Alula

As Alula ( Daumenfittich, Eckfittich, even after rocker ) refers to the feathers on the thumb of the bird's wing. In general, there are three or four wide, solid and pointed feathers with short powerful coils. The Alula is made ​​large in those species of birds that fly frequently braking, eg forest dwellers.

The Daumenfittich has the task not to let the air flow over the wing even at a steep angle of attack tear, so that the dynamic lift of the wing is maintained. The Aulula thus fulfills the same function as the slats on aircraft.