![]() "For the wing to fly better, the air has to move closer to the wing. Here they observed that a tiny vortex from the alula tip presses the air flow over the wing and makes the air flow better attached to the wing surface. Then the researchers moved on to the wind tunnel experiments where they visualized the movement of tiny particles around magpie wings. "But with the alula they seem to turn more easily". ![]() Sang-im Lee, the first author of the paper. "It's not that they cannot fly without the alula." says Dr. They started with observing magpies in the aviary when the birds moulted the alula feathers. The researchers were interested in the flight of magpies. This study was conducted by a research team of biologists and mechanical engineers at the Seoul National University. Why do they use it? How the tiny feathers can help them land softly?Ī recent article published in Scientific Reports says that the secret is a small vortex of air that is formed at the tip of the alula feathers. From countless observations, it has been known that the birds use a small group of feathers, called "the alula", a thumb-like structure that is present at the bend of the wing, in slow and steep flight such as landing. One mystery of birds' flight is solved! The elegance of birds' flight, their seemingly effortless aerial turns and the softness of their landing, have been envied by many people. All the best :)Ĭanon 7D Mk ll & Canon EF 100-400mm f/4.5-5.6L IS II USM + Canon 1.4x lll teleconverter – 1/2500, f8, ISO 640, 0 exposure compensation.Image: The alula feathers, the thumb-like structure, on both wings are well visible. For those that already knew about this function, I still hope you enjoyed the images. I hope you enjoy this series of images showing the use of the 'alula' and learning about it for those that didn't know. He only leveled it off again once he was flying away as you can see in the following photos :) This Bald Eagle (I believe a 4 year old) was coming in for a fish at the Strait of Canso, Nova Scotia, Canada and had the alula up when swooping in, even though he didn't actually get the fish. Fascinating, isn't it? Call me crazy, but I find behavioral actions and functions very interesting. So that is what the alula is and what it does. The tip of the alula forms a tiny vortex that forces the airflow over the wing to better bind to it. During stretching of the wing down toward the ground, the alula is abducted from the wing and can be clearly viewed." 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. 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. Function:In most situations, the alula is held flush against the wing however, it can be manipulated. Like the larger flight feathers found on the wing's trailing edge, these alula feathers are asymmetrical, with the shaft running closer to anterior edge. There also are minor covert feathers overlying the flight feathers. The alula is the freely moving first digit, a bird's "thumb", and typically bears three to five small flight feathers, with the exact number depending on the species. The word is Latin and means "winglet" it is the diminutive of ala, meaning "wing". "The alula, or bastard wing, (plural alulae) is a small projection on the anterior edge of the wing of modern birds and a few non-avian dinosaurs. First, for those of you that are asking the question, "What is the Alula?", here is an explanation from Wikipedia:
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |