An avian soap opera

The Dunnock is not what it seems, especially when it comes to mating

The Dunnock has something of an image problem. One of our most common species, it is a bird that is familiar to us all and, because it is so common and so familiar, it is also often a bird that is completely ignored. With its skulking habits and generally unobtrusive manner, the Dunnock isn’t a bird to stand out in a crowd – it doesn’t have the acrobatics of the tits or the colour of a Robin to draw the eye. It is the archetypal Little Brown Job. If there was a television program called Bird Makeover Challenge then surely our humble Dunnock would be a prime candidate for a starring role. The first thing they would probably look at changing is the bird’s name. The main coloration of the bird is responsible for it and its other names. The word Dunnock is derived from an old word that meant ‘little brown one’ (quite simply, it is the original LBJ!) and the alternative name of Hedge Sparrow is again referring to the brown plumage that resembles the unrelated, and altogether more boisterous, House Sparrow. Even the Latin name of Prunella modularis stems from the bird’s colour; Prunella meaning little plum or brownish. The proper name for the Dunnock though, is the Hedge Accentor. The Accentors are a small family of birds, that is the only bird family endemic to the Palearctic region. In total, there are 13 species, while in our part of the region, the Western Palearctic, five can be found as regular breeders. Of these, three, Radde’s, Black-throated and Siberian Accentor are extremely restricted in range, while the more common and widespread Alpine Accentor is limited (In Europe) to the mountain regions of southern and central Europe. The Dunnock is not restricted (although in the Mediterranean region it is more of a wintering species) and is abundant; the British breeding population is estimated to be more than 2.5million pairs. Whether you call it the Hedge Accentor, the Hedge Sparrow or the Dunnock, there is no getting away from the fact that the bird is indeed brown. But, it is not completely brown – the head and neck of the adult birds are in fact a lovely slate grey in colour. When you see this in full sun it makes, in my opinion at least, the bird look very smart indeed. The problem is, Dunnocks don’t often sit out in the full sun, preferring instead to be in among shrubs, or within the hedgerow, and when they do venture out they never go very far from cover. Now, I am a fan of the Dunnock, but based on the evidence so far, even I have to admit that they do indeed seem a bit dull. But the Dunnock has a trump card to play that certainly spices up the bird’s image. Its sex life. That is definitely not dull! The Dunnock is a great example of how we often take our common birds for granted, making assumptions about their lives without ever really looking closely at them. When the Dunnock’s mating strategy was studied by biologists, not only did it reveal that the bird behaved in a very unexpected way, but it also discovered strategies that are very unusual in the bird world. To put it simply, there is no hard and fast rule when it comes to the mating strategy of these

otherwise unassuming LBJS! The last two strategies are unusual in the bird world and, guess what? The Dunnock practises both, but it also practises the first two as well! All four strategies can be, and are, employed by our unassuming garden visitor. Not only that, they will also often switch between them as spring progresses. The most common strategy is that of polyandry, where the female will seek out matings with more than one male, resulting in a brood that has more than one father. It is very much the norm for two different males to share the feeding duties of a single brood of Dunnock chicks. For the female, this is a result; an extra bird helping with the parental care of the chicks will ensure that more of them survive to fledging. But, for the males, the outcome is less than satisfactory. However, they can, and do, try to change this. If the male is able to provision the female with an abundance of food, then the female’s territory reduces significantly. This results in her wandering less and therefore reduces the chance of her mating with another male, but the downside to this is that the male can spend too much time searching for food and not enough time defending his territory, which can result in a male (or even males!) sneaking in and mating with the female. Another tactic employed by the male is that of pecking the female’s cloaca, a process which leads to the female ejecting sperm from a previous mating; the male will then mate with her himself and then try to guard her from other males to try to ensure that he is the sole father of the resulting brood. The life of the Dunnock may at first seem as if it could indeed be the topic of a ‘makeover’ style television program, but in fact, the life of the Dunnock is pure soap opera drama, and what’s more is that it is all going on right under our noses and you don’t even need to pay a licence fee to see it.

It is very much the norm for two different males to share the feeding duties of a single brood of Dunnock chicks