- Scientists’ fears after birds use plastic litter to build their nests
They are a mainstay of the Scottish countryside, delighting people as they flit from branch to branch.
However, plastic pollution could kill the next generation of blue tits.
Scientists have discovered that blue tits occur Glasgow use 50 times more artificial waste to make their nests than their rural cousins on the banks of Loch Lomond.
Research has shown that chicks are less likely to survive if their first days are spent among waste such as nets and tennis ball fibres.
Moss and grass are essential for successful fledging of chicks – but such natural litter is becoming increasingly scarce as birds breed in urban areas.
The numbers of blue tits have decreased significantly in recent years
Plastic in nests can affect the health of chicks
Now there are fears that plastic pollution could contribute to population decline, which has seen the number of forest birds fall by more than a third in fifty years.
A spokesperson for RSPB Scotland said: ‘Every year we see litter being used as nesting material.’
Dr. Viola Ross-Smith, science communications manager at the British Trust for Ornithology, said: ‘Any finding of adverse effects from anthropogenic activities on our wildlife is worrying.’
Last year, researchers from the University of Glasgow identified 64 blue tit nests, of which 31 were found at six locations in the city and the other 33 were recovered in woodlands on the east coast of Loch Lomond.
They were all taken to the laboratory for analysis once all the chicks in them had fledged.
All contained a mixture of natural materials, but almost three-quarters were built partly with human waste – a figure that rose to 90 percent in nests that had been located in the city.
Recent UK government statistics show that blue tit numbers have shrunk by a sixth between 2016 and 2021.
