Diving is a lot of pressure for a bird. Take the Northern Gannet, which is often likened to a torpedo, as it plunges of feet to spear fish from the ocean, sometimes reaching 60 miles an hour.
Plummeting from sky into water is a huge force, 鈥渆specially when you鈥檙e moving so fast,鈥 says Sunghwan Jung, an assistant professor at Virginia Tech. He and a team of Virginia Tech engineers and staff from the Smithsonian Museum of Natural History including of the Division of Birds, were curious why humans get injured by high impact dives, but seabirds do not.
Since the scientists couldn鈥檛 catapult live birds into the ocean, they dropped dead and mock seabirds into a four-foot tank of water. Their study subjects included a dead gannet (a frozen specimen donated by the North Carolina Museum of Natural History) and 3D-printed seabird replicas.
After testing out the dead specimen, the team discovered that the highest probability of the gannet鈥檚 neck snapping came mid-dive鈥攚ith the head fully submerged and the body still above water. 鈥淭here is was a very strong compressive force on the bird鈥檚 neck at this point,鈥 says Jung, who recently presented this research at the .
When the team tried out their next subject, a 3D bird model, they saw that the longer the 鈥渘eck鈥 was, and the faster the 鈥渂ird鈥 fell, the more likely the neck was to buckle and break.
Jung thinks this could mean that birds have an ideal ratio between neck length, diving speed, and other factors that ensure survival during dives: 鈥淓volution helps to choose the right speed,鈥 he says.
The one element that Jung鈥檚 team could not account for is the form a live bird takes upon diving. 鈥淎 gannet folds itself up into an arrow,鈥 says , the Marine Bird Program Director at the Biodiversity Research Institute. This streamlined shape allows the bird鈥檚 body to absorb some of the impact, taking a little pressure off the neck.
Jung鈥檚 team鈥檚 research is still preliminary, and they鈥檙e devising a final paper that Jung hopes to publish this summer.
Stenhouse says that gannets compensate for their long necks in many ways, including internal and . There must be a maximum force that these birds can bear, he says, but they can dive from almost any height (very low to over 200 feet high)鈥攚e just can鈥檛 seem to find their limit.
See award-winning photographer Matt Doggett's , or about this bird's diving prowess from 爆料公社 magazine.