The deeper you get into pigeons, the more complicated they get. Are pigeons the same as doves? What are squab and what are quail? Which may you eat, which may you feed, and which may you shoot? It seems to depend on where you live. If pigeons spread disease, why are so many allowed in Venice or at Trafalgar Square? And why does it matter anyway?
The easiest question to answer is that there are over 300 members of the Columbidae family in the world and that quails belong to the Phasianidae family. I once tried to order pigeon in a country whose language I could not speak and was indignant because the pigeon they brought was so tiny, until it was explained to me that I had ordered quail. Squab, incidentally, describes a young pigeon, typically under four weeks old, raised for its meat, which is tender, lean, red, tastes like duck, and is considered fine dining.
Turning to Columbidae, this family has over 300 legitimate members, including pigeons and doves, which are one and the same. There is no scientific or taxonomic basis for distinguishing one from the other except perhaps a conventional understanding that doves are smaller, weigh up to half a pound and have longer tails, whereas pigeons are supposed to be larger, sturdier, and weigh up to as much as nine pounds. Pigeon is a French word derived from the Latin, whereas dove is ultimately of Germanic origin. Both names, used interchangeably in this presentation as pigeons, denote birds with small heads, relatively short necks, stout bodies, and slender bills. The name “dove” has been said to denote a pigeon with a good PR agent.
The biology of these birds is interesting. They can beat their wings extremely rapidly, can maintain a heart rate of 600 beats per minute, when “eating” are in fact collecting food into their esophagus and digest it later, and have no gall bladder but secrete the bile directly into the gut. Females lay two eggs at a time. Both males and females produce milk for their young, called crop milk, which is very high in protein.
Pigeons can adapt themselves to almost any environment other than the Sahara and the Antarctic. They are great at finding their way by a mechanism not fully understood but seems to be an internal compass based on the Earth’s magnetic field. They can fly at altitudes of 6,000 feet at an average speed of 70–90 miles per hour.
Pigeons can carry disease but may also confer health benefits. Historically, they have gladdened the hearts of many with good news. It was a dove or pigeon that brought Noah the good news that the waters of the Flood were receding. Doves have often been regarded as symbols of peace. Carrier pigeons, as occasional bearers of secret messages, have been known to fall into the wrong hands, such as in Jules Verne’s Mathias Sandorf, where the conspirators working for Hungarian independence were betrayed and apprehended.
In ancient Egypt, physicians prescribed pigeon blood for eye ailments. Hippocrates recommended eating pigeon meat as a cure for various diseases. Poultices made from pigeon droppings were used in the Middle Ages to treat skin disorders. During both World Wars, carrier pigeons transported critical medical information and blood samples between field hospitals and medical centers, saving countless lives.
Pigeons have contributed to modern medical research. They have been trained to identify cancerous tissue with high accuracy, even surpassing human performance. Because of their high visual acuity, they have even been trained to identify suspicious masses in mammograms. Their soothing appearance has led them to be used to treat various psychological conditions, addiction disorders, and developmental disabilities.
But pigeons can also present dangers to health. Their droppings can harbor fungal spores. Exposure to dried pigeon excrement, particularly in enclosed spaces like attics or abandoned buildings, increases the risk of fungal pneumonia, in particular Cryptococcus neoformans and Histoplasma capsulatum. Pigeons can transmit salmonellosis, St. Louis encephalitis, and bird mites that may cause skin irritation and dermatitis.
Pigeons can also host Chlamydia psittaci. This is the cause of psittacosis, a bacterial zoonotic infection. It is also known as parrot fever and is transmitted from infected birds to humans. Its known history dates back to the late 19th century, to 1879 in Switzerland, when a group of people who had contact with infected parrots developed a severe respiratory illness. A major pandemic occurred worldwide between 1929 and 1930, linked to the importation of infected parrots from Argentina to the United States and Europe. There were thousands of cases, and hundreds died. In 1930, French researchers identified the bacteria responsible for psittacosis as Chlamydia psittaci.
After the pandemic, research into psittacosis intensified. Antibiotic treatments were developed, and regulations were established to control the import and trade of infected birds. Yet sporadic outbreaks of psittacosis still occur worldwide. The disease is most commonly found in individuals who have had direct contact with pet birds, such as parrots, parakeets, and cockatoos. It is transmitted through contact with infected birds or by inhaling dust contaminated with dried droppings and characterized by flu-like symptoms and pneumonia.
Modern public health approaches consist of balancing human protection with pigeon population management. Rather than eradicate the birds, many cities use birth control with substances such as Ovo Control, which contains nicarbazin to reduce egg viability. Architectural modifications, including netting and spikes, deter birds from nesting in sensitive areas, such as hospitals, without harming the birds. In many parts of the world, medical facilities are required to implement regular cleaning protocols for areas with pigeon activity to minimize the risk of infection. It is recommended that workers handling pigeons or cleaning areas with their droppings should use protective equipment, and the public should be educated about the dangers of contact with these deceivingly innocuous friends of man.