W is for Woodpigeon

WOODPIGEON (COLUMBA PALUMBUS)

There is no such thing as ‘just a pigeon’. It amazes me that people don’t realise the difference between the feral, city pigeon (domesticated descendants of rock doves* Columba livia originally kept for food), and the fully wild wood pigeon Columba palumbus.  ‘Woodies’ can be discerned by their salmon-pink breast  and white neck clasp, and wing patches. Like feral pigeons, they have an iridescent flash on their their neck, glinting metallic green and purple. The rest of their body is a pastel blue- grey.

Woodpigeons are also larger than feral pigeons (around 50% heavier¹), one of our biggest garden birds. They’re often thought of as fat and can look quite comical strutting with their tiny legs. One of my friends likens them to the portly figure of Winston Churchill. In truth though, their breast is mainly powerful flight muscle, not flab. 

But they are certainly big eaters. Wood pigeons are mainly herbivorous, grazing on plants and shoots and gulping down seeds, berries, buds and leaves along with the occasional insect, worm or snail^2,3.  A wide gape allows them to swallow acorns whole and despite their size, they are capable of quite acrobatic feats to feed on fruiting branches.
Plant foods are difficult to digest, so they eat a lot. This makes them a serious pest as winter flocks descend in their hundreds on fields of cereals and vegetables, and are understandably shot to control their numbers. One woodpigeon was found with its crop and stomach full of 1020 grains of corn, whilst another had swallowed 198 beans⁴.  They’re also begrudged in gardens for `taking food meant for smaller birds. This can be averted by caging the feed or using smaller seed mixes⁵. I personally welcome woodies in the garden over the more piggish feral pigeons.

The woodpigeon was proclaimed Britain’s commonest garden bird in 2005⁶. Once limited to rural woods and fields, their numbers have soared due to changing practices on the farms they pilfer. Switching from spring to autumn sowing of cereals and increased growing of oilseed rape provide extensive winter food sources which help the pigeons survive the leaner times. It is from these farms that many have spilled into suburban and urban areas⁵. They even outnumber their feral cousins in London gardens⁷.

But winter survival is only half the story. Woodpigeons can also breed all year round provided there is enough food available, thanks to a trick up their sleeve, or rather down their throat.

Most birds feed their young on insects to provide the protein they need to grow, restricting their breeding season to the warmer spring and summer months. Pigeons have curbed this by producing a protein-rich milk. Yes, milk!  Of course this ‘pigeon milk’ does not come from teats but from a cell lining of the crop. More winter food means woodpigeons can raise more broods later.

Woodpigeons mate for life, and courting males go to great effort to earn their mates. Their haughty cooing has a drowsy quality that accentuates the humid late summer. They also perform display flights, flapping vertically into the air before gliding down in a wide arc. Any interested female is greeted with a display of tilting,tail-fanning and cooing . Though she will often spurn his advances, he follows her persistently. If they suit, they become hopeless romantics, cuddling up together, preening and even ‘kissing’ by locking beaks and exchanging food. 

Woodpigeon courting (Video by vriesap) and song (Recording by Ashley Fisher). 

The couple builds a messy platform of sticks in the branches of a tree. Their plain white eggs can sometimes be seen from below. The young pigeons, called squabs have faces only a mother could love with bulging eyes, a roman nose and straggly down, growing into juveniles which lack the white markings of the adults.

Male woodpigeons are defensive of their breeding territories and mates, getting into fights by smacking each other with their wings. These tussles look silly, but the blows are powerful. Woodpigeons also clap their wings together over their backs when fleeing a predator, sounding a clattering alarm signal. Buzzards Buteo buteo, female sparrowhawks  Accipiter nisus, foxes Vulpes vulpes and humans all enjoy a meaty woodpigeon.

All too often we hear of species declining due to human land use. The woodpigeon provides a brilliant example of the opposite, even if it is at our expense. Whether viewed as a pest or handsome garden visitor, even the humble woodpigeon has a remarkable life. It is far from “just a pigeon”.

* There's no real difference between 'pigeons' and 'doves'. The sacred white dove symbol of christianity is simply a colour form of domestic pigeon. 

References

1- R.A. Robinson. (2005) BTO BirdFacts: profiles of birds occurring in Britain & Ireland: Woodpigeon Columba palumbus   [Linnaeus, 1758]. (BTO Research Report 407). BTO, Thetford. Available from:  http://blx1.bto.org/birdfacts/results/bob6700.htm

2- Peter Holden and Tim Cleeves. (2010) RSPB Handbook of British Birds (Third Edition). London, A&C Black.

3- Peter Holden and J.T.R. Sharrock. (1988) The RSPB Book of British Birds. London, Papermac.

4- Mark Cocker and Richard Mabey. (2005) Birds Britannica. London, Chatto and Windus.

5- BTO (No date) A BTO Garden BirdWatch factsheet: Woodpigeon. Available from: http://www.bto.org/sites/default/files/u23/downloads/pdfs/factsheet_woodp.pdf

6- BBC News. (2004) Wood pigeon 'most common UK bird'. Available from: http://news.bbc.co.uk/1/hi/uk/4646685.stm

7- BBC News. (2008) Wood pigeons 'flocking to towns'. Available from: http://news.bbc.co.uk/1/hi/7166536.stm

N is for Nuthatch

NUTHATCH (SITTA EUROPAEA)

With its powder blue upperside, blended cream and rusty orange underside and charcoal bandit mask , the Nuthatch Sitta europaea looks as if it has been coloured with pastilles, but is surprisingly difficult to see in its shady habitat. The nuthatch is truly a woodland bird, and with good reason. Like a woodpecker (which it resembles) it finds food on and under tree bark, hopping up, down and around the trunk and branches in search of insects. The nuthatch is the only British bird capable of climbing down a tree trunk head first. They achieve this through not relying on their tail as a prop, as woodpeckers and treecreepers Certhia familiaris do, and by having especially large, strong feet which they position one behind the other to act as a pivot and support¹.

The nuthatch reveals itself by its insistent piping call or the crackling sound of it pecking and peeling bark. Even then, they are difficult to keep track of as they scoot and weave behind the tree in and out of view.  However, they are quite tame and will call or feed a couple of meters away.

The nuthatch also eats seeds and nuts in autumn and winter when insects become scarce, cracking them by shoving them into a bark crevice and thrusting down with its powerful beak. This habit earned them their original, more powerful name ‘Nut hacker’ which has since become corrupted².

Nuthatches are partial to peanuts and seeds from garden feeders and bird tables, where they aggressively chase off other small birds, especially other nuthatches. Though they are increasingly seen in gardens where they are most easily observed, they only visit those near woodlands. Nuthatches stay very close to their birthplace, and even patches of suitable natural woodland may not be colonised if they are too far from others³. However, nuthatches are slowly moving North with warmer British weather, and were first recorded breeding in Scotland in 1989⁴

Perhaps because they don’t move far and because they nest in scarce tree holes, territory is very important to nuthatches. Neighbouring pairs have frequent stand-offs. Usually these are just posturing, but sometimes they escalate into fights when their beaks often inflict serious injury or death⁴.  Juvenile nuthatches have to wait in the wings in low-quality territories until a position in a breeding territory becomes available⁵. Though they are a small bird and reach adulthood at just 1 year, nuthatches have been recorded at 7 years old⁶.

Nuthatches are crafty birds. They store seeds and nuts for the winter by pushing them into gaps in tree bark or wood. Come nesting time, they will plug up their nest hole with mud, which hardens like concrete until only their bodies can pass through. This keeps out nest predators such as woodpeckers and competitors like starlings Sturnus vulgaris, but they can be over-enthusiatic, filling up the joins in nestboxes and even encasing them entirely ^1,3!
 I have also once seen one of a pair of nuthatches in Worcester use a piece of bark to prise off another part and wondered if this counted as tool use. This behaviour (this time with a small stick) has been photographed before.  Its American relative, the brown-headed nuthatch is renowned for using tools in a similar way.

Next time you’re in a woodland, make an effort to listen out for this agile and crafty character around a tree trunk near you.

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- Peter Holden and J.T.R. Sharrock. (1989) The RSPB book of British Birds. PAPERMAC, London.

4-Tim Harrison and Mike Toms. (2012) BTO Garden Bird of the Month – November: Nuthatch. Available from: http://www.discoverwildlife.com/blog/bto-garden-bird-month-%E2%80%93-november-nuthatch

5- Erik Matthysen.(1990) Behavioural and ecological correlates of territory quality in the Eurasian Nuthatch (Sitta europaea). The Auk, 107 (1), 86-95. Available from: http://www.jstor.org/discover/10.2307/4087805?uid=3738032&uid=2129&uid=2&uid=70&uid=4&sid=21102756365933

6- R.A. Robinson.(2005) BTO BirdFacts: profiles of birds occurring in Britain & Ireland: Nuthatch Sitta europaea Available from: http://blx1.bto.org/birdfacts/results/bob14790.htm