Also found in: Dictionary, Thesaurus, Medical, Wikipedia.


Digit of a bird wing homologous to the thumb.



(also known as bastard wing or spurious wing), a group of feathers attached to the first digit of bird wings. The alula usually consists of four feathers, but sometimes there are three (certain passerines and Picidae) or six (the touraco). It can move forward and upward, preventing disruption of the airstream from the wing at large angles of incidence. The alula is most developed in forest birds that have rounded wings and are capable of maneuverable flight.

Mentioned in ?
References in periodicals archive ?
With integrated products and services, Alula allows independent security companies to bank on a single platform for hundreds of security configurations -- the two-room townhouse, the suburban spread, the small shopkeeper and the growing business.
This allowed Ras Alula and Ras Mengesha's Tigrayan fighters to finish crushing the remainder of Albertone's brigade by swift movements associated with a deluge of rifles firing, spears hurling, swords swirling, and hand-to-hand combat.
Alula village head Hareed Issa Omar says the Norwegian team fired first, killing a Somali and a Yemeni man.
Surely the most amazing star of the Three Leaps is Alula Australis, better known as Xi Ursae Majoris.
25a Margen posterior de la alula convexo; ala no particularmente alarga ni delgada .
Through the scope, the distinctive black alula feather in the wing was clearly visible.
Joining him on the vocals for the pulsating Middle Eastern rap-reggae-inspired tune are Justin and Jared Stein singing in English and Alula Tzadik singing in Arabic.
Mechanisms of competition between Onychocella alula (Hastings) and Antropora tincta (Hastings) on an Eastern Pacific rocky shoreline.
This cluster, called the alula, slots open (projects upward) to create a small airfoil just above and in front of the wing.
The grant will also fund an endowment for studying the Brighamia rockii, also called the alula, in the National Collection of Endangered Plants.
By moving that digit, a bird can separate the feathers of the alula from the rest of the wing, creating a slot that helps channel air over the flight feathers.
Alula Abate, finally, examines demography, migration and urbanisation.