This was a puzzle and attempts to make the power lines more visible failed. Apparently the answer is that birds have blind spots in their field of vision that make the power lines ‘invisible’ to them, due to the way they have evolved to become successful foragers.

Although the heavy bustard differs greatly in general body shape from the delicate crane and stork, the birds share a foraging technique – visually guiding their bill to take food items.

This technique requires excellent vision at the end of the bill, resulting in a narrow field of vision and wide “blind spots”.

“Once we saw the wisdom of looking at the problem through birds’ eyes rather than human eyes, it all made sense,” says Professor Graham Martin.

“These birds can see straight ahead in flight but they only need to pitch their heads forward by a small amount and they will be blind in the direction of travel.”

Many species of bird have been observed looking down during flight, possibly to locate fellow birds and suitable foraging and nesting sites.

Narrow binocular fields combined with birds’ tendencies to look down effectively means certain species cannot see power lines until it is too late.

It is sad that there seems to be nothing we can do about it.