The courtship rituals of birds are being disrupted by human medical products seeping into their habitats, new research suggests.
A study led by the University of York found that if female starlings were exposed to small amounts of antidepressant drugs, they were less attractive to the opposite sex.
Males were less likely to sing to females exposed to fluoxetine, also known as Prozac, and were more likely to be aggressive to them.
The study has raised concerns for birds feeding at sewage plants, where worms, maggots and flies have been shown to contain traces of medical products.
Dr Kathryn Arnold, who worked on the study, said: “Here is the first evidence that low concentrations of an antidepressant can disrupt the courtship of songbirds. This is important because animals that are slow to find a mate often won’t get to breed.
"With many wildlife populations in decline, we have to ask whether more could be done to remove chemical contaminants like pharmaceuticals from our sewage.”
The results of the three year study have been published in the journal Chemosphere.