• If embryos of our cage birds were not so small, we could examine them for possible causes of death.
   

Deformities are often present.

• Such impairment of growth may be due to deficiencies in the yolk which nourishes the embryo
• or improper diet/nourishment in hen when eggs being formed.
• or to hereditary factors.
  • Certain beak deformities have been found to be inherited.
  • A good reason to keep Breeding records!
     
• The embryo may be in the wrong position within the egg.
• Cooling of eggs is less often the cause of D.I.S. than once thought.
• Normal embryos can stand quite a bit of cooling before being injured.
• Milling around of eggs by young of the previous clutch is a common cause for the failure of eggs to hatch.
• Too much moisture in the air prevents the egg from "breathing" normally.
• However - An atmosphere which is too dry will dry out the egg and toughen the membrane
  within the shell and the hatching chick will not be able to pierce it with it's "Egg Tooth".

• The homeland of our budgies, Australia, is a dry continent and it is perhaps not surprising that these birds
  do not prosper in an atmosphere which is too humid.
   
• If the hen feels the eggs need moistening, she will dampen her breast feathers on wet greens if available in her cage or in the water dish/bath.

If the embryos were fully developed when you opened the eggs, the hen isn't having trouble incubating.  

• In fact, if the embryos develop at all, the hen isn't having trouble incubating.  

• An incubation problem would be if the hen didn't sit on her eggs.
   

• or if she let them cool down too much while she is outside the nest for too long, feeding and doing her business etc.  

  • this is where the cock is meant to come into his own and feed the hen while she is sitting.

  • Some Cocks do not take this task as seriously as they should and this is when some problems can occur.
     

• One problem may arise if they hen has a lot of eggs and maybe an odd one will be pushed out from underneath her and get chilled and therefore die. (D.I.S.)
   

• if the base of the Nestbox is too big/spacious for the breed of bird using it

  • - the eggs may become scattered.

  • The neater-sized the base of the Nest box the better the hen prefers it

  • also the Deeper down she is the more secure she feels.

    • She will be less likely to keep jumping in and out if she hears noises/disturbances etc.,

  • If the nest is too spacious, light and not deep enough the hen may not feel secure and not sit
    as tightly on her eggs, as she should.
     

•  - if there is nothing on the base of the Nest box to stop the eggs rolling around i.e. substrate

  • ("Easibed" - a fine wood chip, shavings, peat etc.)

  • Don't use too much bedding tho., cos then the eggs/chicks can get separated semi-buried/buried
    and once again become chilled.

    • Esp. when the chicks very young (before their eyes are open - they are more fragile/vulnerable).
       

•  If the chicks gets separated from the hen, it can die 'cos the hen isn't feeding it and/or it gets chilled

  • esp. if the weather is on the cold-side.

  • If the chick gets chilled then it's metabolism slows right down

  • then it doesn't beg for food

  • nor is it able to digest it's food out of it's crop, cos the digestive tract has slowed right down too.

  • So, it slowly dies from hypothermia.
     

  • All Nestbox bases should have a concave shape (like a saucer) to help prevent the above problems with the eggs rolling away from under the hen.

  • this Base shape helps to keep all the eggs together and under the hen.
     

• In very warm weather the hens poss will "sweat" and not sit tightly enough on their eggs

• In very cold weather the hens may poss. sit too tight

  • Inexperienced first-time young hens may stand on the chicks or sit either too tightly or sporadically allowing the chicks/eggs to chill.

  • Both situations can be detrimental to the development of the developing chicks/Eggs.
     

• Other Hens may go into the Nest and upset the sitting hen and disturb her incubation.

  • They may even chase the hen out and adopt her nest

  • some also kick the eggs out so they can lay their own.
     

• Chicks from previous rounds may also go back in the nest while the mother is sitting a new clutch
  and once again disrupt the sitting regime or may scatter the eggs.
   

• If Eggs are rolled or moved round "violently" or quickly in their early stages of development
  this can damage or kill the embryo.
   

• If the hen is disturbed while she is sitting she may panic and damage the eggs in her haste to exit the Nestbox - Below are some things that may disturb her:
   

  • Night Frights can be responsible.

  • Human interference - always speak before approaching Aviaries to warn your birds u r coming.

  • Cats (esp. on Aviary roof) can frighten the hen out of the nest

  • Sparrow Haws and other "Raptors" around the Aviary can cause the hen to come off the nest in a panic and scatter her eggs.

  • Alarm calls of other birds may panic the hen.

  • Human going into the Nestbox to "check how things are going" may upset the hen and if she comes off the nest she may take some time before she feels secure enough to go back in and in this time the eggs/chicks may chill.

  • Other birds, esp. other Hens looking for a Nestbox for themselves, may chase the hen out.

  • If you breed in cages you shouldn't have as many problems with interference from other birds but a lot of birds are bred en-colony.

There are many reasons babies do not hatch/die in their shell and why eggs are not fertile.

•  I wouldn't always attribute these problems to the hen.  

• For example, eggs can become contaminated and the embryos die

  • egg shells are porous and bacteria/virus, etc., can seep inside...

  • don't handle them with your bare hands, unless you have washed thoroughly

    • or used an "alcohol" Hand Cleaner  similar to those used in Hospitals.
       

• Don't over-calcify the Hen, prior to laying the eggs, with a Calcium supplement (liquid or powder)

  • You can end up with shells that are too thick for the chick to chip its way out of

  • You can also end up with Hens that have a prolapse - trying to lay the egg

  • also Egg-binding can be a problem as the egg is too big/hard-shelled etc.,

    • this is a specific problem with Budgies

    • You should NEVER give Budgies extra Calcium supplements i.e. liquid or powdered calcium.

    • Cuttlefish is ample - they MUST have IODINE blocks tho.

    • A VERY GOOD REASON for following supplementation directions on packaging, meticulously.

    • Over-supplementation of any product can often cause more problems than you are trying to prevent.
       

• Under Calcification can be just as bad:

  • as then the egg can be laid with soft shell which is no good

  • or the egg can be very porous which allows it to lose weight too quickly

  • or allow bacteria in

  • or it can create egg-binding
     

• A very good, high protein diet should be provided prior to laying the eggs to help produce the healthiest eggs/embryos possible.

  • Also, give a good vitamin & mineral supplement.
     

• Don't forget once the eggs have been laid to just provide a basic seed and water diet

  • The Hen goes into a semi-hibernation state (broody) to allow her to incubate her eggs

  • She therefore doesn't need anything more than a maintenance diet.

  • The protein levels are only upped again when the chicks are due to hatch.
     

• Chicks can become exhausted during the 24-48 hour hatching process and die trying to hatch out.

  • this is when the human has, sometimes, to step in and help them out.

  • Chicks sometimes aren't healthy enough and don't develop properly,

  • perhaps the embryos looked fully formed but actually had some type of problem you can't see/identify.

  • If the shell is too hard or covered in hard droppings or hardened dirt off the hens' feet.

  • You may have over-supplemented the hen b4 she laid the eggs esp. over use of Calcium supplements.

    • I usually give a vitamin and mineral supplement with extra protein while the hen is "brewing" her eggs but rarely a calcium supplement.

    • If your hen is fit and healthy then she shouldn't need extra calcium

    • However, AFTER the hen has laid her eggs, I do give calcium supplements (following the directions
      on the tub carefully) to replenish the calcium that creating eggs have taken out of the hen's system.
       

• If you really want to know what is going on, you should take the un-hatched eggs to an Avian vet for evaluation

  • (of course, only after you are absolutely sure the hatch date is passed).  

  • Remember a lot of birds don't start to incubate until their 3rd or 4th egg is laid

  • Sometimes they don't start to incubate until the full clutch is laid

    • So, make sure you take this into account before you presume the worst!!

    • It can be over a week over due - this is where knowing your birds or breed of bird helps.

    • So leave at least 10-14days passed the "due" date you think it should be b4 you break open an egg.

With parrots - not every egg that is laid Hatches?  

• Parrots and birds in general have a high mortality rate...this is why they lay multiple eggs at a time.  

• There's just so many reasons eggs don't hatch and so many variables that play into the equation.

•  I recommend you consult with an avian veterinarian for more specific, expert advice relating to each
  individual situation.  

Soiled Eggs:

• Eggs which show caked droppings of the birds on the shell will usually hatch.

• It is better not to wash them since the shell may break,

• or the washing may remove a natural coating on the shell which prevents germs from entering the egg.

• At times, however, the caked droppings are so thick that the young bird inside cannot break the shell with its egg-tooth.

• When the eggs are so heavily coated with droppings that the pores are sealed and bacteria can enter

• the young bird may die long before hatching.

• Gentle washing in lukewarm water may be tried,

• but it is better to check on care and feeding of the parents to find the cause for the sticky droppings.

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