egg layers. This means
that the species does not lay a set number of eggs. If 1 egg is lost,
broken or removed, a cockatiel will just replace it by laying another egg.
If you remove the eggs, your bird will go right into another breeding cycle and
start laying more eggs. This will lead to chronic egg laying. Sometimes
cockatiels wait until a few eggs are laid before they begin nesting on them. So
don't throw out eggs if your bird is initially ignoring them.
What Stops Egg Laying?: The hormone prolactin is needed to stop the
egg laying cycle in a female cockatiel. When the first egg is laid, her level of
prolactin is low. The level will increase with each additional egg laid and the
amount of time she nests on the eggs. (Source: Facts on Hormones: Exotic
Bird Report, Psittacine Research, Univ. of Calif. Vol 2, Number 3.)The
University of California also reported that clutch size is influenced by hormones and
that clutch size can be controlled to a certain extent. If one egg is removed
from the female' s nest, 1 additional egg will be laid, increasing the clutch
size. If 1 additional egg is placed in the nest each time the female lays
an egg, clutch size is reduced by 1 egg. (Source: Facts on Hormones: Exotic Bird Report, Psittacine Research, Univ. of Calif. Vol 2, Number 3.)
Nesting Phase Care: Nesting on eggs is both physically and
psychologically stressful for your bird and any type of stress impairs the
immune system. Sometimes females that are nesting on eggs are
reluctant to move out of the nest to eat food, drink water and exercise. Keep an
extra set of food and water dishes close to your bird. Females that are laying eggs will
also lose calcium. Provide plenty of extra calcium in her diet from
fresh, dark green vegetables such as kale, cilantro, parsley, beet greens, turnip greens, endive, chard, mustard greens, watercress, broccoli leaves and stalks.
Also offer her bright orange foods, like baked yams, sweet potatoes and
carrots, that are rich in Vitamin A to boost her immune system and high protein
foods like scrambled eggs. Offer her other
calcium and vitamin A rich foods as listed on this page Healthy
Table Foods and this page Table
Foods. If your bird is not eating pellets, make sure she has access to full spectrum
UVA/UVB lighting, 15 minutes each day from a Zoo Med or another brand of full spectrum light bulb. Birds
that are not eating pellets need this type of lighting in order to metabolize
calcium. It's normal for your bird to be more
aggressive with your during while nesting. She'd doing her job and protecting
her nest. When the eggs are eventually removed after 21 days, the aggressive
behavior subside.
Chronic Egg Laying and Health Problems Cockatiels living in the
wild only produce 1 or 2 clutches of eggs each year. More than 2 clutches
would be considered unnatural. Chronic egg laying in pet cockatiels is described as laying more than 2 clutches of eggs per
year.
The stress and physical demands of excessive egg laying include some of the following health problems.
- Malnutrition.
- Calcium deficiencies
- Seizures, low calcium
- Brittle Bones, low calcium
- Weight loss.
- Poor health in general.
- Poor feather condition.
- Feather loss or dermatitis around vent.
- General muscle weakness.
- Reproductive Diseases.
- Abnormally formed eggs.
- Poor muscle tone of oviduct or uterus.
- Prolapsed cloaca or uterus.
- Egg impactions in oviduct.
- Egg Binding.
- Other reproductive ruptures, infections and disorders.
- Sudden death.
Preventing Egg Laying: Avian veterinarians usually consider it safe for
a healthy, well nourished, pet cockatiel to lay 2
clutches of eggs a year. Females that lay more than 2 clutches a year are
considered chronic egg layers. In most cases, chronic egg layers will seem
healthy for years but eventually they will suffer from malnutrition and other
serious to life threatening health problems because of the progressive stress
and physical demands associated with egg laying. Egg laying in excess of 2
clutches a year should be discouraged because it compromises a female's general
health. Once a female
starts laying egg, all future egg laying is influenced and controlled by
hormones. By interrupting, changing and removing the environmental stimuli that
cause a hormonal, egg laying cycle, future egg laying can be prevented.
Environmental adjustments should create undesirable breeding conditions, just
the opposite of what optimum conditions are for cockatiels breeding in the wild.
Modifying your Bird's Environment: so it feels less secure and reducing the
number of daylight hours your bird is exposed are often very effective in
preventing or stopping chronic egg laying. Birds will not set
up nest and start producing eggs if the site they have chosen feels insecure. Re-arrange, switch and move perches, feeding dishes and toys or
replacing them with new items that are a different size, color, texture or
shape. Other changes that can make the cage feel less suitable for nesting
include moving the cage to another area side of the room or moving cage into a completely different
room. Putting bird your bird into an entirely different looking cage in a
different room is even better. The more drastic the change, the more effect it
will have on preventing egg laying. Since exposure to daylight has a
strong influence on breeding hormones, reduce the amount of daylight hours that
your bird is exposed to so the environment resembles Winter, non-breeding
months. Reduce daylight exposure to 10 hours a day and keep the cage covered for 14 hours each
night in a very dark, quiet room, for 2 weeks. If this doesn't help, reduce your
bird's exposure to daylight to 8 hours a day Cover the cage so your bird is in darkness for 16 hours for 2 weeks. Avoid
giving your bird baths, water misting or soft foods during the 2 week period. After
2 weeks resume normal bathing and feeding routines. Note:
Re-arranging, moving the cage and reducing light should all be done at
the same time. Reducing light alone may encourage egg
laying by making the cage seem like a nestbox.
Dark, Cozy Corners Effect both Females and Males: The
presence of an acceptable nesting spot always encourages breeding behavior.
Both female and male birds will seek out dark corners. Females will lay eggs and
males will become very territorial and aggressive, often attacking and biting
you to protect the spot they have found. The
space in-between the bottle and microwave, in the photo to the left is a good
example of the type of area that encourages egg laying and breeding behavior, If you notice your bird investigating dark, enclosed areas like cabinets, open bureau drawers,
the top of closets, the inside of shoes,
socks etc. don't allow it. Close, block or cover the "entrance"
because your bird is probably looking for a place to
lay eggs. Cockatiels do not need an actual nest to lay eggs in. They just need a
cozy, little, out of the way corner, like the one the bird in this picture has
found. Sleeping tents, huts and birdie beds that are sold in stores also
provide a place for egg laying so avoid using them with cockatiels as well.
Avoid petting your bird on the back,
stomach or under the wings because that's where a female's ovary and a male's
testicles are located. When you
show your bird affection in these areas, you're stimulating her ovary or
his testicles. Last but not least, remove any cage mirrors that your bird seems overly attached to and toys that
she/he may use for masturbating.
Hormones & Surgery: If your
bird continues to lay more than 2 clutches of eggs per year despite all of
the measures presented, take her to an avian veterinarian. Prescription, hormone therapy is available
that may help your bird. Another method suggested, (when all other methods fail
and when the hen is still in good health), is to allow the female to raise 1 clutch of
chicks. This may end chronic egg laying. As a last resort, an avian vet
may recommend that a chronic egg layer have a hysterectomy to prevent egg
laying. An avian hysterectomy is the removal of just the 1 oviduct, not the
ovary. Most of the egg's development takes place in the oviduct and the ovary is
located near a very large artery which would make the procedure too risky.
Click Here to read about Egg Binding. It may save your bird's life.
