After that comes a year or more of extreme physical stress and pain, during which the subject must be kept quiet, warm, and well fed. The bones lighten and become porous, the whole upper body musculature changes, and bony protuberances, developing rapidly from the shoulder blades, grow out into immense alar processes. The final stage is the growth of the wingfeathers, which is not painful. The primaries are, as feathers go, massive, and may be a meter long. The wingspread of an adult male Gyr is about four meters, that of a woman usually about a half meter less.
Stiff feathers sprout from the calves and ankles, to be spread wide in flight.
Any attempt to interfere, to prevent or halt the growth of wings, is useless and harmful or fatal. If the wings are not allowed to develop, the bones and muscles begin to twist and shrivel, causing unendurable, unceasing pain. Amputation of the wings or the flightfeathers, at any stage, results in a slow, agonizing death. Among some of the most conservative, archaic peoples of the Gyr, the tribal societies living along the icy coasts of the north polar regions and the herdsfolk of the cold, barren steppes of the far south, this vulnerability of the winged people is incorporated into religion and ritual. In the north, as soon as a youth shows the fatal signs, he or she is captured and handed over to the tribal elders.