Prozac has negative effect on bird population, finds study

The antidepressant not only affects starlings’ food habits but also their interest in mating

By Priyanka Singh
Published: Wednesday 22 October 2014


Increasing consumption of anti-depressants by humans is affecting bird populations, according to a recent study. The drugs find their way into the food chain of other species through sewage and effluent. 

During the study, starlings were kept in cages and fed Prozac-laced worms. It was found that the birds  suffered loss of appetite and even interest in mating. These side effects could be affecting the starling population, says Kathryn Arnold, researcher with University of York’s environment department.
 “Females who’d been on it [Prozac] were not interested in the male birds we introduced them to. They sat in the middle of the cage, not interested at all,”

Arnold told the Guardian.
Arnold began by observing birds flocking to feed on worms and invertebrates at a sewage works.

 “I started thinking, ‘What about what’s in the sewage?’ If you or I take a headache pill for instance, a high proportion of it ends up being excreted completely unchanged,” she told Radio Times.

Arnold measured the level of Prozac present in earthworms living in sewage. It was tiny, around 3-5 per cent of the average human dosage. The 24 captive birds were fed worms containing the same concentration of the drug and Arnold monitored their behaviour for over six months.

“The major finding was a loss of appetite. Compared with the control birds, who hadn’t had any Prozac, they ate much less and snacked throughout the day. The problem then is that they’re less likely to survive long, dark winter’s nights,” The Guardian quoted her as saying.

BBC Autumnwatch presenter Chris Packham was quoted saying, “This change in behaviour could impact negatively on their ecology. We know for instance we’ve lost 50 million starlings in the UK since the 1960s.”

Earlier this month, in a similar study it was found that medicines that get flushed into the environment through sewage might be the reason for the rapid decline in wildlife population. The study team included Arnold.

The 2014 Living Planet report recently warned that the global animal population has more than halved in the past 40 years; and now studies by scientists who attended the seminar reveal that common medicines are harming animals.  

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