The generally accepted temperature for incubating almost all birds eggs is between 99.5 and 100.0 degrees F (37.5-37.8 C). Slight variations around this temperature range is alright, but varying more than a degree up or down for extended periods of time can have an impact on your hatch rate, cause birth defects and even cause the eggs not to hatch. A few of the exceptions to this temperature range would be for Emu and Ostrich eggs. Emu eggs require 95.5 to 96.5 degrees F (35.3 - 35.8 C) and Ostrich eggs require 97.0 to 98.0 degrees F (36.1 - 36.6 C)
The amount of time required to incubate an egg can very quite a bit depending on the type of bird. See the chart below. Please note that several factors can change the amount of time listed below. The incubation temperature, humidity level, egg handling, and genetics are some of them.