Urban Pollution and Great Tits

Is it time for some citizen science?

By Annette J Beveridge

With towns and cities expanding, many animals find themselves having to live in urban areas and this includes a popular garden bird – The Great Tit.

In rural life, there may be fewer natural predators, but there is a greater risk for these birds and other animals when it comes to coping with the pollutants of urban life and the key changes in their diet.

Great Tits are adaptable birds and therein lies much of their success and they capitalise well by using garden feeders. Due to their readiness to use nest boxes and to be around people, they have become popular birds to study. But not all is rosy in the Great Tit world.

Research indicates that the animals living in cities are less vibrant in their colouring and display a much duller  yellow, orange and red colour tones… in comparison to non urban counterparts.

Great Tits are known for the bright splash of yellow across the chest and belly. The yellow in the feathers comes from carotenoids obtained from the insects they eat. The insects gain these nutrients  from eating plants.

Carotenoids are important antioxidants which help the body to combat the toxic impact of pollution. If the birds are unable to gain sufficient levels from their food, plumage becomes paler, and there is a weaker defence against pollutants.

It is worth finding time to observe Great Tits in your garden or at local parks. How vibrant is the yellow colouring? Distinctive looking, and the largest of the UK’s Tit family, it is concerning that natural defences may be weakening.