Species of the day: Great Spotted Woodpecker

By James Duncan

Learning and Engagement Officer

The Great Spotted Woodpecker (Dendrocopos major) is undoubtedly the most commonly observed member of its family (Picidae), largely owing to its adaption to urban environments. Its numbers have multiplied significantly in recent years, with somewhere in the region of 140,000 pairs now found across Britain. With an extensive range across the Palearctic, from the Atlantic to the Pacific and from the Mediterranean to the Arctic, it's rather surprising that it's only become evident in Ireland in the last decade or so. Comprehensive deforestation resulted in an Irish demise more than three hundred years back - it's only though natural recolonisation that it can once again be seen there. With its striking pied plumage and infusion of red, it's a rather unmistakable bird and always a pleasure to observe. Confusingly, the red colouration varies in position depending on age and sex. The adult males exhibit a red patch on both the nape (hind-neck) and vent (lower belly - reminiscent of red underpants), whereas the adult females don't have the red nape at all. Contrastingly, the juveniles have a red crown (top of head) which is usually brighter on males, and typically have a paler red vent, but no red nape either. As one of only two 'pied' woodpecker species, the roughly 'Blackbird-sized' Great Spotted Woodpecker is hard to confuse with its relative, the significantly rarer 'Sparrow-sized' Lesser Spotted Woodpecker.

Found extensively within all types of mixed woodland the Great Spotted Woodpecker is as much at home amongst our larger parks and gardens, though it is a highly cautious bird. When spotted, it has the rather amusing habit of rapidly shuffling around to the opposite side of a tree, 'peeking' out to check if it's still being watched. If it does take to the air it'll have the appearance of a feathered dart, arrow-straight with the wings drawn-in between flaps, leading to a characteristic 'bouncing' flight. In recent years it's become a successful beneficiary of garden feeding and may be seen acrobatically hanging from feeders and bird tables, supplementing its omnivorous diet. Away from the feeders, it's a bird that's perfectly suited for an arboreal (tree dwelling) life. Its dagger-like beak is the ideal tool for chiselling seeds from pine cones and insects from within the tree bark. However, it has a further trick up its avian sleeves for its long sticky tongue is the perfect device for extracting prey from those hard-to-reach places. It may seem surprising, but the Great Spotted Woodpecker is also a superb opportunist predator. It'll happily hammer its way into nest holes, and even nest-boxes, to access both the nestlings and eggs of other birds. Vulnerable cavity-nesting species are no doubt having a tougher time with the population increase of Great Spotted Woodpeckers. Their sheer adaptability in both feeding and habitat has ultimately paved the way for their ongoing success. 

Outside of gardens the Great Spotted Woodpecker's skulking habits help it remain elusive, though its vocalisations usually serve to reveal its presence. The most obvious call is a rather abrupt "kick", though the most widely recognised 'song' is that created by 'drumming' upon wood, a critically important component of its breeding behaviour. This will be heard in spring, each rolling 'drum' lasting for around half a second, possibly containing up to twenty individual strikes. Frequency may hold the key, for the number (and timing) of strikes is critical in generating the appropriate resonance within the wood. It can be generated by both sexes and is used predominantly to demarcate territorial boundaries and warn off potential rivals. The most remarkable thing about it is the simply staggering forces generated within the woodpecker's skull. Clearly this is not something to be undertaken lightly, for the percussive power should be enough to generate not just concussion, but brain damage. In fact, it was once deemed so bizarre that it wasn't until the mid twentieth century the drumming was finally established to be a percussive strike, as opposed to a vocal skill. Fortunately for the woodpecker, it's evolved rather wonderful 'shock-absorbers' where the upper mandible of the beak connects to the skull. These help to neutralise the headache-inducing impacts, whilst further skeletal adaptions add strength and narrow nostrils protect against debris. Great Spotted Woodpeckers have also been recorded drumming on man-made metallic objects - the immense protection enabled by their physiology has even made them the subject of studies to reduce the impact of head injuries and to improve the design of protective headgear. 

 

Great Spotted Woodpecker male, and juvenile © Roger Wilmshurst