Prunellidae – Accentors

The Prunellidae (Accentors) are the only bird family, which is endemic to the Palearctic. This small group of closely related passerines are all in a single genus – Prunella. (Although the Alpine Accentor and Altai Accentor used to be separated into the genus Laiscopus by some taxonomists.) All but the Dunnock and the Japanese ccentor are inhabitants of the mountainous regions of Europe and Asia; these two also occur in lowland areas, as does the Siberian Accentor in the far north of Siberia.

Their typical habitat is mountainous regions in an area far above the tree-line, but below the snow-line. The Himalayan accentor can be found as high as 17,000 ft above sea level when breeding, however, most accentors breed in scrub vegetation at lower levels and most species migrate downwards to spend the winter, with only some being hardy enough to remain. This genus is not strongly migratory, but they will leave the coldest parts of their range in winter, as well as making altitudinal movements. Accentors spend the majority of their time in the undergrowth and even when flushed, stay low to the ground until reaching cover.

They are small, often rather drab species generally regarded as being related to the thrushes or the warblers. Accentors have thin sharp bills, reflecting their diet of ground-dwelling insects in summer, augmented with seeds and berries in winter. They may also swallow grit and sand to help their stomach break up these seeds.

Robin Accentor Prunella rubeculoides 

Alpine Accentor Prunella collaris

Most of the species live together in flocks. The Dunnock is an exception since it prefers to be solitary except when feeding. The Dunnock also earned a nickname of “shuffle-wing” since it most strongly displays the characteristic wing flicks used during courtship and other displays.

Rufous-breasted Accentor Prunella strophiata

Their mating systems are unusually flexible, with some pairs breeding monogamously (usually where resources are relatively scarce) and others breeding polygamously, either one male with two or more females (polygyny), one female with two or more males (polyandry), or, occasionally, several males and females together (polygynandry). This variety reflects the fact that males and females defend territories more or less independently.

Black-throated Accentor Prunella atrogularis

Where resources are rich (and hence territories can be small) it is possible for males to monopolise several females, or for females to attract several males. Accentors may have two to three broods a year. Courtship consists of a great deal of song from the males, which may include short lark-like song flights to attract a mate. In most species, the male and female share in the nest making, with the dunnock being an exception – their males have no part in nest building or incubation. They build neat cup nests and lay about three or four unspotted green or blue eggs. Both parents tend to share feeding and rearing of young.

The accentors are mostly birds of high-mountain meadows, fell fields, scrublands, and forest habitats far more extreme than the gardens and hedgerows occupied by the low-altitude Dunnock.

Dunnock Prunella modularis – ©Ashley Beolens

 Details are sparse, but available data indicate that the mating systems of the high-altitude accentors may be just as variable and intriguing as that of the Dunnock; one of the world’s plainest birds to look at, it has every mating system known in passerines in a single species. This mating system, in which males compete for mating opportunities with females and females compete for parental care from males, is a wonderful contrast to those of virtually all other passerine groups and a laboratory for understanding sexual selection in sexually monomorphic birds.