Pigeons contain clues to pollution
They have been maligned as ‘‘rats of the sky’’, a filthy menace blighting our cities. Could it be, though, that far from spreading illness from above, pigeons may save us from it?
That is the contention of an American scientist who believes that feral pigeons could be a frontline weapon against a genuine airborne risk: pollution.
Stored in the feathers of each pigeon is the accumulated grime of the cities we share with them. As they peck at our discarded soggy chips and splash through the puddles of our gridlocked streets, they pick up a record of the pollution to which we are also exposed.
Rebecca Calisi-Rodriguez, from the University of California, Davis, has conducted studies showing that the lead levels in pigeon feathers correspond to the lead levels in children living in the same area. They also correlate to the amount of traffic in the vicinity.
Speaking at the annual meeting of the American Association for the Advancement of Science in Austin, Texas, she said she thought that the birds were a perfect tool for sampling polluted urban environments.
‘‘Pigeons have existed for ages in close proximity to us, eating the same food, drinking and being exposed to the same water sources, soil, air, pollution,’’ she said. ‘‘They have a very small home range, spending their life within a few neighbourhood blocks. This offers up the opportunity to not only find toxin hot spots in our environment, but to understand how these toxins affect biology.’’
In 2016, racing pigeons equipped with backpacks were released into London’s skies to take pollution readings across the capital. Calisi-Rodriguez has taken this further, conducting largescale trials on pigeons in New York, looking to see how readings taken from them correspond to the pollution affecting the humans who walk among them.