Pigeon 'Whisperers' Use Birds To Track Lead Pollution

A study of pigeons in New York City showed that levels of lead in the birds track with neighborhoods where children show high levels of lead exposure.

The results were published July 18 in the journal Chemosphere. 

"Pigeons share our environment all over the globe, they're exposed to many of the same environmental contaminants as we are and often they suffer similar health consequences," says Rebecca Calisi, assistant professor in the Department of Neurobiology, Physiology and Behavior at the University of California, Davis, who conducted the study with undergraduate student (and study co-author) Fayme Cai while at Columbia University. 

Calisi says monitoring pigeon biology may provide more understanding of the location and prevalence of lead and other harmful toxins, which could lead to the creation of prevention measures. 

"So the data pigeons can provide us also have the potential to, if you will, speak for under-served and socioeconomically challenged communities who might be suffering from environmental pollutants but who lack the voice and means to assess and act," she says. 

Calisi says new studies show even tiny amounts of lead are detrimental to the health of children. 

UC Davis Assistant Professor Rebecca Calisi plans to use pigeons to track pollutant levels in California.  David Slipher / Courtesy 

She now plans to expand the work in several California cities, including Sacramento, San Francisco and rural agricultural areas. 

"Currently we're devising a panel of different pollutants to look at to see what's most prevalent in these areas, what's most feasible to study and this includes other heavy metals and dangerous pollutants such as fire retardants and pesticides," she says. 

In New York City, Calisi and Cai used lead screening records of children taken by the New York City Department of Health and Mental Hygiene, along with blood samples from 825 pigeons over a five-year period (2010-15), to correlate and analyze the levels between the birds and children.

Each pigeon was identified by the zip code where it was found. 

The findings showed the pigeons’ blood lead levels rose in summer, as they did in the blood samples from children.

Calisi says zip codes with high lead levels in pigeons also had some of the highest rates of raised levels of lead in children. 

'Pigeon Whisperers'

While pigeons have been used to monitor various types of pollution in some European cities, Calisi says as far as she knows, no one has previously correlated lead exposure in birds with exposure rates in children.

She says urban pigeons are ideal for tracking pollution in her work because they don’t fly far and typically spend their lives within an area of a few blocks. 

But how do researchers wrangle the pigeons? 

"The scientists in my lab are pigeon whisperers," Calisi joked. 

She explained that food traps or nets are used along with "yummy goodies" to entice the pigeons. 

"When we catch the pigeons, we do a little health assessment, make sure they’re in good condition and we take a blood sample, that’s it," says Calisi.  "And, if the pigeon is healthy enough to be released we let the pigeon go on its way and note where we collected the sample."

The pigeons get a treat, the researchers get their blood, the birds fly away ... and the "rats with wings" play a role in environmental research.