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

J is for Jackdaw

Jackdaw (Corvus monedula)

It wouldn’t be right to obsess about birds without mentioning a corvid (member of the crow family). Renowned in science for their incredible intelligence and behaviour and in fiction for the folklore they are steeped in.

Of the large, black birds in the genus Corvus, the jackdaw is one of the most recognisable*. It is the smallest of the lot, with a grey bobble head, black cap, pearly white eye and of course it’s distinctive yapping call. They can be found pretty much everywhere except the barren highlands, both as townies and farmland birds, where they are one of the few species benefitting from large intensive fields. They sometimes visit gardens, especially during the breeding season and winter when there is pressure to find food¹.

The Jackdaw’s name attracts a lot of interest since it includes a human one. It is usually explained as imitating their call, but the name is also used to refer to small stature such as the jack snipe (Lymnocryptes minimus).  The ‘daw’ part has a linguistic meaning, referring to ‘someone in low esteem’ possibly due to being common,  and given to thieving precious objects ² (though ‘stealing’ is only practiced by captive corvids).

Like other corvids, jackdaws will eat pretty much anything. Though their stubby beak prevents them probing the soil like other Corvus, it is a powerful tool . I have seen them smashing open conker (Aesculus hippocastanum) shells. They do eat the eggs and young of other birds occasionally, and are apparently useful for controlling feral pigeons in this way³.On garden feeders they can be surprisingly acrobatic.

An acrobatic jackdaw on our fat ball feeder last winter

Jackdaw life revolves around the social scene. They live in flocks, foraging, flying, roosting and nesting together in groups which are often entertaining to watch. Esther Woolfston, admirer of corvids describes how they “dive with their black and sinuous flight, swoop, loop and spiral” through castle ruins⁴ . Within these groups there is a complex social hierarchy, and these interactions were studied very early on, in the 1930’s by Konrad Lorenz. He found that whilst bachelors are dominant over spinsters, females gain equal status as their mates once they pair up.  Individuals use this strict hierarchy, coupled with a varied body language to avoid physical fighting and dominant males often act as peacekeepers⁵.  If a fight does break out, the whole colony gets excited and surrounds them like children at a playground tussle⁶.

The advantage of group living for jackdaws is beyond simple safety in numbers. Group members actively look out for each other. If one is grabbed by a predator, the rest will bear down on the enemy, cawing angrily⁶. Even the passing resemblance of a fluttering black plastic bag to a struggling jackdaw can provoke them⁷. One of their main predators are female Sparrowhawks (Accipiter nisus), which can just about restrain one jackdaw let alone an angry flock.

 Like other corvids, jackdaws mate for life and pairs always stick together, even within the larger flock. They share nesting duties equally, and feed and preen one another. Remarkably, unlike many other ‘monogamous’ birds, Jackdaws don’t cheat on their partners, even though they have plenty of flock mates to choose from⁸ (Male rooks Corvus frugilegus, by contrast, regularly take advantage of neighbouring nesting females)⁹. Young jackdaws even generously offer food to their peers, which helps them make friends¹⁰.

Jackdaws may even be social towards other species. They often roost together with rooks, and the resulting evening flocks are a spectacle of sight and sound. Underlying these are strict rules governing the position of the species and individuals¹¹. Fascinatingly, I met a birdwatcher  who claimed he had seen inter-species play of ‘catch the stick’ between rooks and jackdaws^ᵻ.

The only time Jackdaws show real hostility is when nesting. They nest in holes, a naturally scarce resource, so there is intense competition between pairs. This year’s ‘Springwatch’ focused on a Jackdaw nest that another pair were determinedly trying to oust by harassing the chicks and stealing nesting material. They commonly nest in boxes meant for owls or kestrels (Falco tinnunculus , and will doggedly defend their spot against them.  Most famously, they will use chimney pots, dropping down sticks until they form a platform, one pile measured 2.4m across and 1m high¹. See one here.

Astounding footage of a Jackdaw tenaciuosly defending a next box against a Kestrel that wants it for itself.

With a complex social life and pugnacious attitude, the Jackdaw is definitely deserving of higher esteem than its name suggests. It has been a fascinating bird to research.

*The genus also includes the raven C.corax, Carrion crow C.corone, Hooded crow C.cornix and the Rook C.frugilegus in the UK.

^ᵻ This is not implausible, there are lots of observations of corvids playing.

References

1-BTO (2012). The Crow next ‘daw’: Jackdaw. BirdTable. Available from: http://www.bto.org/sites/default/files/shared_documents/gbw/associated_files/bird-table-70-jackdaw-article.pdf

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

3- Percy Trett. (No date) Jackdaw. Birds of Britain. Available from:  http://www.birdsofbritain.co.uk/bird-guide/jackdaw.asp

4- Esther Woolfston. (2008) Corvus: A Life with Birds. Granta Publications.

5- Konrad Lorenz . (1931) Beiträge zur ethologie sozialer Corvidae. Journal of Ornithology  80, 50-98. Cited by: A. Röell. (1978) Social Behaviour of the Jackdaw, Corvus monedula, in Relation to Its Niche. Behaviour,  64 (1/2), 1-124. Available from: http://www.jstor.org/stable/4533862

6-A. Röell. (1978) Social Behaviour of the Jackdaw, Corvus monedula, in Relation to Its Niche. Behaviour,  64 (1/2), 1-124. Available from: http://www.jstor.org/stable/4533862
      - (A thorough Paper on Jackdaws and their social behaviour)

7- Konrad Lorenz. (1952). King Solomon’s Ring: New Light on Animal Ways. (Translated from the German by Marjorie Kerr Wilson). Clay and Company, Suffolk.

8- Auguste M. P. von Bayern, Selvino R. de Kort, Nicola S. Clayton and Nathan J. Emery. (2007) 733The role of food- and object-sharing in the development of social bonds in juvenile jackdaws (Corvus monedula). Behaviour, 144 (6), 711- 733. Available from: http://www.jstor.org/stable/4536473

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

10- I. G. Henderson, P. J. B. Hart, and T. Burke. (2000). Strict monogamy in a semi-colonial passerine: the Jackdaw Corvus monedula. Journal of Avian Biology, 31 (2), 177–182.
Mentioned by:  Dominic Couzens. (2012) Garden Birds Confidential. Bounty Books.


11- University of Exeter. (2013). How birds of different feathers flock together. Available from: http://www.exeter.ac.uk/news/research/title_271250_en.html