Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Bird brains shrink from exposure to contaminants

17.07.2006
The regions in robins' brains responsible for singing and mating are shrinking when exposed to high levels of DDT, says new University of Alberta research--the first proof that natural exposure to a contaminant damages the brain of a wild animal.

"These residues have been persisting since the late 1960s--that's what is really disturbing," said Dr. Andrew Iwaniuk, a post-doctoral research fellow in the U of A's Department of Psychology. "It has been years since it has been used and still has this effect."

The new research, published in Behavioural Brain Research, strongly suggests that exposure to environmental levels of DDT causes significant changes in the brains of songbirds.

Previous studies have suggested that exposure to DDT residues affect the brain, but none have actually demonstrated it. The research team, including Iwaniuk's supervisor, psychology professor and Tier II Canada Research Chair Douglas Wong-Wylie, used American Robins to test the idea. Birds are more susceptible to the effects of pesticide residues and other contaminants in the environment than other animals. As well, American robins are often exposed to high levels of DDT and other chemicals because they rely heavily on earthworms as part of their diet. They specifically chose these birds in the Okanagan Valley because at that location they are exposed to high levels of DDT, but relatively low levels of other chemicals.

The researchers captured 18 nestlings and then hand-reared and observed them for two years. They then sectioned the brains and examined the size of several brain regions. "We found that the regions sensitive to reproductive hormones--song production and courtship behaviour--were most affected by DDT," said Iwaniuk. "Song production is extremely important in attracting a mate or to mark out a territory.

"The issue is not that DDT is killing these robins but if they are growing up in this one area and then move to another, they won't be able to attract any females."

These effects were most prominent in the males, some of which experienced up to a 30 per cent reduction in brain region size compared to males at lower DDT exposure levels.

Whether this also applies to other animals and humans is unclear because there is not yet a strong understanding of how these chemicals in the environment affect the brain, but it is possible that humans exposed to similar levels of DDT will also be at risk of neurological damage.

"The take-home message is that people need to be more cognizant of their use of pesticides and herbicides," said Iwaniuk. "People need to be careful about using chemicals in their homes or farms. Who knows the effects these will have down the road."

Phoebe Dey | EurekAlert!
Further information:
http://www.ualberta.ca

More articles from Life Sciences:

nachricht New risk factors for anxiety disorders
24.02.2017 | Julius-Maximilians-Universität Würzburg

nachricht Stingless bees have their nests protected by soldiers
24.02.2017 | Johannes Gutenberg-Universität Mainz

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>