Function
In most situations, the alula is held flush against the wing; however, it can be manipulated. When flying at slow speeds or landing, the bird moves its alula slightly upwards and forward, which creates a small slot on the wing's leading edge. This functions in the same way as the slats on the wing of an aircraft, allowing the wing to achieve a higher than normal angle of attack – and thus lift – without resulting in a stall. During stretching of the wing down toward the ground, the alula is abducted from the wing and can be clearly viewed.
Read more about this topic: Alula
Famous quotes containing the word function:
“As a medium of exchange,... worrying regulates intimacy, and it is often an appropriate response to ordinary demands that begin to feel excessive. But from a modernized Freudian view, worrying—as a reflex response to demand—never puts the self or the objects of its interest into question, and that is precisely its function in psychic life. It domesticates self-doubt.”
—Adam Phillips, British child psychoanalyst. “Worrying and Its Discontents,” in On Kissing, Tickling, and Being Bored, p. 58, Harvard University Press (1993)
“... the function of art is to do more than tell it like it is—it’s to imagine what is possible.”
—bell hooks (b. c. 1955)
“If the children and youth of a nation are afforded opportunity to develop their capacities to the fullest, if they are given the knowledge to understand the world and the wisdom to change it, then the prospects for the future are bright. In contrast, a society which neglects its children, however well it may function in other respects, risks eventual disorganization and demise.”
—Urie Bronfenbrenner (b. 1917)