For the Birds – Ig Nobel Awards and Woodpeckers
You can’t say scientists don’t have senses of humor. On October 5, the 16th Annual Ig Nobel prizes were awarded at Harvard. The Ig Nobel awards are given out around the time that the Nobel prizes are awarded.
The Ig Noble Prizes are awarded to scientists whose work first makes you laugh and then makes you think. Scientific work that is awarded an Ig Nobel Prize is usually serious, carefully done research, published in reputable scientific journals, but may cause you to ask “Huh?” when you first hear about it.
Here are some of the projects that have received Ig Nobel Prizes. Antonio Mulet from the University of Valencia received an Ig Nobel Chemistry Prize for their work on ultrasonic velocity of cheddar cheese as affected by temperature. Basile Audoly and Sebastien Neukirch of the Université Pierre et Marie Curie in France received an Ig Nobel Physics Prize for their insights into why, when you bend dry spaghetti, it often breaks into more than two pieces. How about the Ig Nobel Biology Prize won by Bart Nols of the University of Wageningen in the Netherlands for demonstrating that female malaria mosquitos are equally attracted to the smell of limburger cheese and human feet?
The Ig Nobel Prize ceremony is a festive occasion, with many attendees dressed in costume. The Ig Nobel Prizes are awarded by Nobel Prize laureates. Each winner is given one minute to give her or his acceptance speech and the time limit is enforced by an eight-year girl who acts as the mistress of ceremonies.
An Ig Nobel Ornithology Prize was awarded this year. I think this research provides a great example of how good science can have a humorous side. That prize was awarded to Ivan Schwab and the late Philip May for their work exploring and explaining why woodpeckers don’t get headaches.
Schwab is an opthalmologist and hence a medical doctor, not an ornithologist. May came from a similar medical background. Their work was not published in ornithological journals but rather in medical journals. Two articles were published in the highly regarded British medical journal, the Lancet, and a more recent article in the British Journal of Ophthalmology.
As we all know, woodpeckers use their bills to forage for food, to excavate roosting and nesting sites in trees and to communicate with other members of their species by drumming on a resonant tree or perhaps a gutter on your house. Schwab and May studied the hammering behavior of Pileated Woodpeckers.
Consider the stress the heads of these birds must endure. A Pileated Woodpecker may hammer 20 times in a one second and 12,000 times per day. Each hammer ends with a strong deceleration, equal to 1,200 times the force of gravity. That’s a sudden stop! Schwab points out that that force would be like you running into a solid wall at 16 miles per hour – face first.
So what sort of adaptations do Pileated Woodpeckers have that allow them to avoid massive headaches? First, the skull is strong, and thick with spongier bone found where the skull joins the neck vertebrae. Flexible cartilage is found at the base of the bill to act as a shock absorber, cushioning some of the force of the hammering.
The brain of a woodpecker fits very tightly within the skull with very little cerebrospinal fluid present. That arrangement contrasts with a human brain where our brain is more loosely situated within our skulls, bathed in cerebrospinal fluid. Humans sometimes suffer contre-coup (brain bruising) injuries following a blow to the head. The head stops moving but the brain doesn’t. Woodpeckers do not have to worry about such brain bruising.
Using high-speed videocameras, Schwab and May showed that Pileated Woodpeckers contract powerful muscles that connect the bill to the skull only a microsecond before impact. These contracted muscles spread the force of the impact to the posterior and base of the skull, bypassing the brain.
The woodpeckers also strike with their bill exactly perpendicular to the tree, preventing concussions or tearing of the membranes that surround the brain.
In addition to an upper and lower eyelid like we have, birds have a third eyelid called the nictitating membrane that offers additional protection to the eye. It closes horizontally. In woodpeckers, the nictitating membrane closes just before bill impact. The membrane certainly protects the eyes from flying debris but also literally keeps the eyes from popping out of the head as the woodpecker hammers.
Visit the Ig Nobel Prize website at: http://www.improb.com/ig/ to find more details about Schwab and May’s research.
[Originally published on October 30, 2006)