This week's report that Iran had found "spy pigeons" near one of its nuclear faculties looked ridiculous. The very idea of using pigeons for intelligence gathering is obviously crazy. But is it crazy enough to be true?

Attaching instrumentation to pigeons easier than you might think. Beatriz de Costa attracted attention in 2006 when she started using instrumented pigeons for air quality monitoring in California. The birds are equipped with GPS and a stripped-down mobile phone and camera as well as a device to measure air pollution, and send back data via SMS texting – they have their own blog. (Da Costa is an Associate Professor at the University of California, Irvine "Departments of Studio Art, Electrical Engineering and Computer Science" and described as an "interdisciplinary researcher and artist.")

De Costa is using commercially available hardware; intelligence agencies can probably get the same capability in a much smaller package. Pigeons have long been used by intelligence agencies because they can get a message through when no other means will work. The Iraqis reportedly used pigeons in the 1991 Gulf War as a means of circumventing radio jamming ; the Swiss Army did not terminate their carrier pigeon program until 1994.

Da Costa was actually inspired by German engineer Julius Neubronner who experimented with camera carrying pigeons in 1903 – an idea apparently later taken up by German Military Intelligence.

(The U.S. military used pigeons until 1957, long enough for pigeon-based equipment to be given its own communications system designation, such as AN/CBQ-1 for the "Air-transportable Pigeon Loft & Message Center." Some pigeons won medals for their services; the bird Cher Ami earned the Croix de Guerre for saving the lives of many U.S. soldiers during World War I. Britain's PDSA animal welfare organization awarded the Dickin medal "for conspicuous gallantry and devotion to duty" to 32 pigeons over the years.)

Pigeons are still useful in the modern age. Earlier this year, criminals were found to be using carrier pigeons to smuggle drugs and mobile phonesinto a prison in Marilia in Brazil. Kidnap gangs in Iraq reportedly used pigeons to collect ransom.

What about intelligence agencies? Back in the 1960's, the CIA experimented with "Acoustic Kitty," a cat wired up to record conversations. And just last year, Chinese scientists reported having implanted electrodes in a pigeon's brain "so they can command it to fly right or left or up or down." Darpa has performed similar experiments with sharks. So perhaps a GPS-enabled pigeon might be guided to a specific location.

Though bizarre, expensive and not very practical, pigeon spies may well be possible. But you have to look at more prosaic explanations, too.

Racing pigeons are popular in Iran. There are several native breeds, collectively known as Iranian Highflying Tumblers, that are bred for endurance and aerobatic somersaulting.

So a pigeon with a metal ring on its leg – like this week's alleged spy bird – should not just be such an extraordinary sight.

Perhaps the Iranians will copy the approach used by British counterintelligence during WWII. The Army Pigeon Service Special Section employed two peregrine falcons to intercept pigeons released by German spies with some success.

And you thought the spy pigeons were fiction…

[Photo: NASM]