Now is the time the trees begin to take a hammering as great spotted woodpeckers establish their territories.

These starling-sized black and white birds don’t have a song to advertise ownership of their chosen patch of woodland, so they make themselves known by drumming on dead trees with their powerful bills.

It’s a dramatic sound and some creative individuals will use other surfaces such as the metal plates on telegraph poles to create an even louder salvo. One bird even used a metal public address tannoy at a racecourse.

Woodpeckers ought to get headaches as a result of those hammering blows; they don’t because their skulls are cushioned by a matrix of minute pockets of air, supported by strengthened bone tissue.

This natural shock absorber allows them not only to drum, but to excavate nest holes and peck in dead wood for insects. They’re not averse to taking the eggs and nestlings of tits and other hole-nesting birds.

Drumming is most intense between late January and April and you are more likely to hear it at this time of year.

We take it for granted that the woodpecker makes the sound by striking the surface of a resonating object, but as recently as the 1940s, some people still maintained that the bird made the sounds vocally.

The argument was finally resolved in 1943 when a birdwatcher named Norman Pullen settled the matter by placing a microphone inside a tree and watched the woodpecker as its bill struck the bark: the sounds matched the striking exactly.

Great spotted woodpecker populations have increased rapidly over the last 40 years, more than doubling their numbers. They have even crossed the Irish Sea, breeding in Northern Ireland in 2006 and the Republic of Ireland in 2009, for the first time.

Garden feeding may have helped their increase, and the decline of starlings in woodlands has allowed them a wider choice of nest holes. Now you can hear their loud drumming and distinctive ‘chik’ calls over most of the British Isles.

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Illustration by Mike Hughes