S is for Sparrowhawk

SPARROWHAWK (ACCIPITER NISUS)

To some, a swift demon snatching defenceless birds from their garden feeders.  To others, an exciting reminder of the wild on their doorstep. The sparrowhawk Accipiter nisus embodies the attitude of nature red in (beak) and claw.

Sparrowhawks usually make a surprise appearance, often a fleeting glimpse as one shoots by. In flight, the sparrowhawk has a distinctive outline with short, broad wings and a long oblong tail. When resting, their glaring yellow eyes are another striking feature. Sparrowhawks are usually silent, but are often heralded by the alarm calls of other birds.

Female sparrowhawks are 25% bigger than males, a record breaker amongst birds¹. This helps avoid competition for prey. Males hunt small birds like tits, finches and sparrows whilst the females take thrushes, corvids and pigeons.
Their colouring is also different. The male casts a handsome figure with a slatey blue back and fine orange bands across his chest whilst the female has a browner back and chest bands.

Sparrowhawks are woodland birds by nature, but the planted trees and bird communities of gardens are a good substitute. Over 90% of their prey is live birds, with small mammals (including bats), carrion and insect snacks occasionally on the menu². In general, sparrowhawks aren't fussy, taking whichever bird is readily available. In his 30 year observations, J.H.Owen noted 57 prey species².

 The sparrowhawks’ hunting strategy is to coast around behind cover³ (Trees, hedgerows, fences and even people on the streets*) before bursting into a surprised group of birds and snatching its prey with long, lobed talons perfect for gripping a moving target. If given the slip, the sparrowhawk’s specialised wings and tail come into action steering over, under and between branches at speeds of up to 50kph⁴. The hawk despatches its prey with talon squeezes or eats it alive depending on which is easier. Sparrowhawks are even known to drown prey^ᵻ. The forensic signs of a sparrowhawk kill are scattered, plucked feathers and missing head and/or breast meat, the raptor’s choice delicacies.  

Watch how the sparrowhawk manouvres between branches in this clip from the legendary David Attenborough's 'Life of Birds' series.


The sparrowhawks hunting skill has shaped its scientific name (Accipiter from accipere, to grasp¹) and has been honoured in human weaponry. The musket (an early hand gun) was named after the falconer’s term for the male sparrowhawk- both being small, fast and deadly⁵.

Sparrowhawks are such infamous predators of other birds that they have been scapegoated for causing songbird declines. The sparrowhawk’s recovery from persecution by gamekeepers and poisoning by DDT (a pesticide that builds up through the food chain) since the 1960’s coincided with the decline in small woodland and farmland birds⁶. It is easy to put two and two together and some organisations such as the “Songbird Survival” did (and partly still do) just that⁷.

But the evidence does not support this. Studies show that songbirds are thriving where sparrowhawk populations are highest⁸, and sparrowhawks act as ‘compensatory predators’⁹, meaning they only kill prey in numbers which would have died from natural causes anyway, such as harsh winters. This makes obvious sense since the predator relies on good prey populations, and depleting their food source would doom the sparrowhawks in the long run. In other words, most small birds survive to breed in the same numbers whether or not sparrowhawks are around, and human-caused habitat loss and land management changes are far greater causes of songbird decline^7,9.  Even around garden feeders which often become sparrowhawk magnets, birds adjust their behaviour to cope- feeding little and often to avoid becoming full and sluggish targets⁹.

Sparrowhawks themselves are not invincible. They must watch their own backs for larger peregrines Falco peregrinus and goshawks Accipiter gentilis and harsh winters that kill off small birds lead sparrowhawks to starve in turn¹⁰. Sparrowhawks are short lived for a raptor, and less than half their breeding attempts produce fledglings¹⁰. Like most predators, they simply cannot reach damaging numbers.

It is time we stopped viewing sparrowhawks as detached murderers of our garden treasures and recognise them as yet another beautifully adapted predator inextricably linked with the fate of our smaller birds. It is a testament to changing times that the sparrowhawk has managed to become so common around our homes.

*One of my most memorable encounters with a sparrowhawk was when one flew past chasing a sparrow just inches from my face as a child!

^ᵻThis may seem barbaric and upsetting to our eyes, but as with all predators, the sparrowhawk acts on efficiency, not moral code. Is a song thrush bashing a live snail on a rock any less ‘barbaric’?

  References

1- R.A. Robinson. (2005) BTO BirdFacts: profiles of birds occurring in Britain & Ireland:Sparrowhawk Accipiter nisus. Available from: http://blx1.bto.org/birdfacts/results/bob2690.htm

2-J.H. Owen. (1932) The Food of the Sparrow-Hawk. British Birds,26, 34 – 40. Available from: http://www.britishbirds.co.uk/search?model=pdf&id=1444

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

4- RSPB. (2013) Birds by name: Sparrowhawk: Hunting. Available from:  http://www.rspb.org.uk/wildlife/birdguide/name/s/sparrowhawk/hunting.aspx

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

6- BTO. (2013) Bird of the Month: Sparrowhawk. Available from: http://www.bto.org/about-birds/bird-of-month/sparrowhawk

7- Songbird Survival. (2013) Save our Songbirds. Available from: http://www.songbird-survival.org.uk/save_our_songbirds.html

8- RSPB. (2013) Birds by name: Sparrowhawk: A top predator. Available from:  http://www.rspb.org.uk/wildlife/birdguide/name/s/sparrowhawk/toppredator.aspx

9- Mike Toms. (2008) Return of the Native. Birdtable, 56,7-11. BTO. Available from: http://www.bto.org/sites/default/files/shared_documents/gbw/associated_files/bird-table-56-2008-sparrowhawk-article.pdf

10-RSPB. (2013) Birds by name: Sparrowhawk: Mortality. Available from:  http://www.rspb.org.uk/wildlife/birdguide/name/s/sparrowhawk/mortality.aspx

R is for Redwing

REDWING (TURDUS ILIACUS) 

From a summer migrant (Q is for Quail) we move to a more topical winter migrant, the Redwing Turdus iliacus. The smallest of our ‘true thrushes’ (from the genus Turdus), the redwing arrives to Britain in droves from the forests of Northern Europe, seeking out our richer winter larder.

Walking home on a crisp autumn night, you may be surprised to hear a soft “tseep” from the skies above. This is the sound of redwing migrating under cover of darkness. During the day it is easy to identify flocks of redwing by their size (A little larger than a robin) and their plumage patterns. They are darker than a song thrush Turdus philomelos , with a mahogany upperside, pale eyebrows, white, speckled chest and of course red underwings and flanks. Another flocking winter migrant thrush is the Fieldfare Turdus pilaris which is much larger with different plumage (The difference is explained in this video by the BTO).

Redwings are renowned berry-guzzlers. Scattered along a hedgerow or fruiting tree, they gulp down berries of hawthorn, rowan, and holly, sometimes creating quite a festive scene amongst the frosted, berry-laden branches. The arrival of redwings is much to the chagrin of Mistle Thrushes Turdus viscivorous, which stake out their own berried bush for the winter and fruitlessly attempt to guard it against the onslaught of their smaller cousins.  Redwings sometimes visit gardens in harsher weather where there are pickings of ornamental berry bushes such as cotoneaster and pyracanthus or handouts of fruit like apples. The orchards of the West Midlands are an important feeding area for redwings to stock up on windfall apples¹.

But redwings won’t pass up the opportunity for something meatier and can often be seen hopping across playing fields and farmland in search of worms. They will also split up and rummage through woodland leaf-litter for insects, especially when it is too cold and windy to be out in the open². Redwings are well camouflaged against the woodland carpet, and their reaction to predators is often to sit still and make like a leaf³. When startled in the open, redwings head for cover in trees or bushes.

There are actually two races of redwing that visit Britain. The slightly paler  Scandinavian race T. iliacus iliacus, winter in Southern Britain, whereas the darker, streakier Icelandic race T.iliacus corburni  winter around Scotland and Ireland ^2,4. Of course there is some overlap , especially since redwings are not site-faithful at all during the winter and will move around depending on the weather and food availability, going south in harsher conditions ^1,3. Scandinavian birds sometimes fly all the way down to North Africa².

Some Icelandic birds don’t even bother going home, and actually breed in Northern Scotland ^1,4. This was first noticed in 1932 and numbers grew to around 80 pairs in the early 80’s, but have since fallen to less than 20 ^1,4. This small breeding population is why redwings have a red RSPB conservation status in the UK². It may be novel, but the over 1000 strong winter migrant population⁴ is perhaps a more important concern.

Wintering birds have also shown signs of decline, with lessreports of spectacular communal roosts². Perhaps this is because there are less fruiting hedges in our countryside. Even those that still exist are often cut too often by flailing to allow berry production.

As the colder seasons set in, look out for this winter special, that is perhaps more festive than our resident robin. Lay out a few apples in your garden as a helping hand to our winter thrushes and you may be lucky enough to be visited by a party of handsome redwing.

References

1- Graham Appleton. (2012) Bird of the Month: Redwing. BTO. Available from: http://www.bto.org/about-birds/bird-of-month/redwing

2- Mike Toms. (2010) The Wanderer Returns: REDWING. Bird Table, 64, 14-16. Available from: http://www.bto.org/sites/default/files/shared_documents/gbw/associated_files/bird-table-64-redwing-article.pdf

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

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

Q is for Quail

QUAIL (COTURNIX COTURNIX)

At just 17 centimetres long, the quail (Coturnix coturnix)is our smallest and sweetest gamebird. It is also one of the most rarely seen.

The quail’s streaky buff, tan and chocolate markings provide excellent cryptic camouflage in the grassland habitats they favour. Their low stature and secretive habits help keep their cover. Males can be located by their distinctive “whip whip whip” call, often described as ‘wet my lips’ which they will shout out day and night. If you do see one, males are subtly different from females, with bolder, darker chin markings, whilst juveniles are plain-faced.

Despite being a weak flier, quails are our only migratory gamebird, arriving here to breed in spring and summer (April to September) from the warmer climes of North and Central Africa. In keeping with their secrecy, they fly under cover of darkness to avoid hawks and other birds of prey.

Unlike the swallow Hirundo rustica or the cuckoo Cuculus canorus though, quails are not reliable visitors to Britain. They reach our islands sporadically, in varying numbers each year.  They are never particularly common in Britain, with the usual number of just 100-300 pairs reaching up to around 2,600 in good ‘Quail years”¹.  Notable quail years have included  1970, 1983, 1989 and 2005¹. Quails are classed as a ‘rare breeding bird’ by the BTO, so any records are notable².

However, quail migration does follow an interesting pattern. The first wave of migrants arrive in April to May, breeding through to June and July, when the second wave arrives. The reason for this is simple, yet remarkable. The second wave are the first brood of youngsters from North Africa (Sired by parents from Central Africa). Meanwhile, young quails hatched in Britain migrate into Northern Europe².  This feat is possible because of the quail’s fast growth rate; juveniles have the strength to migrate at 2 months old and can breed at just 3 months ^2,3! This leapfrogging migration pattern is has more in common with butterflies, such as the painted lady Vanessa cardui than other birds.

You might think with such a high breeding rate, quails would be very numerous. In fact
Whilst captive quails have grown in popularity for their eggs, meat and as pets, their wild cousins are steadily declining. A number of factors are to blame for this, from habitat loss due to changes in farming practices and losses of semi-natural grassland, to droughts in their African wintering grounds and hunting in the Mediterranean³.

Of these, hunting is the most pressing conservation concern. Quails are strictly protected under the European Union’s Birds Directive, but illegal spring shooting and trapping continues on their migration through the Mediterranean, which selectively removes hundreds of breeding birds^4,5. Malta in particular is criticised for this practice, banned by the Government in 2009 but reopened in 2011 with annually increasing quail quotas⁵. Outside of Europe, such as in the Middle-East, quail shooting is also a popular sport and a tourism venture. Considering the small numbers arriving in Britain each year, this is a clear conservation issue and the fact that all but one of the BTO’s notable quail ringing recoveries were from shot birds is not surprising⁶.

Surprisingly then, the quail was a historically unpopular gamebird, rarely eaten at British banquets which featured so many other species⁷. The reason is not their small size but their toxicity.  The flesh of some quails is made bitter and poisonous by their habit of eating toxic plants-such as spurge- on migration^7,8. Apparently, only birds from East Africa are affected, but since the populations mix in the breeding grounds, it wasn’t considered worth the lottery. Quail poisoning , or “coturnism” was so common it has been mentioned in the Bible (Numbers 11:31-34) when the Israelites ate quail in Sinai, and eating quail was banned by the Romans in the first century. This makes the quail one of only five known poisonous birds⁸.

They may be small, but the quail’s secretive lifestyle hides some big secrets.  It’s clear that this unique gamebird deserves more protection if we want to hear them in our island’s summer fields in future years.



References

1-Chris Mead. (2000) Quail (Common Quail). The State of the Nations Birds. Available from: http://www.birdcare.com/bin/showsonb?quail

2-Dawn Balmer . (2009) Quail - the Painted Lady of the bird world? Available from: http://www.birdguides.com/webzine/article.asp?a=1690

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

4- Committee Against Bird Slaughter (CABS). (2010) Spring Hunting on Malta: Hunters have no sense  of 'sustainability'.  Available from: http://www.komitee.de/en/actions-and-projects/malta/spring-hunting

5-Charlie Moors. (2012) BirdLife Malta: ““Malta Taking Commission for a Ride”. Talking Naturally. Available from: http://www.talking-naturally.co.uk/birdlife-malta-malta-taking-commission-for-a-ride/

6- R.A. Robinson and J.A. Clark. (2013) The Online Ringing Report: Bird ringing in Britain & Ireland in 2012. Summary of all Ringing Recoveries for Quail (Coturnix coturnix). Available from: http://blx1.bto.org/ring/countyrec/resultsall/rec3700all.htm

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

8-Dr Stefan Bartram and Professor Wilhelm Boland. (2001) Chemistry and ecology of toxic birds. ChemBioChem, 2, 809-811. In: Darren Naish. (2010) Death by toxic goose. Amazing waterfowl facts part II. Tetrapod Zoology. Available from: http://scienceblogs.com/tetrapodzoology/2010/06/19/death-by-toxic-goose/