Mystery of the vanishing sparrow

The Independent offered £5,000 for a convincing theory about why the house sparrow was dying out in cities. The answer seems to lie with falling insect numbers, reports Michael McCarthy


It's taken eight-and-a-half years – but
The Independent's £5,000 prize for explaining the disappearance of the house sparrow from our towns and cities finally has a serious entry, with a serious theory.

Insect decline, featured prominently in this newspaper last Saturday, is offered as the reason for the biggest bird mystery of modern times by a group of four scientists from the Royal Society for the Protection of Birds (RSPB), De Montfort University in Leicester and Natural England, the Government's wildlife agency.

Their theory, put forward in a scientific paper to be published in a forthcoming issue of the journal Animal Conservation, is based on intensive research in Leicester, showing that sparrow chicks were starving in their nests because their parents could not find enough insects to feed them. So many chicks were dying that the birds' population level as a whole was declining.

The paper has been entered for The Independent's prize, which was reported around the world when it was announced on 16 May 2000, as the start of a campaign to Save The Sparrow.

One of the authors, Dr Kate Vincent, who carried out the research on which the theory is based, said: "If we were successful, given the statuses of the collaborating organisations, we feel that any prize money received should be spent on further research or conservation work on house sparrows. From The Independent's point of view it would be a natural progression to know that your Save The Sparrow campaign prize money would be engineering further sparrow research, which we feel would be something to celebrate."

The £5,000 prize was offered for a peer-reviewed paper published in a scientific journal, which – in the opinion of our referees – would account for the disappearance of the house sparrow, Passer domesticus, from towns and cities in Britain. The referees are the RSPB, the British Trust for Ornithology (BTO), and Dr Denis Summers-Smith, an internationally renowned expert on sparrows. (It was stated at the time that researchers from the RSPB and BTO would not be precluded from entering.) The referees will now be considering the paper to see if it does indeed account for a remarkable wildlife enigma.

House sparrows in Britain have declined by 68 per cent since 1977, but the decline has been overwhelmingly an urban one. Although still relatively plentiful in small towns in the countryside and by the sea, in many major conurbations, sparrows have disappeared. Numbers started falling in cities in the mid-1980s and the species has virtually vanished from central London – for example, St James's Park holds all the common garden birds such as blue tits, robins and blackbirds, but sparrows, which were once plentiful, died out in the park in the late 1990s. There was no obvious cause. House sparrows are also disappearing from Bristol, Edinburgh and Dublin, as well as Hamburg, Prague and Moscow but curiously, they are faring better in Paris and Berlin.

When The Independent launched its campaign, many potential reasons for the decline were suggested by readers, which included increased predation by cats, magpies and sparrowhawks (all of which have increased in our cities); disease contracted from bird food such as peanuts; increased use of pesticides; collective suicide; radiation from the Chernobyl nuclear accident in the former USSR; the disappearance of sparrow nesting places as houses were modernised and gardens were tidied up or concreted over as car ports, and a decline in insects. (Although adult sparrows are seed-eating birds, the young need insect food in the first few days of their lives).

The last two potential causes – lack of nesting places and insect shortage – have always seemed the most likely (although many people blame magpies and other predators for declines in small birds, both the RSPB and the BTO say this is not borne out by the figures).

A leading proponent of the insect shortage theory was Dr Summers-Smith, a retired engineer from Guisborough in Cleveland, and the author of the standard monograph on the house sparrow, and several other sparrow books. He felt that chick starvation might well be the cause of the fall in numbers as a whole, although he was unable to prove it.

This appears to have been borne out in the new paper. The lead author, Dr Will Peach from the RSPB, said: "Each pair of house sparrows must rear at least five chicks every year to stop their numbers falling.

"But in our study, too many chicks were starving in their nests. Others were fledging [leaving the nest] but were too weak to live for much longer than that. If the birds nested in areas rich in insects, they did much better.

"Where there were few insects, young house sparrows were likely to die. Young house sparrows need insects rather than seeds, peanuts or bread to survive."

Dr Vincent, then of De Montfort University in Leicester, said: "This is one of the most mysterious and complex declines of a species in recent years. The study highlights that sparrow chicks are hatching but they aren't surviving.

"This is partly down to the loss of green spaces within British cities through development on green space, tree removal and the conversion of front gardens for parking. The loss of deciduous greenery within urban areas may have made life much more difficult for birds like house sparrows that need large numbers of insects to feed their young."

Phil Grice, senior ornithologist at Natural England, said: "This study highlights the importance of using native varieties of plants in our urban green spaces which, in turn, support large numbers of insects that are important in the diet of house sparrows and a range of other birds that we love to see in our gardens".

The paper, Reproductive success of house sparrows along an urban gradient, by W J Peach, K E Vincent, J A Fowler and P V Grice, is now being sent to our referees and we shall report soon on their verdict.

Suggested Topics
Have you tried new the Independent Digital Edition apps?
Life and Style
Google celebrates the 126th anniversary of the Eiffel Tower opening its doors to the public for the first time
techGoogle celebrates Paris's iconic landmark, which opened to the public 126 years ago today
Cleopatra the tortoise suffers from a painful disease that causes her shell to disintegrate; her new prosthetic one has been custom-made for her using 3D printing technology
newsCleopatra had been suffering from 'pyramiding'
Life and Style
Baroness Lane-Fox warned that large companies such as have become so powerful that governments and regulators are left behind
techTech giants have left governments and regulators behind
Arts and Entertainment
Coachella and Lollapalooza festivals have both listed the selfie stick devices as “prohibited items”
Nigel Owens was targeted on Twitter because of his sexuality during the Six Nations finale between England and France earlier this month
rugbyReferee Nigel Owens on coming out, and homophobic Twitter abuse
Arts and Entertainment
Tracey Emin visits her 1990s work ‘My Bed’ at Tate Britain in London, where it is back on display from today
artsBut how does the iconic work stand up, 16 years on?
  • Get to the point
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
iJobs Job Widget
iJobs General

Recruitment Genius: Senior Web Designer / Front End Developer

£28000 - £32000 per annum: Recruitment Genius: This fast expanding web managem...

Ashdown Group: Trainee Consultant - Surrey / South West London

£22000 per annum + pension,bonus,career progression: Ashdown Group: An establi...

Ashdown Group: Trainee Consultant - Surrey/ South West London

£22000 per annum + pension,bonus,career progression: Ashdown Group: An establi...

Ashdown Group: Recruitment Consultant / Account Manager - Surrey / SW London

£40000 per annum + realistic targets: Ashdown Group: A thriving recruitment co...

Day In a Page

No postcode? No vote

Floating voters

How living on a houseboat meant I didn't officially 'exist'
Louis Theroux's affable Englishman routine begins to wear thin

By Reason of Insanity

Louis Theroux's affable Englishman routine begins to wear thin
Power dressing is back – but no shoulderpads!

Power dressing is back

But banish all thoughts of Eighties shoulderpads
Spanish stone-age cave paintings 'under threat' after being re-opened to the public

Spanish stone-age cave paintings in Altamira 'under threat'

Caves were re-opened to the public
'I was the bookies’ favourite to be first to leave the Cabinet'

Vince Cable interview

'I was the bookies’ favourite to be first to leave the Cabinet'
Election 2015: How many of the Government's coalition agreement promises have been kept?

Promises, promises

But how many coalition agreement pledges have been kept?
The Gaza fisherman who built his own reef - and was shot dead there by an Israeli gunboat

The death of a Gaza fisherman

He built his own reef, and was fatally shot there by an Israeli gunboat
Saudi Arabia's airstrikes in Yemen are fuelling the Gulf's fire

Saudi airstrikes are fuelling the Gulf's fire

Arab intervention in Yemen risks entrenching Sunni-Shia divide and handing a victory to Isis, says Patrick Cockburn
Zayn Malik's departure from One Direction shows the perils of fame in the age of social media

The only direction Zayn could go

We wince at the anguish of One Direction's fans, but Malik's departure shows the perils of fame in the age of social media
Young Magician of the Year 2015: Meet the schoolgirl from Newcastle who has her heart set on being the competition's first female winner

Spells like teen spirit

A 16-year-old from Newcastle has set her heart on being the first female to win Young Magician of the Year. Jonathan Owen meets her
Jonathan Anderson: If fashion is a cycle, this young man knows just how to ride it

If fashion is a cycle, this young man knows just how to ride it

British designer Jonathan Anderson is putting his stamp on venerable house Loewe
Number plates scheme could provide a licence to offend in the land of the free

Licence to offend in the land of the free

Cash-strapped states have hit on a way of making money out of drivers that may be in collision with the First Amendment, says Rupert Cornwell
From farm to fork: Meet the Cornish fishermen, vegetable-growers and butchers causing a stir in London's top restaurants

From farm to fork in Cornwall

One man is bringing together Cornwall's most accomplished growers, fishermen and butchers with London's best chefs to put the finest, freshest produce on the plates of some of the country’s best restaurants
Robert Parker interview: The world's top wine critic on tasting 10,000 bottles a year, absurd drinking notes and New World wannabes

Robert Parker interview

The world's top wine critic on tasting 10,000 bottles a year, absurd drinking notes and New World wannabes
Don't believe the stereotype - or should you?

Don't believe the stereotype - or should you?

We exaggerate regional traits and turn them into jokes - and those on the receiving end are in on it too, says DJ Taylor