Food chain in disarray after changes in voles' boom-and-bust breeding cycle

 

A A A

A small, brown rodent that is a staple source of food for a range of iconic species – from the barn owl to the Arctic fox – has undergone a dramatic and perplexing change in the way it breeds, scientist have found.

Normally, voles reproduced rapidly and over a three or four-year cycle they go through dramatic population booms, inevitably followed by a bust, which determines how many predators can live in a particular area.

However, scientists have discovered that throughout Europe, vole populations are no longer showing the dramatic boom-and-bust cycles that have characterised the species on which many other animals depend for survival.

A study of 12 vole populations from Scandinavia to southern France has found that over the past 30 or 40 years the natural dramatic spikes of the vole population have become much smaller for unknown reasons.

Instead of seeing up to 500 voles living in an area the size of a football pitch, scientists are recording a maximum of about 50, which falls down to just two or three when there is a natural drop in numbers as the cycle goes through a bust period, said Xavier Lambin, professor of ecology at Aberdeen University.

“Smaller herbivores like voles have population cycles which have a boom or bust dynamic – there used to be times of plenty of the animals and times of scarcity, as part of natural processes,” Professor Lambin said.

“However evidence has emerged in recent years of a greater uniformity in vole abundance between years. The outbreaks are no longer as marked. Like a weakening heart, the beat of the cycle is becoming fainter and this will profoundly affect many other species,” he said.

The fact that the same trend has occurred over a wide area of Europe and that it has occurred during the same period suggests a continent-wide cause. The scientists believe that climate may be playing a role as vole numbers during the winter months appear to have collapsed.

“We studied 12 populations of voles across Europe and found that while a faint population cycle remains, it’s now much dampened down. The change is most evident in spring, reflecting a worsening of conditions for voles over winter,” Professor Lambin said.

The study, published in the journal Nature, relied on detailed records of vole numbers going back to the 1970s from sites as varied as Kielder Forest in Northumberland, Rochefort in France and Umea in Sweden. The vast majority of the vole populations showed a dramatic decline in the boom-bust cycle, although two sites in Poland and the former East Germamy appeared to retain the original cycle.

“This change in one group of species at the bottom of the food chain is bad news for a diverse range of predators which relied on these years of plenty,” Professor Lambin said.

Voles, which live off plants, are at the base of the food chain and are considered a “keystone” species in ecology. The Arctic fox and barn owl depend on it heavily, as does the kestral and weasel, Professor Lambin said.

“The world will be a less exciting place without those spectacular fluctuations.  It is a bit as if the Serengeti was to lose the huge disturbance caused by the large herds of wildebeest, zebra and antelopes migrating. Here such a change is taking place on our door step, in Europe,” he said.

Arts and Entertainment
The Doctor and Clara have their first real heart to heart since he regenerated in 'Deep Breath'
TV
Arts and Entertainment
James Hewitt has firmly denied being Harry’s father
arts + ents
Arts and Entertainment
Jamie Oliver
filmTV chef Jamie Oliver turned down role in The Hobbit
News
The official police photograph of Dustin Diamond taken after he was arrested in Wisconsin
peopleDownfall of the TV star charged with bar stabbing
PROMOTED VIDEO
Have you tried new the Independent Digital Edition apps?
Life and Style
tech
Arts and Entertainment
Jeremy Clarkson, left, and Richard Hammond upset the locals in South America
tvReview: Top Gear team flee Patagonia as Christmas special reaches its climax in the style of Butch and Sundance
News
people
Sport
Ashley Barnes of Burnley scores their second goal
footballMan City vs Burnley match report
News
news
Arts and Entertainment
Peter Mayhew as Chewbacca alongside Harrison Ford's Han Solo in 'Star Wars'
film
News
i100
Arts and Entertainment
Man of action: Christian Bale stars in Exodus: Gods and Kings
film
Life and Style
Apple showed no sign of losing its talent for product launches with the new, slightly larger iPhone 6 making headlines
techSecurity breaches and overhyped start-ups dominated a year in which very little changed (save the size of your phone)
Arts and Entertainment
Catherine (Sarah Lancashire) in Happy Valley ((C) Red Productions/Ben Blackall)
TV
Arts and Entertainment
Clueless? Locked-door mysteries are the ultimate manifestation of the cerebral detective story
booksAs a new collection of the genre’s best is published, its editor explains the rules of engagement
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
iJobs Job Widget
iJobs General

Recruitment Genius: Sales Consultant - OTE £30,000

£13000 - £30000 per annum: Recruitment Genius: Scotland's leading life insuran...

Recruitment Genius: Maintenance Assistant

£25000 - £30000 per annum: Recruitment Genius: A Maintenance Assistant is requ...

Recruitment Genius: Business Manager

£32000 - £40000 per annum: Recruitment Genius: A Business Manager is required ...

Recruitment Genius: Operations Manager

£45000 - £55000 per annum: Recruitment Genius: This is an exciting opportunity...

Day In a Page

A timely reminder of the bloody anniversary we all forgot

A timely reminder of the bloody anniversary we all forgot

Who remembers that this week we enter the 150th anniversary year of the end of the American Civil War, asks Robert Fisk
Homeless Veterans appeal: Former soldiers pay their respects to a friend who also served

Homeless Veterans appeal

Former soldiers pay their respects to a friend who also served
Downfall of Dustin 'Screech' Diamond, the 'Saved By The Bell' star charged with bar stabbing

Scarred by the bell

The downfall of the TV star charged with bar stabbing
Why 2014 was a year of technological let-downs

Why 2014 was a year of technological let-downs

Security breaches and overhyped start-ups dominated a year in which very little changed (save the size of your phone)
Cuba's golf revolution: But will the revolutionary nation take 'bourgeois' game to its heart?

Will revolutionary Cuba take 'bourgeois' golf to its heart?

Fidel Castro ridiculed the game – but now investment in leisure resort projects is welcome
The Locked Room Mysteries: As a new collection of the genre’s best is published, its editor Otto Penzler explains the rules of engagement

The Locked Room Mysteries

As a new collection of the genre’s best is published, its editor explains the rules of engagement
Amy Adams on playing painter Margaret Keane in Tim Burton's Big Eyes

How I made myself Keane

Amy Adams hadn’t wanted to take the role of artist Margaret Keane, because she’d had enough of playing victims. But then she had a daughter, and saw the painter in a new light
Ed Richards: Parting view of Ofcom chief. . . we hate jokes on the disabled

Parting view of Ofcom chief... we hate jokes on the disabled

Bad language once got TV viewers irate, inciting calls to broadcasting switchboards. But now there is a worse offender, says retiring head of the media watchdog, Ed Richards
A look back at fashion in 2014: Wear in review

Wear in review

A look back at fashion in 2014
Ian Herbert: My 10 hopes for sport in 2015. Might just one of them happen?

Ian Herbert: My 10 hopes for sport in 2015

Might just one of them happen?
War with Isis: The West needs more than a White Knight

The West needs more than a White Knight

Despite billions spent on weapons, the US has not been able to counter Isis's gruesome tactics, says Patrick Cockburn
Return to Helmand: Private Davey Graham recalls the day he was shot by the Taliban

'The day I was shot by the Taliban'

Private Davey Graham was shot five times during an ambush in 2007 - it was the first, controversial photograph to show the dangers our soldiers faced in Helmand province
Revealed: the best and worst airlines for delays

Revealed: the best and worst airlines for delays

Many flyers are failing to claim compensation to which they are entitled, a new survey has found
The stories that defined 2014: From the Scottish independence referendum to the Ice Bucket Challenge, our writers voice their opinions

The stories that defined 2014

From the Scottish independence referendum to the Ice Bucket Challenge, our writers voice their opinions
Stoke-on-Trent becomes first British city to be classified as 'disaster resilient' by the United Nations

Disaster looming? Now you know where to head...

Which British city has become the first to be awarded special 'resilience' status by the UN?