Provine R R
Dev Psychobiol. 1981 May;14(3):279-91. doi: 10.1002/dev.420140317.
Lateral flight evoked by dropping appeared 7-9 days after hatching. Drop-evoked bilaterally symmetrical wing extension and slow, low-amplitude wing-flapping were present by Day 1. Flapping rate measured using strobophotography increased up to approximately 13 days. Normal wing-flapping rates and lateral flight distances were achieved by chicks whose wings were immobilized with elastic bandages from Day 1 until immediately before testing at 13 days, indicating that wing movement is not necessary for the postnatal development of basic wing-flapping and flight. The ratio of wing area to body weight, a morphological index of wing-lift efficiency, rapidly increased up to 13 days and slowly declined through 49 days. The peaking of this ratio at 13 days corresponds to the age at which lateral flight is well established and wing-flapping rate is at its maximum. Thus, the development of wing morphology, wing-flapping rate, and flight are strongly and positively correlated.
孵化后7至9天出现由掉落诱发的侧飞。到第1天时，由掉落诱发的双侧对称翅膀伸展以及缓慢、低幅度的翅膀扇动就已出现。使用频闪摄影测量的扇动速率在大约13天前不断增加。从第1天起直到13天测试前一直用弹性绷带固定翅膀的雏鸡，其翅膀扇动速率和侧飞距离正常，这表明翅膀运动对于出生后基本翅膀扇动和飞行的发育并非必要。翅膀面积与体重之比是翅膀升力效率的形态学指标，在13天前迅速增加，到49天缓慢下降。该比例在13天达到峰值，这与侧飞良好确立且翅膀扇动速率达到最大值的年龄相对应。因此，翅膀形态、翅膀扇动速率和飞行的发育呈强烈正相关。
