Page 149 - Design in Nature

Spongy tissue
(shock absorber)
Upper beak
support point

Upper beak
The tip of beak is
pushed backward
and downward.

The muscle pushes the back of the jaw
forward. The upper beak shifts upward,
absorbing the impact of the hit.

In the upper beak movement of a woodpecker, when the beak hits the tree, the bird
experiences a tremendous impact. However, there are two mechanisms created to absorb
this impact. The first is the spongy connective tissue between the skull and the beak, which
softens the impact greatly. The second mechanism is the tongue of the woodpecker. The
tongue circles around inside the skull to attach to the top of the woodpecker's head. This
arrangement of the tongue muscle is a bit like a sling and may reduce the shock of each
beak-to-tree impact. Therefore, the impact (softened by the spongy tissue) is almost
reduced to nothing.

and beak line up perfectly on a straight line, but the smallest deviation could
cause severe ruptures in the brain.
The impact of this kind of hitting is in effect no different from banging
the head against a concrete wall. It takes extraordinary design for the bird’s
brain not to be injured. The skull bones of the majority of birds are joined
together, and the beak functions with the motion of the lower jaw. However,
the beaks and skulls of woodpeckers have been separated by a spongy tissue
that absorbs the shocks of impact. This flexible substance works better than
shock-absorbers in automobiles. The excellence of this material derives from
its capability of absorbing impacts of very short duration and then restoring
itself its to original condition immediately. This performance is maintained
even where nearly nine to ten hits are made per second. This material is far
superior to materials developed by modern technology. The isolation of the
beak from the skull by this extraordinary method enables the compartment
holding the woodpecker’s brain to move away from the upper beak during
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hits, and this works as a secondary mechanism for absorbing shocks.