How do Birds Plundge into Water at High Speeds

Some birds,to surprise their prey, have to travel into the water at speeds up to 50mph.  Virginia Tech helps explain how the birds manage these high speed dives. "We were interested in what happens when objects plunge into water, so we looked for examples in nature; the gannets are incredible," said Sunny Jung, an associate professor of biomedical engineering and mechanics in the College of Engineering and an expert in fluid biomechanics.

 Their analysis revealed that the transition from stability to buckling depends on the geometry of the head, the material properties of the neck, and the impact speed; at typical gannet diving speeds, the birds' narrow, pointed beak and neck length kept the drag force in a safe range. "What we found is that the gannet has a certain head shape, which reduces the drag compared to other birds in the same family," Jung said.  They also discovered that right before the birds enter the water, the bird will contact its neck, and as it hits the water, straighten it out with all of its force.This assist in a straight entry and protects the neck.

They then relate this to humans. Humans cannot survive an impact like this because we were not built for it. Our bodies do not contact and we do not have the arrow dynamics like the bids do.