Songbirds altered their courtship behaviour after exposure to antidepressants increasingly found in the natural environment, according to a three-year study conducted by British scientists.
Male starlings sang less and were more aggressive towards females that had been given small doses of the antidepressant Fluoxetine, commonly known as Prozac, researchers at the University of York found.
They believe the study shows such changes in behaviour could put songbirds at risk in the wild.
“Here is the first evidence that low concentrations of an antidepressant can disrupt the courtship of songbirds,” said Kathryn Arnold, from the university’s environment department.
“With many wildlife populations in decline, we have to ask whether more could be done to remove chemical contaminants like pharmaceuticals from our sewage.”
River systems around the world are coursing with waste from over-the-counter and prescription drugs that harms the environment, according to the European Geosciences Union conference held in Vienna in April.
If trends persist, the amount of pharmaceutical effluence leaching into waterways could increase by two-thirds before 2050, it was reported.
In Britain, 64.7-million antidepressants were prescribed in 2016, the York study noted.
Human pharmaceuticals enter the environment via sewage and contaminate birds foraging on invertebrates at wastewater treatment plants. The scientists tested the effect on starlings, a species commonly found feeding at such sites.
The most visible results emerged after they paired males for two days with a female that had been dosed with Prozac.
Researcher Sophia Whitlock said: “Males sang more than twice as often and as long to untreated females compared to females that had been receiving low doses of Prozac.”
Instead of courting them, males were more likely to chase, peck or claw the female starlings on Prozac.
“Our findings suggest that exposure to an antidepressant reduced female attractiveness,” the study’s authors wrote. — AFP