How woodpecker protects its brain from concussion during pecking compared with chicken and pigeon

Yang Li,Qing Ling Meng,Cheng Wei Wu,Wei Zhang,Gang Jiang

doi:10.1063/5.0004546

Yang Li, Qing Ling Meng + Show 3 more

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https://doi.org/10.1063/5.0004546

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Abstract

Head injury has become a threat to human life in transportation accidents, construction. and sports. However, woodpeckers can avoid injuring their brain during high velocity and frequency pecking. To reveal the underlying secret, the pecking process of woodpeckers is simulated and compared with that of chickens and pigeons to study the stress wave propagation in their head. The pecking data of live chickens and pigeons are simultaneously obtained from the force sensor and the high-speed video system. The morphological information of the three birds’ heads is also investigated using Micro Computed Tomography (Micro-CT) scanning. The results show that the woodpecker has the highest skull volume fraction and beak length fraction, which could potentially increase its head structural strength and provide more space to dissipate impact stress. The finite element head models of the woodpecker, chicken, and pigeon are established based on the micro-CT images and performed pecking process simulations. The simulated results suggest that the stress wave propagates through both the upper-beak and lower-beak of the woodpecker to ensure the enough structural strength in order to overcome the fierce impact. On the other hand, the structural strength requirement of the chicken and pigeon is not as high as the woodpecker due to their lower pecking intensity. Setting the stouter lower-beak of the chicken and the pigeon as the primary wave propagation path not only ensures their head safety but also avoids direct impact to their brain. The biomechanical design of the bird’s heads, setting a special propagation path for the stress wave, may inspire new approaches to improve and design impact resistance equipment.

Highlights

A human head often suffers various injuries when it is subjected to an external force
We conducted the pecking experiments of the chicken and the pigeon to observe their pecking motion and test their pecking force, velocity, and frequency and compared the results with the pecking data of the woodpecker based on previous studies
Tracing this phenomenon for its source, finite element (FE) models of the three birds were built based on micro-computed tomography (CT) images, material properties, and impact analysis

Summary

Introduction

A human head often suffers various injuries when it is subjected to an external force. Head injury involves damage to the skull and scalp and often results in traumatic brain injury (TBI).. Head injury is a major cause of death and disability worldwide, especially in children and young adults. During 2002–2006, the incidence of head injury is about 1.7 × 106 people in the United States each year. About 3% of these incidents leads to death.. Many birds drum with their beak on hard and solid objects to feed themselves without head injury. The woodpecker is a typical and remarkable bird to have a wonderful protecting ability from TBI during its high-speed pecking. Other birds evolve their own protective strategy to avoid TBI during feed related pecking

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