Listen up if you hear the drumming of a woodpecker

Most people with an interest in birds are aware of the exciting news that about a decade ago great spotted woodpeckers arrived in Ireland and that since then they have been breeding and spreading. 

Genetic studies carried out in UCD indicate they almost certainly came from Britain, where the population of this woodpecker has been increasing rapidly in recent times.

The experts don’t agree on whether this is a colonisation or a re-colonisation. My own opinion is great spotted woodpeckers were once an Irish native species and the last ones probably lived in west Munster in the 17th century. I believe they became extinct when the planters cleared the great forests.

When they came back it looks as though they did so in two groups, one establishing itself in Co Down and the other in Co Wicklow. This happened at some time between 2005 and 2007. Since then they have prospered. There are now confirmed reports from at least 10 counties, mostly in the east and south of the country, and the national population is probably 50 to 80 breeding pairs.

They are a spectacular bird, boldly patterned in black and white with some patches of scarlet, which vary according to age and gender. They’re about the size of a mistle thrush and have a slow and undulating flight pattern with noticeably broad wings. Despite being so distinctive, they’re usually hard to spot. They are shy and spend a lot of time concealed by foliage as they forage for insects hidden in tree bark.

However, at this time of year they start doing something that immediately betrays their presence — they start to drum. They prefer to do this on a dead tree branch, and if it’s hollow as well they get extra resonance. They hammer at the wood with their beak, producing short bursts of noise which, in the right weather conditions, can be heard a kilometre away. Each burst only lasts a second or two but can contain up to 30 strokes.

Drumming usually starts in February and ends some time in April. For some reason it’s commoner in the morning than the afternoon. It’s probably a means of proclaiming a territory and finding a mate. However, it may have another function. Woodpeckers nest in holes that they bore in trees.

They peck horizontally through the sapwood and then vertically down through the heartwood to a small brood chamber lined with wood chips. When they drum they may be using the sound waves to assess the nature of the heartwood, looking for something soft, possibly partly decayed, that will make it easier to excavate the nest hole.

If you hear a woodpecker drumming please inform BirdWatch Ireland to help monitor the success of this new arrival.