Question to the Department for Environment, Food and Rural Affairs:

To ask Her Majesty's Government what assessment they have made of the impact of low concentrations of anti-depressants on the courtship and breeding of starlings.

The experiments conducted by University of York in collaboration with the Animal and Plant Health Agency (APHA) demonstrated that exposing starlings to a maximal environmentally relevant concentration of an anti-depressant (fluoxetine) altered courtship behaviour in wild-caught starlings (Sturnus vulgaris). The males sang less and were more aggressive towards females that had been dosed with an anti-depressant than to the untreated females and in addition the treated females were also initially more aggressive towards males than the untreated females. However there were no effects on female courtship behaviour or on circulating female hormones in treated females. These findings suggest that exposure to this dose of anti-depressant reduced female attractiveness to the male but the reasons why are not clear. Whether these levels of anti-depressants in the environment would have a significant effect on an individual’s fitness or the population as a whole requires further investigation.