Diving bird
Diving birds are birds which plunge into water to catch fish or other food. They may enter the water from flight, as does the brown pelican (Pelecanus occidentalis), or they may dive from the surface of the water. More than likely they evolved from birds already adapted for swimming that were equipped with such adaptations as lobed or webbed feet for propulsion.[1]
Foot-propelled diving birds
Some diving birds - for example, the extinct Hesperornithes of the Cretaceous Period - propelled themselves with their feet. They were large, streamlined, flightless birds with teeth for grasping slippery prey. Today, cormorants (family Phalacrocoracidae), loons (Gaviidae), and grebes (Podicipedidae) are the major groups of foot propelled diving birds.[2]
Wing-propelled diving birds
Other diving birds are wing-propelled, most notably the penguins (Sphenisciformes), dippers (Cinclus) and auks (Alcidae).[3]
Feature
Plunge-diving is a special form of foraging that involves a transition from air to water.[citation needed] But, what makes a plunge-diving bird a plunge-diving bird? Plunge-diving birds have a couple of unique features to make them special and allow them capable of doing diving. The first special thing is the beak of plunge-diving birds. Beak angle ratio is a ratio of the smaller-to-larger beak angles. When the top and side angles are similar together, high beak angle ratios result, while when the difference is greater, low beak angle ratios result. Plunge-diving birds generally have a higher beak angle ratio than any others.[4] Plunge-diving birds' foraging behavior also affects the evolution of rhamphotheca and skeletal beak shape. Plunge-diving birds have narrower and thinner rhamphotheca cause them to have different beak shapes.[5]
The other special feature is the neck of plunge-diving birds. Plunge-diving birds can dive from heights up to 45 m and reaching speed up to 24 m/s without causing any injuries. Their neck plays a big role when plunge-diving. Their neck muscle will contract during the impact process, and the tendons will apply tension to the bones to keep the neck being straighten serve as a stabilizing force during plunge-diving.[6] This allows them to be able to plunge-dive safely, having deeper dives and thereby increasing the volume of water accessible to the birds while surprising the prey.[7] However, it also brings up a negative that plunge-diving birds dive less often than those who dive from the water's surface due to this unique forage method.[8]
Another special feature would be the morphing wings. The morphing wing is the ability to change the wingspan in the process of flying and adapt to various aerodynamic requirements or flight conditions. Different shapes of a bird's wing are important in determining the flight capabilities, they can affect aerodynamic performance and maneuverability.[9][circular reference] In the fully open condition, the morphing wing reaches the maximum surface area and has a 32% higher lift coefficient which to achieve high maneuverability at low speed. In the fully closed condition, the morphing wing would minimize the surface area and reduce the drag coefficient by 29.3%, from 0.027 to 0.021, to achieve high-speed flight.[10]
See also
- Flying submarine – Seaplane that can dive underwater
- Physiology of underwater diving – Adaptations of marine vertebrates to diving
References
- ^ Jung, Sunghwan; Gerwin, John; Dove, Carla; Gart, Sean; Straker, Lorian; Croson, Matthew; Chang, Brian (2016-10-25). "How seabirds plunge-dive without injuries". Proceedings of the National Academy of Sciences. 113 (43): 12006–12011. Bibcode:2016PNAS..11312006C. doi:10.1073/pnas.1608628113. ISSN 0027-8424. PMC 5087068. PMID 27702905.
- ^ National Geographic (2007-08-31), Underwater Diving Bird | National Geographic, retrieved 2019-06-25
- ^ "Alcidae". Alcidae Inc. Retrieved 2019-06-25.
- ^ Sharker, Saberul; Holekamp, Sean; Mansoor, Mohammad; Fish, Frank; Truscott, Tadd (2019-08-29). "Water entry impact dynamics of diving birds". Bioinspiration & Biomimetics. 14 (5): 056013. Bibcode:2019BiBi...14e6013S. doi:10.1088/1748-3190/ab38cc. PMID 31387087.
- ^ Eliason, Chad; Straker, Lorian; Jung, Sunghwan; Hackett, Shannon (2020-05-26). "Morphological innovation and biomechanical diversity in plunge‐diving birds". Evolution. 74 (7): 1514–1524. doi:10.1111/evo.14024. PMID 32452015. S2CID 218895071.
- ^ Jung, Sunghwan; Gerwin, John; Dove, Carla; Gart, Sean; Straker, Lorian; Croson, Matthew; Chang, Brian (2016-10-25). "How seabirds plunge-dive without injuries". Proceedings of the National Academy of Sciences. 113 (43): 12006–12011. Bibcode:2016PNAS..11312006C. doi:10.1073/pnas.1608628113. ISSN 0027-8424. PMC 5087068. PMID 27702905.
- ^ Coudert, Yan; Grémillet, David; Ryan, Peter; Kato, Akiko; Naito, Yasuhiko; Maho, Yvon (2003-12-22). "Between air and water: the plunge dive of the Cape Gannet Morus capensis". Ibis. 146 (2): 281–290. doi:10.1111/j.1474-919x.2003.00250.x.
- ^ Green, Jonathan; White, Craig; Bunce, Ashley; Frappell, Peter; Butler, Patrick (2009-11-04). "Energetic consequences of plunge diving in gannets". Endangered Species Research. 10: 269–279. doi:10.3354/esr00223.
- ^ Bird's wing
- ^ Luca, Matteo; Mintchev, Stefano; Heitz, Geremy; Noca, Flavio; Floreano, Dario (2017-02-06). "Bioinspired morphing wings for extended flight envelope and roll control of small drones". Interface Focus. 7. doi:10.1098/rsfs.2016.0092. PMID 28163882.