P is for Pied Wagtail

PIED WAGTAIL (MOTACILLA ALBA)

 The dainty pied wagtail is a common and regularly seen across the country. This little bird brings a sprightly charm to our city streets. 

With their pied plumage and long tail, pied wagtails look a bit like a miniature magpie  Pica pica (some people unfamiliar with birds believe they are baby magpies). Male pied wagtails are truly black and white, whilst females have a grey wing mantle. As their name suggests, they almost constantly wag their long tail up and down. Nobody knows exactly why they perform this eccentric behaviour, but hypotheses include signalling to other wagtails, signalling their alertness to predators, providing camouflage against running water (which most wagtails are associated with), as a still silhouette would stand out against a moving background, or to startle their insect prey out of hiding¹.  People likened this streamside bobbing to a maid scrubbing washing in the river, giving it the local names “Polly dishwasher” and similar².

Pied wagtails get around by walking with bursts of zippy, skittering dashes, so fast their legs are a blur to our eyes. Their repetitive call is a spontaneous “chi-ssick” sounded from the ground or in bounding flight. Males also have a rambling song, which is rarely heard.

Of all our wagtails species*, the pied wagtail is the least associated with water. Though they are often found in wet places, they also prefer wide, open areas where they can easily pick out their prey on the ground and spot potential predators. Paved and tarmacked surfaces are ideal, and pied wagtails have taken well to our streets and car parks. Our cars provide an added bonus, as they will pick the squashed insects off number plates. 

Though they are mainly insectivores, pied wagtails are always grateful for a handout of crumbs. The only time a wagtail was encouraged into our garden was last year’s snowy winter when it fed on the crumbs of our fat balls, and in Falmouth, Cornwall there is a male wagtail missing a foot, who seems to make his living and feed his chicks on Cornish pasty crumbs.

After a frantic day feeding on the ground, wagtails gather to roost in a tree or other perch. These mass-roostings are a magical spectacle, with trees festooned with feathery bundles like a Christmas tree (in fact they often use town Christmas trees). They gather on the ground, roofs and nearby perches before circling into the roost together with a cacophony of excited chattering before they all settle down. These roosts may number hundreds or thousands of wagtails. The largest recorded, in a Kentish reedbed, held 5000 birds³!
Though they don’t physically huddle, these gatherings may create a warmer microclimate to help the small birds survive in cold nights. They often choose to roost under the warm glow of a street light or sometimes in greenhouses on hot water pipes³.  

As with many resident British Birds, numbers of pied wagtails are swelled by migrants from the North in the winter months. During this season when food is scarce, adult male pied wagtails are territorial, whilst females and subordinate males forage in flocks. Though sometimes the males tolerate another ‘satellite’ wagtail in their territory who helps to defend it ⁴.
Another rarer visitor on migration is the White Wagtail Motacilla alba alba, actually a sub-species of the pied wagtail from mainland Europe. It is similar to a female pied wagtail, but with paler grey wings and other slight plumage differences. 

Pied wagtails nest in crevices, often in old stone structures such as old walls and tiled roofs and will use open-fronted nest boxes. Their small, cup-shaped nest is made of grass and moss. When the juveniles fledge, they are mainly a grey-brown with black throat and wing markings until their second year. Pied wagtails are typically short-lived, but the oldest recorded was 11 years old⁴.

This little city slicker is a delight to have around, and next time you’re on the streets on a Friday night, it just might be worth looking up at the trees.

*The others are the Grey Wagtail M.flava and the migratory Yellow Wagtail M.cinerea

 References

1-      Dominic Couzens. (2012) Garden Birds Confidential. Bounty Books.

2-      Fransesca Greenoak. (1979) All the Birds of the Air. A. Brown and Sons.

3-      Michael.J. Seago (no date) Pied Wagtail. Birds of Britain. Available from: http://www.birdsofbritain.co.uk/bird-guide/pied-wagtail.asp

4-      R.A. Robinson.(2005) BTO BirdFacts: profiles of birds occurring in Britain & Ireland: Pied Wagtail Motacilla alba   [Linnaeus, 1758]. Available from: http://blx1.bto.org/birdfacts/results/bob10200.htm