late air, as opposed to a still air machine, which relies on convection) are far more accurate when it comes to maintaining a constant temperature.

The five key elements of successful incubation are as follows:

1. Quality fertile egg.

2. Hygiene.

3. Temperature control.

4. Correct amount of turning.

5. Humidity control.

Quality Fertile Egg

For an egg to stand any chance of hatching, it has to be of the highest quality. Diet is the main contributing factor, and small

inadequacies in the female's diet will show up as poor hatchabilitv. Unfortunately, unless the egg has a poor shell qual

tors and there is a high skill factor to be learned as to their husbandry. Most larger breeders tend to shy away from this method as it is another job in itself. An incubator is required to complete the hatching when using nonraptor surrogates.

 

INCUBATORS

Over the last twenty years the use of electromechanical incubators has grown in popularity not only with raptor breeding but also in many other branches of aviculture.

Major steps forward have occurred in this field not only with the advancement of the machines themselves but also in our understanding and knowledge of the parameters needed to successfully hatch a high percentage of eggs.

It is essential that a deep understanding of the egg's needs during incubation be acquired prior to trying to incubate valuable eggs. Once a good grounding has been acquired then you need to gain experience, which can only be obtained by trying out your techniques. In most cases you are chasing your own tail, as with generally only a small number of eggs being produced and incubated annually, it is hard to gain experience. I have been fortunate in this respect; as well as incubating several hundred raptor eggs annually we also house a large parrot collection and it is rare for us not to have at least a few eggs in the incubators all year round.

As to the question of which is the best type and make of incubator, again experienced breeders hotly debate this. We use the RollX and TurnX incubators produced by Lyon's Electrical Company and during the last season we have added a number of Grumbach S84 incubators which we are extremely impressed with. There are a number of other makes of incubators which

some breeders have expressed their confidence in. It is now the accepted view that forced air incubators (ones with a fan to circu

All incubators must be cleaned thoroughly and fumigated prior to use, and frequently throughout the incubation season. This is also the case for egg transport boxes, scales and any other areas the eggs may come in contact with and particularly the human hands.

Eggs that we find to be dirty or soiled when removed from the nest, are cleaned with warm water before being placed in the incubator. There are a number of commercial egg sanitant solutions available, and if used, it is imperative that the instructions are followed exactly as they have the potential to harm eggs if not.

Types of bacteria found on a tree nesting accipiter egg against a cliff nesting falcon egg will vary, and although it usually doesn't affect its natural host it may well be lethal to another species eggs. With this in mind we try not to have too dissimilar eggs within the same incubators. We have found merlin eggs in particular, to be very prone to cross infection from other eggs.

Eggs that are found to be infertile or which have ceased developing (died) when candled are removed from the incubator

immediately.

Hygiene levels cannot be over stated in incubation, and it is a constant battle. In the ideal world each egg would have its own

ity, which is obviously seen, the egg gives little away optically as to its internal qualities. Eggs which fail to hatch, can he sent for laboratory evaluation of their nutritional makeup, with a view to finding any shortfall. However the results are usually compared with those obtained from poultry and any comparisons should he viewed sceptically.

Fertility can usually he determined by clay 5 or 6 of incubation via candling. Candling, is the term used to describe placing the egg over a cool strong contained light source to view the contents of the egg through the shell. At this period of incubation, if fertile, the yolk will become mare defined in shape and begin to expand in size. Accipiter, buteo and eagle eggs are more difficult to candle than falcons due to their more dense and thicker shells.

Although eggs have a mild resistance to bacteria found in the wild nest, the bacteria found in captivity is generally of a different type and can be lethal. As an egg is laid it cools and contracts rapidly, any bacteria in contact with the egg may be drawn through the shell. For this reason nest ledges and platforms

should be kept as clean as practically possible and yet again clue to easy access this is more easily achieved with imprinted birds.

Modern Captive Breeding – Part III  ...continued

 

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