Abstract
During my October, 1980 visit to England it was my very good pleasure to be introduced to two of the foremost aviculturists in England and no doubt in the world. Such dedication needs to be shared with Amencan av1cultunsts. The sight of seeing so many difficult to breed psittacmes being bred successfully in such dismal weather and a collection of birds in such excellent condition was the highlight of my visit to the U.K. and Europe. There were fourteen juvenile Plum-crowned pionus (P. tumuktuosus tumultuosus). By the way, these were first bred by Pat and john Stoodley in 1977 making it a first world captive breeding no doubt. The eggs were all incubated and chicks hand raised from day one. In all, about fifty large type psittacines eggs were incubator hatched and hand reared in 1980.
Such success has, needless to say, been highly criticized by older aviculturists of the traditional English school. But I observed many of these critics allowed eggs and chicks to remain in the nests during inclement weather thus allowing them to be destroyed by the cold temperatures. The opinion of the owners was if the chicks aren't parent raised it isn't natural and therefore the young should not be removed from the nests. One would think in a country so advanced in civilization the average av1culturis: would be equally sympathetic to his birds.
Pat and john are far ahead of their time and this ts the kind of thinking aviculture needs today if we are to justify the taking of birds from the wild. WE MUST BE ABLE TO SHOW WE CAN SUCCESSFUUY CAPTIVE BREED, and thereby silence the voices of our conservationist critics. The Stoodleys have
proved this point in a remarkable way. I sincerely trust American readers will appreciate the practical data their article contains.
Like most people keeping the larger parrots, my wife and I have been concerned over the number of dead in shell we have experienced in our collection. This problem we felt was because we were unable to provide the correct humidity in the aviaries for parrots of the New World. We did have a little success in hatching a few eggs in a small incubator, but considered the overall experiment far from satisfactory.
We were unable to obtain much useful or helpful information on incubators until we met Mr. Philip Glasier of the Newent Falconry Centre. It was pleasing to meet a man of such outstanding achievement who was so generous with his knowledge. My wife and I were invited to spend the day at the centre. We were soon in a room with his students discussing the merits of the unit that Mr. Glasier had built. I sketched the unit and took notes of this successful incubator. Before leaving the centre we walked through the grounds with Mr. Glasier, his birds were delighted to see him. On the day we visited the centre, there was a heavy fall of snow, therefore few visitors were to be seen but for us. It was the perfect day to observe this vast collection of birds of prey.
Having obtained the components required, the incubator was assembled. The unit takes the form of a simple cube, each side being approximately 29. 5 ins. (75 cm.) in length. However, two thirds of one side forms a door which opens to the full width of the cube. A large opening is essential to provide easy manipulation of the eggs within and the removal of the egg tray. Above the door is a small glass panel, this allows observation of the thermometer without the incubator door being opened. On one side at about 4 ins. (10 cm.) above the base are three holes, on the opposite side three similar holes exist, but are twice the distance above the base. Each hole is approximately 3/4 ins. (2 cm.) in diameter. Their presence is to ensure a constant change of air within the incubator.
The sides of the cube are double skinned to restrict heat loss, simple household insulation is placed between the walls which are about 3/4 ins. (2 cm.) apart, even the door is insulated in such a way. The inside surface is Formica and the exterior plywood. Placed centrally within the incubator is the egg tray, it consists of many wooden dowels about 1/2 ins, (I 1/2 cm.) in diameter, the dowels are covered in plastic tu be to aid cleaning and more importantly the turning of the eggs. The tray is supported on slides so it may be removed as mentioned before. Positioned on the top and bottom of the incubator are two fans, these fans are essential to assist the circulation of heat and air. Surrounding the fans are two heating elements each of 120 watts, however, the heating elements are never used at their maximum output due to the use of a heavy duty lighting dimmer. The temperature within the incubator is controlled by aJumo Adjustable Contact Thermometer type MSlZZ coupled to ]umo Relay GKT 15-0, also aJumo Thermometer 1411 at egg level. A small light bulb illuminates the inside of the incubator, this enables observation of the eggs and thermometer.
The completed unit is most accurate, capable of maintaining temperature to within 0.2 of a degree. I select a temperature of 98. 5 degrees F. 3 7C with confidence that it will be maintained. To obtain humidity within the unit I use one or two flat dishes about 7 ins. (17 .8 cm.) in diameter. These contain water. To increase humidity I place the dishes closer to the fan and to reduce humidity they are moved away from it. If some adjustment in surface area of water is necessary a smaller water container sometimes is useful.
Next came the problem of what eggs to select for the experiment. Although Mr. Glasier obtains almost one hundred percent success rate, we were not so optimistic, however a number of Pionus eggs were put up. They were marked with an arrow on each side of the egg. These arrows are in opposition to each other which enables me to rotate the egg 180 degrees, then counter rotate so the turning is accomplished without the egg rolling continually in the same direction, which would be most harmful. If the egg is continually turned in the same direction, there is a likelihood the embryo would be strangled. I turn the eggs as near as possible every two hours ideally seven times a day. I suggest a minimum of five times...