Q: I have a cockatiel breeding pair that was doing well with the eggs until the male got out the window when someone opened the screen. The mother has now rejected the eggs. I have put the eggs in an aquarium with a bowl of water in a clean nest box covered with a damp, clean rag and a lamp for warmth. I check on the eggs to make sure they are not too hot but warm and comfy. Should I leave the heat lamp on all night or shut it off and cover the whole incubator? If the eggs have gotten cold, does that mean they will be no good?
Linda S. Rubin explains:
Unfortunately, you must have discovered by now that the eggs, if fertile, have addled or are not viable. All fertile eggs require a consistent and very precise temperature at all times and are brooded full-time by both parents. The parent birds take turns to be certain the eggs are correctly incubated so the developing embryo does not become chilled and die.
Although keeping a heat lamp on full time can appear to be the answer, it does not deliver the precise temperatures that brooding birds provide. Parent birds have an area on the lower breast beneath the feathers called the “incubation patch,” which is exposed during nesting. The incubation patch functions to deliver heat more accurately and directly to the eggs without the feathers acting as a barrier. The incubating bird can, in fact, control the temperature and amount of heat provided through the incubation patch as needed.
In order for eggs to mature into viable young, in addition to heat, the eggs must be turned at least once per day. Turning the eggs allows the growing embryo to turn inside the egg and prevents the embryo from sticking to the cell membrane so that it can continue to grow. Parent birds know instinctively when to carefully turn their eggs within a 24-hour period, and are much more adept to this task than humans.
Barring the presence of parent birds to incubate the young, eggs can be placed in a commercial, or adapted incubator, and regulated for temperature, humidity and rotation so that embryos mature and hatch out healthy. Although humidity can be provided through additional sources, such as a small cup of water, damp cloths or wet sponges, incubators can be set for more precise readings. However, once hatched, the task of hand-feeding the newborns now becomes necessary and is not recommended for the novice or inexperienced.