In the paper recently there was a letter espousing the idea that an increasing number of badgers were having a detrimental impact on the populations of farmland birds.

Certainly, badgers will eat birds’ eggs. However, the major cause of decline in farmland birds in arable southern UK, particularly those relying on insects for food, is the huge decline in insects as a result of the ongoing use of agrochemicals, particularly insecticides and pesticides.

This, along with climate change and loss of habitat, was identified as the main cause for the decline in farmland birds in the RSPB’s State of Nature 2016 report, based on objective ­scientific evidence.

With respect to insects, one only has to look back to the 1960s, when at dusk windscreens and radiator grills would be covered in dead insects and moths drawn to the vehicle by the headlights. That doesn’t happen today.

While the loss of many species of insect is not always noticeable without scientific monitoring, it is very clear to the layman that the numbers of butterflies have declined. Consequently, there is less and less food available for insect-eating birds.

Some species of warbler – many of which rely on insects – such as the willow warbler no longer breed in the South Hams. However, if you go north of Liverpool, Manchester and Leeds, numbers are increasing in the hill country ‘up north’, where insecticides and pesticides are seldom used.

Similarly, if you go to France, where there is less intensive farming, there has been little or no decline of insect-feeding birds.

Additionally, climate change is impacting on many species of wildlife, resulting in their breeding ranges steadily moving north. Marine animals from the Mediterranean are now being found in the southern North Sea; insects, such as crickets, bumble bees and moths from further south, are colonising southern counties of the UK, while species of heron, such as little egret, purple heron, cattle egret etc, are ­moving into the UK from France and breeding.

Farmers are wary of scientific evidence that points the finger at them – after all, they know their patch better than anyone else.

While this may be true, they don’t necessarily see the wider picture, as viewed by objective scientific enquiry, and they have constantly been encouraged to provide the nation with cheap food.

That our windscreens and radiator grills are no longer covered in dead insects at dusk is surely very visible and tangible evidence that they are in serious decline, and as a result so are those species of bird that rely on them for their survival.

Dennis Elphick

Gidleys Meadow, Dartington