Dunnock
Prunella modularis
Dunnock
Creative Commons - credit smalljim
Dunnocks are common, if overlooked, in gardens and woodlands at Rannoch. In fact they are found throughout the British Isles except for Shetland and were even introduced into New Zealand in the 19th century during the misguided acclimatisation policy. This policy involved introducing many European birds to New Zealand to make the settlers feel at home. It has been to the detriment of the native birds. Dunnocks are now common in New Zealand.
The Dunnock is also know rather misleadingly as the hedge sparrow. It’s misleading because the species is not a sparrow but is an accentor. It is the only British accentor but there are 14 species of accentor across the world.
You may think of the Dunnock as an insignificant sulking sort of bird that creeps about semi-hidden in the undergrowth, but its retiring and modest demeanour conceals a sexual tiger. The male has the largest testes in proportion to body size of any British bird and both sexes indulge in a level of promiscuity that puts bonobos in the shade.
The females are polyandrous (mate with lots of males) and the males are polygamous (polygyny - mate with lots of females). This explains the large testes. If lots of mating is going on then lots of sperm are needed and big testes are needed to produce the sperm. It’s all very logical. The complications don’t end there. Some pairs are monogamous while sometimes there is a foursome with two males and two females. To cap it all before mating the males try to remove the sperm of other males by pecking at the females cloaca (the single excretory and reproductive orifice of birds). This amazing behaviour was discovered by Nick Davies working in the Cambridge Botanical Gardens.
I think the female could reasonably be described as ‘long-suffering’.
Creative Commons - credit Arend Vermazeren
You may not have suspected that the goings on in your shrubbery were more like the goings on in Sodom and Gomorrah.
If you take the time to look closely at the next Dunnock that you encounter you may well detect a glint in its eye.
The Dunnock feeds on all sorts of small invertebrates and as it creeps on the ground looking for them it flicks its tail and wings. It is sometimes known as a ‘shuffle-wing’.
The Dunnock is one of the unfortunate species that act as host to cuckoos and those cuckoos that fool dunnocks into looking after their young are able to mimic the look of the pure blue Dunnock egg. Cuckoos are what is known as brood parasites -
Link to a Daily Mail article showing a Dunnock feeding a much larger cuckoo chick. The article features a photo by Alan J Leeks which won the overall prize in the Essex Wildlife Photography competition for 2017. It is a remarkable photo showing the adult Dunnock perched on the back of the much larger cuckoo chick in order to feed it.