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Eggs and what develops

Cockatiel hens usually lay between 3-7 eggs with 5 being normal however some eager hens can lay continually until chicks have been born, these hens need to watched closely for egg binding or lack of fitness due to the strain of calcium absorption required to produce the eggs! A good breeding age is at least 12mths with 18-24 being ideal with fewer complications to deal with; also mature birds seem to do everything right with brooding. Hens will incubate from late afternoons till early mornings when the cock will take over and relieve the hen. Some devoted pairs especially those housed on their own will share incubation duties during the day. 

The first eggs usually appear 10-14 days after pairing and are laid every other day. Brooding doesn’t commence until the 3rd egg is laid giving parents the opportunity to have at least the first 3 chicks hatch together. After approximately 5-7 days of incubation a cockatiel egg can be checked for fertility using an egg candler or a strong flash light. As “Foreshaw says” a fertile egg is Broad-Elliptical with a slight gloss or opaque look quite distinguishable against an infertile egg which is clear and dull! Once candled a fertile egg will show red blood veins thru the entire egg similar to a spider web leading to embryo viewed as a little blood dot which will increase in size as it develops. 

By the 8-10th day of fertility a candled egg will show signs of heartbeat coming from the embryo which can be very thrilling and rewarding for 1st timers. Also appearing will be an Air-Sac at the large end of the egg, the size of the sac is determined by relative humidity. Too much humidity will create a smaller air sac which will cause the chick too swell in the egg resulting in the chick being smothered and usually fatal if not assisted at hatch! Too little humidity creates a larger air sac will little moisture for the chick to move and revolve whilst hatching also causing the chick to adhere to the membrane which is identified by a large hole whilst trying to hatch, this also can be fatal if not assisted in hatching! 

After approximately 17days incubation candling the egg will reveal the air-sac has tilted by 45 degrees, this period of brooding is called the “Internal Pip” which also can be detected without candling by a dent which will appear at the large or air sac end of the egg. This process of hatching with the chick now breaking through the membrane into the air cell where it will begin to take its first breath with a supply of fresh air created by the pip and if you listen closely you will hear their first chirps whilst chipping away in a circular motion around the shell. Usually without complications a chick will appear within 24-48 hrs of the pip any longer than this is a general warning for signs of difficulty and an assisted hatch might be required!

So as you can see a cockatiel has its work cut out making sure all conditions are met and do rely greatly on breeders to accommodate their requirements. A shallow water dish is appreciated greatly by brooding hens who love nothing more than to take a dip in the water to help maintain humidity levels in the nest box especially in warmer climates! Also a good supply of calcium and sunlight are the main ingredients for healthy eggs and chicks. 

If at any stage of incubation a criteria is not met by one or both parents for one reason or another cockatiel eggs can be fostered to another pair usually without fuss but make sure the fostering pairs biological clock is in time with those being fostered although I personally feel it’s better to try and educate birds to become good breeders rather than egg producing machines!

Bent Tails

Frank De Luca of Hillcrest Cockatiels

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