Swan eggs are incubated at a temperature of about 100 degrees Fahrenheit and a humidity of about 60 percent. The eggs are typically turned slightly every four hours until a few days before the eggs hatch.
Swan eggs must be turned very carefully to prevent the inner membrane from tearing loose from the outer shell of the egg, a problem that often results in the death of the developing swan. Each egg is typically turned about one-quarter turn every 3 to 4 hours in the wild. The eggs should be placed with the narrow end pointed down slightly. Eggs that are incubated may be turned by placing a small board under one edge of the container to lift it slightly and switching the board to lift the opposite side of the container as needed.
The temperature and humidity levels are very important to the process of hatching swan eggs. Even a very small temperature change may prevent the eggs from hatching. To ensure eggs are kept at the proper temperature, eggs need an incubator that uses fans to evenly distribute heat. The incubator should be set to a temperature that ranges from 99.5 to 100 degrees Fahrenheit.
Swan eggs typically hatch after 30 to 37 days, and the eggs should not be turned after day 29 of the hatching process. Swan eggs are typically cared for by the father swan in the wild but may be incubated successfully after seven to 10 days in the nest.