Why do woodpeckers resist head impact injury: a biomechanical investigation

PLoS One. 2011;6(10):e26490. doi: 10.1371/journal.pone.0026490. Epub 2011 Oct 26.


Head injury is a leading cause of morbidity and death in both industrialized and developing countries. It is estimated that brain injuries account for 15% of the burden of fatalities and disabilities, and represent the leading cause of death in young adults. Brain injury may be caused by an impact or a sudden change in the linear and/or angular velocity of the head. However, the woodpecker does not experience any head injury at the high speed of 6-7 m/s with a deceleration of 1000 g when it drums a tree trunk. It is still not known how woodpeckers protect their brain from impact injury. In order to investigate this, two synchronous high-speed video systems were used to observe the pecking process, and the force sensor was used to measure the peck force. The mechanical properties and macro/micro morphological structure in woodpecker's head were investigated using a mechanical testing system and micro-CT scanning. Finite element (FE) models of the woodpecker's head were established to study the dynamic intracranial responses. The result showed that macro/micro morphology of cranial bone and beak can be recognized as a major contributor to non-impact-injuries. This biomechanical analysis makes it possible to visualize events during woodpecker pecking and may inspire new approaches to prevention and treatment of human head injury.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Beak / physiology
  • Biomechanical Phenomena*
  • Birds / injuries
  • Birds / physiology*
  • Brain Injuries / prevention & control*
  • Craniocerebral Trauma / prevention & control*
  • Finite Element Analysis
  • Skull / physiology
  • Tomography, X-Ray Computed
  • Video Recording