Cold War offered odd benefit -- it limited species invasions

January 7, 2010
Western Europe and Eastern Europe were divided along these boundaries during the Cold War, and more trade was internal, as indicated by the arrows, instead of between the two blocs. (Graphic courtesy of Oregon State University)

A recent study about movement of bird species during the Cold War outlines one of the perils facing an expanding global economy - along with international trade comes the potential for a significant increase in invasive species that can disrupt ecosystems.

The research found that during an extended period following , when most trade and travel was interrupted between Eastern Europe and its western counterparts, there were far fewer introduced bird species.

"Last year, people worldwide celebrated the 20th anniversary of the fall of the Iron Curtain and the end of the Cold War," said Susan Shirley, a research associate in the College of Forestry at Oregon State University. "This signified a time of renewed freedom and opportunities for the countries of Eastern Europe. However, those new opportunities brought new challenges from an unexpected source."

The problem, Shirley said, is that there's often a correlation between politics, trade and ecosystem function.

"Global trade is a real concern for invasive species, and the lessons we can learn from the Cold War offer a warning flag to developing countries that are now expanding in an international economy," Shirley said.

Control or eradication of invading species is extremely difficult and expensive, Shirley said, and prevention of animal importation is the only sure approach to address this problem. It relates not just to birds, which were the focus of this research, but to forest pests, fisheries, non-native crustaceans and many other species.

Even though birds, in theory, need pay little attention to international borders, in fact they tend to stay in native habitats. However, they sometimes establish populations in new locales if they are brought there, Shirley said.

"Traditionally we don't hear much about birds as an invasive species, but they can be," she said.

"The common myna, a subtropical bird, is a generalist predator and a crop pest, and has been included on a list of the 100 worst invasive species," Shirley said. "The collard dove is a habitat generalist and has now spread all over Europe. And of even more concern, there are several species with serious impacts in other regions of the world that may be in the process of establishing populations in Europe, largely due to the escape of wild-caught pet birds."

The study, published recently in the journal Biological Conservation, found that prior to the Cold War, Western Europe had 36 non-European introduced species and Eastern Europe had 11. By the time that period of international tension and restricted trade ended, Western Europe had experienced an increase to 54 non-European introduced bird species, but Eastern Europe had actually declined from 11 to five.

"The isolation of the Eastern European bloc from the west during the Cold War led to a decline in the number of birds introduced, the number of introduction events and the number of established," the study authors wrote in their report.

In light of that, the researchers suggest that clear policies need to be established to prevent further inflow of exotic species into previously isolated regions, and warn that the problems illustrated by this phenomenon in Europe may play out in similar ways all over the world as trade expands.

The unusual isolation of Eastern Europe for more than four decades provided a unique opportunity to study the effect of socio-economic and political factors on invasive species, the researchers said. In that context, eastern European ecosystems actually benefited from the isolation, scientists said, and also provide insight into how problems can be reduced with more aggressive regulation and monitoring.

Explore further: Threatened U.K. bird species has comeback

Related Stories

Bird species are saved from extinction

August 28, 2006

The first global audit of threatened species shows 16 species of birds nearly extinct in the mid-1990s have been saved, some increasing tenfold in number.

Invasive species threaten Canary Islands

August 29, 2006

The Canary Islands are reportedly being endangered by an invasion of foreign species that are overtaking the islands' unique plant and animal life.

European birds flock to warming Britain

July 30, 2008

Researchers at Durham, the RSPB and Cambridge University have found that birds such as the Cirl Bunting and Dartford Warbler are becoming more common across a wide range of habitats in Britain as temperatures rise.

11,000 alien species invade Europe

November 20, 2008

For the first time it is now possible to get a comprehensive overview of which alien species are present in Europe, their impacts and consequences for the environment and society. More than 11,000 alien species have been ...

Recommended for you

Trade in invasive plants is blossoming

October 3, 2015

Every day, hundreds of different plant species—many of them listed as invasive—are traded online worldwide on auction platforms. This exacerbates the problem of uncontrollable biological invasions.

Ancestral background can be determined by fingerprints

September 28, 2015

A proof-of-concept study finds that it is possible to identify an individual's ancestral background based on his or her fingerprint characteristics – a discovery with significant applications for law enforcement and anthropological ...

Bat species found to have tongue pump to pull in nectar

September 28, 2015

(—A trio of researchers affiliated with the University of Ulm in Germany and the Smithsonian Tropical Research Institute in Panama has found that one species of bat has a method of collecting nectar that has never ...


Adjust slider to filter visible comments by rank

Display comments: newest first

1 / 5 (1) Jan 07, 2010
Taking a long view; are "invasive" species harmful? Had the Horse not left North America, where it originated and where it later died out, there never would have been horses. Just saying.
5 / 5 (1) Jan 08, 2010
Um... Shootist, horses weren't in the Americas until the Spanish brought them.
not rated yet Jan 08, 2010
Horses originated in NA, migrated to Eurasia and later died out at about the same time as the mega-fauna (c.10kya).

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.