@article{ref1,
title="How seabirds plunge-dive without injuries",
journal="Proceedings of the National Academy of Sciences of the United States of America",
year="2016",
author="Chang, Brian and Croson, Matthew and Straker, Lorian and Gart, Sean and Dove, Carla and Gerwin, John and Jung, Sunghwan",
volume="113",
number="43",
pages="12006-12011",
abstract="In nature, several seabirds (e.g., gannets and boobies) dive into water at up to 24 m/s as a hunting mechanism; furthermore, gannets and boobies have a slender neck, which is potentially the weakest part of the body under compression during high-speed impact. In this work, we investigate the stability of the bird's neck during plunge-diving by understanding the interaction between the fluid forces acting on the head and the flexibility of the neck. First, we use a salvaged bird to identify plunge-diving phases. Anatomical features of the skull and neck were acquired to quantify the effect of beak geometry and neck musculature on the stability during a plunge-dive. Second, physical experiments using an elastic beam as a model for the neck attached to a skull-like cone revealed the limits for the stability of the neck during the bird's dive as a function of impact velocity and geometric factors. We find that the neck length, neck muscles, and diving speed of the bird predominantly reduce the likelihood of injury during the plunge-dive. Finally, we use our results to discuss maximum diving speeds for humans to avoid injury.<p /> <p>Language: en</p>",
language="en",
issn="0027-8424",
doi="10.1073/pnas.1608628113",
url="http://dx.doi.org/10.1073/pnas.1608628113"
}