Navigation Links
Undesirable expatriates: Preventing the spread of invasive animals

Reconsider relocating aquarium fish into your backyard pond. Restrain yourself from ordering exotic pets off the Internet, no matter how interesting they might look in the pictures. And vote for politicians that encourage sound port inspection. Because, according to recent Proceedings of the National Academy of Sciences article by Drs. Jonathan M. Jeschke and David L. Strayer, our best defense in combating invasive animals is ensuring that they don't infiltrate our natural areas in the first place.

Defined by the authors as animals that have established and spread outside of their native range, many invasive species become economic and ecological burdens. Successful invaders can displace native animals through resource competition, predation or disease-- ushering in biodiversity loss. Globally, invasive species are the second leading cause of animal extinction, preceded only by habitat loss.

Not all introduced animals become invasive. When moved into a foreign environment, many animals find conditions unfavorable and fail to establish. In an effort to gain insight into how frequently introduced animals become invasive, Drs. Jeschke and Strayer analyzed bird, mammal and freshwater fish introductions between Europe and North America. Jeschke comments, "We focused our study on larger vertebrates because there are better historical records about their introductions, which were often done purposefully for human use."

While motivations vary-- some animals make great pets, others have valuable pelts-- humans have been moving animals between Europe and North America for hundreds of years. Enterprising furriers imported American mink into Europe, where the animals escaped from captivity and spread prolifically. European mink have been suffering ever since. Other animals have been introduced unintentionally. Rats were stowaways on the first vessels sailing from Europe to North America. They now flourish in urban and agricultural areas, causing approxima tely $19 billion dollars worth of damages annually in the U.S. (Pimentel et al. 2000. BioScience 50, 53).

The authors' exhaustive analysis, which drew on data from the 15th century to the 20th century, revealed an unsettling conclusion. For every four animals that made the transatlantic journey, one became invasive. Jeschke notes, "Our data indicate that once introduced, vertebrates have a 25% chance of becoming invasive. This figure, which appears to be true for other animals as well, is significantly higher than the 1% probability that dominates invasive species risk assessment. The 1% probability is based on plant invasions. Introduced animals do not act like introduced plants-- they appear to have a much higher invasion success rate."

Given that humans are the primary vehicles for transporting animals across the ocean, it's not surprising that animal introduction patterns between Europe and North America mirror immigration patterns. Overall, a higher proportion of European animals entered North America than vice-versa, with introductions peaking in the 19th century and decreasing thereafter. This decline can be attributed to a reduction in immigration following WWI and increased U.S. regulations on wildlife imports.

Conversely, North American introductions to Europe have been on the rise throughout the 20th century as more Americans immigrate to European countries. In many parts of Europe, regulations on imported wildlife are not as strict as the U.S. and Canada. Canadian goose, gray squirrel, and northern cottontails already populate the European countryside. In the absence of precautions, Jeschke speculates that North American animal introductions may become more common.

The bottom line-- vertebrate animals have a high rate of invasion success. Once established, they can act as biological pollutants that result in ecological and economic damages. "The best way to combat invasive species is to prevent them from being introduced. As global trade increases, precautions like port inspection and exotic wildlife regulations are essential. Consumers also need to be educated; many exotic animals that are legal as pets could be ecologically lethal if released into the wild."

Future research will explore why, once introduced, animals are more likely than plants to become invasive.


'"/>

Source:Institute of Ecosystem Studies


Related biology news :

1. Size matters: Preventing large mammal extinction
2. Preventing a pandemic: Study suggests strategies for containing a flu outbreak
3. Anti-bacterial additive widespread in U.S. waterways
4. HIV-1 spread through six transmission lines in the UK
5. Reservoirs may accelerate the spread of invasive aquatic species, researchers say
6. Nanobacteria in clouds could spread disease, scientists claim
7. Rabies spread speeds up
8. New understanding of cell movement may yield ways to brake cancers spread
9. VCU Massey Cancer Center study shows enzyme linked to spread of breast cancer cells
10. Industrial contaminants spread by seabirds in High Arctic, new Canadian study shows
11. Past droughts geographically widespread in the West, according to tree-ring data
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:1/22/2016)... http://www.researchandmarkets.com/research/p74whf/global_biometrics ) ... "Global Biometrics Market in Retail Sector 2016-2020" ... --> http://www.researchandmarkets.com/research/p74whf/global_biometrics ) has announced the ... in Retail Sector 2016-2020" report to ... and Markets ( http://www.researchandmarkets.com/research/p74whf/global_biometrics ) has announced ...
(Date:1/20/2016)... , Jan. 20, 2016  Synaptics Incorporated (NASDAQ: ... interface solutions, today announced sampling of S1423, its ... wearables and small screen applications including smartwatches, fitness ... Supporting round and rectangular shapes, as well as ... performance with moisture on screen, while wearing gloves, ...
(Date:1/13/2016)... , January 13, 2016 ... the addition of the  "India Biometrics ... & Forecast (2015-2020)"  report to ... ) has announced the addition of ... Market - Estimation & Forecast (2015-2020)" ...
Breaking Biology News(10 mins):
(Date:2/9/2016)... 2016 BERG, a biopharmaceutical company uncovering ... has announced the appointment of Jason Haddock ... Officer. Haddock brings to BERG over 20 years ... in senior financial functions at pharmaceutical companies, as ... management. Niven R. Narain , ...
(Date:2/8/2016)... -- --> --> ... company developing next generation cancer therapeutics that are ... chairman emeritus of Tata Sons Limited, Mr Ratan ... part of the first close of Invictus,s Series ... and Aarin Capital. http://photos.prnewswire.com/prnh/20150923/766442 ) , ...
(Date:2/8/2016)... ... February 08, 2016 , ... ... of loose, bulk foods at various stages of the production process. Despite frequently ... inspect large bulk products post packaging such as sacks of dry powders. , ...
(Date:2/8/2016)... -- --> --> ... ultra-rapid Point-Of-Care (POC) molecular diagnostics company, today announces that it ... test to be launched on the Company,s io® platform. By ... test is now cleared for sale within the European Union. ... of the io® CT test signals a new era in ...
Breaking Biology Technology: