Why a pigeon struts its stuff
QUESTION Why do pigeons nod their heads every time they take a step?
For many years, ornithologists believed the synchronisation of a pigeon’s head bobbing with the movements of its feet was a biomechanical function, comparable to humans swinging their arms when walking. However, there is strong evidence this bobbing helps the bird’s vision.
In 1978, researchers at Queen’s University in Canada filmed the movement of pigeons on a treadmill in a Plexiglass box and then slowed it down to examine it in detail.
Their results published in the Journal of Experimental Biology overturned the key assumption: Pigeons aren’t bobbing their heads, but are pushing them forward then holding the pose and allowing the body to catch up.
In the so-called thrust phase, the head is pushed forward relative to the body by about 2 in.
This is followed by a hold phase, during which the head is kept still. The human eye perceives this as a bob because the action is so rapid, taking place five to eight times a second as a pigeon is walking.
It was discovered that when a pigeon’s visual surroundings remained static, the animal’s head didn’t bob.
Head thrusting helps pigeons to stabilise their view in a changing environment. Keeping the head still in space gives the bird a moment to visually process its surroundings to see potential food and predators.
Humans have an equivalent visual response called optokinetic nystagmus: rather than keeping the head stationary, the eye fixes on objects in motion. These compensatory eye movements are used when walking, cycling and driving.
Andrew Symonds, London N12.
QUESTION How many airports are named after politicians or celebrities?
OUT of 4,037 scheduled commercial airports around the world, at least 351 are named after a person. Most are politicians, royals or religious leaders. A growing number are named after a musician, actor, artist or sports star while some honour aviators or industrialists.
The only popular figures honoured in the UK are George Best in Belfast and John Lennon in Liverpool.
The U.S. has by far the most eponymous airports with 90.
Most recent U.S. presidents to be honoured include: John F. Kennedy twice, in New York and Ashland Wisconsin, George H. W. Bush, Bill (and Hillary) Clinton and ronald reagan. We’re awaiting obama and Trump airports.
Former Nevada senator Harry reid has an airport named after him at Paradise, Nevada, just outside Las Vegas.
Sporting figures Arnold Palmer and Muhammad Ali, film stars Jimmy Stewart and John Wayne, comedians Will rogers and Bob Hope, musician Louis Armstrong, aviation pioneers Igor Sikorsky and William Edward Boeing and flying aces Francis S.Gabreski and Chuck Yeager have also given their names to airports.
Greece has Alexander the Great, Philip II of Macedon, Hippocrates and Aristotle; Mongolia has Genghis Khan; France has Charles de Gaulle and Corsica Napoleon Bonaparte; Albania has Mother Teresa; Austria has Wolfgang Amadeus Mozart; Brazil has aviation pioneer and national hero Alberto SantosDumont and musician Antonio Carlos Jobim of The Girl From Ipanema fame; Hungary has Franz Liszt; and Israel has David Ben-Gurion.
There’s Ian Fleming airport in Jamaica and Cristiano ronaldo in Madeira.
Palermo in Sicily commemorates Giovanni Falcone and Paolo Borsellino, two judges who took on the Mafia.
Mainland Italy has Christopher Columbus, Marco Polo, Giuseppe Verdi, Caravaggio, Leonardo da Vinci and Guglielmo Marconi.
Just 16 international airports are named after women, including Indira Gandhi in Delhi, Queen Tamar of Georgia in Mestia and actress Maria Montez, the Dominican Queen of Technicolor, in Barahona.
Some have dropped off the list, most notably Saddam International Airport, which is now Baghdad International Airport, and Hamid Karzai International Airport, which has been renamed Kabul international airport.
Sandra Hayes, Chippenham, Wilts.
QUESTION Does anyone still suffer from dropsy and lumbago?
THE term lumbago is too imprecise for modern medicine.
Lumbago is acute or chronic pain in the lower back caused by muscle strain or a trapped nerve. The term comes from the Latin lumbus meaning hip or loin.
Dropsy referred to swelling caused by a build-up of fluid. This symptom of kidney disease or congestive heart failure affects the lower extremities, abdomen or chest cavity.
It was often deadly, so physicians recommended drawing out the fluid to relieve suffering and prolong life.
According to 19th-century author Horatio Goodday, deaths from dropsy might be prevented by ‘good air; suitable clothing and shelter against excess of damp, cold and heat; cleanliness; proper food; exercise; rest; and the right observance of the Sabbath’.
Today we call it oedema from the Greek oidema, meaning to swell. This happens when small blood vessels leak fluid into nearby tissues.
Dr Ian Smith, Cambridge.
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