Dunnock: bird song and calls

By James Duncan

Communities and Wildlife Officer

Dunnock (Prunella modularis)

The Dunnock, an overwhelmingly inconspicuous bird that in fact very much belies its meek and modest nature. It may come as some surprise to realise the Dunnock is in fact one of Britain's commonest birds - as a comparison there are approximately a third as many Dunnocks as there are Robins, though they're certainly not as visible. There's no doubt the Dunnock is one of our most regular garden inhabitants but it's unlikely to be spotted on a garden feeder, for it is a skulking bird of the understory. The population of the Dunnock has actually declined in recent years, particularly during the last part of the twentieth century, and it's currently an 'Amber-listed' bird of conservation concern. Outside of the breeding season the Dunnock tends to draw little attention to itself, creeping and hopping, nervously mouse-like, and somewhat apologetically amongst the shrub-layer. Considering its secretive habits, it has obtained a surprisingly large number of vernacular names, the most common of these undoubtedly 'Hedge Sparrow.' Not only has it suffered the indignity of being incorrectly known as a 'sparrow', its forever struggled to shake this moniker. In fact, it wasn't until the nineteenth century that the ornithologically correct 'hedge accentor' was proposed, though never really caught on. The Dunnock does indeed belong to a continental family of montane birds (the Accentors - Prunellidae) and not to the finch-like Sparrows. Though Dunnock had been proposed centuries beforehand, it wasn't until the 1950s it became universally accepted. Sadly, 'Dunnock' is perhaps not entirely complimentary as it translates to 'dingy-brown diminutive.' 

The naming is just one way in which we've forever misunderstood the Dunnock. Long considered a bird of 'few striking attributes', this was flipped on its head when its breeding habits began to be studied. It turns out the Dunnock has one of the most elaborate mating systems amongst our birds. It subscribes to each and every system of polygamy. One male may have two or more females (polygyny), one female may have two or more males (polyandry) and two or more males may share two or more females (polygynandry) - truthfully this only scratches the surface of the real complexity. The Dunnock has an extraordinary private life, its lusty behaviour resulting in copulation that may occur hourly for days on end (though it is brief!) Ultimately there are of courses strategic benefits in their choices, with broods fed by multiple birds potentially assisting survival. Indeed, it isn't just breeding habits that are complicated, Dunnock vocalisations exhibit the same complex nature. 

It's likely the Dunnock will be one of the first birds to sing early in spring, quickly recognising the light of the lengthening days. It may not be the very first to join the daily chorus, perhaps delayed by its proclivity for 'nocturnal activities.' However, the breeding season is the one time of the year when the Dunnock breaks free from its stealthy nature and begins to sing from prominent song-posts. This may typically be a low tree or bush and it'll often sing repeatedly from the same position before shooting off into cover. They're not entirely limited to breeding season song and will be heard year round, even in winter, when males sing to defend their territories, though they'll be less visible. Look and listen out for their 'twiddly' fluctuating song as it shuttles back and forth relatively close to an even pitch.

Listen to the song in this video below -

The Dunnock's song is a somewhat squeaky little ditty, usually lasting for between 2-4 seconds per verse. It's certainly not a song with significant vocal range and has a quick, but meandering, consistently paced quality. It's a warble of sorts, remarkably clear and surprisingly loud, though it lacks the explosive intensity and variety of Wren song. One could say it's a little tuneless, very difficult to transcribe, as the cascade of notes stumble into each other. Though it may not be the richest to human ears, it's certainly a complex system of communication, in much the same vein as the mating habits. The males have a surprising range of song and are renowned for copying the songs of their Dunnock neighbours, incorporating them into their own. A study by celebrated Ornithologist D.W Snow in 1983 hypothesised a number of reasons for this, one being that a Dunnock may give a false impression of a territory occupied by many individuals in order to deter intruders - as a whole the reasons continue to remain unclear. Interestingly, vocalisations related to sexual selection may not be limited to the males, as a study from the University of Cambridge in 1996 indicated increased vocalisation amongst females when competing strongly for males.

The Dunnock exhibits a call that tends to serve a number of functions, including a regular contact call, an alarm call and as a display call. It's a monosyllabic and strongly uninflected 'piping' note, transliterated as "tiiih." It's often likened to a 'squeaky wheelbarrow' or gate. It certainly has a pure quality, and may either be uttered as an individual note or as a shorter but more insistent ringing sequence, where it serves as the alarm. When rival males clash in dispute, much calling and wing flapping/flicking may ensue.

Listen to the call below -