Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Bird diversity lessens human exposure to West Nile Virus

A study by biologists at Washington University in St. Louis shows that the more diverse a bird population is in an area, the less chance humans have of exposure to West Nile Virus (WNV).
Now, let's hear it for the birds.

When the red, red robin comes bob, bob bobbin' along, think West Nile Virus (WNV). Robins are anthrophilic - they love being around humans - and it's relatively easy for mosquitoes to take their blood meals from them because robins feed so much on the ground, making them a very common reservoir species for transferring WNV to humans.

"The bottom line is that where there are more bird species in your backyard, you have much lower risk of contracting West Nile fever," said Brian Allan, doctoral candidate in biology in Arts & Sciences at Washington University in St. Louis. "The mechanisms are similar to those described for the ecology of Lyme disease. Most birds are poor reservoirs for West Nile Virus, and so mosquito bites taken on them are 'wasted' from the perspective of the virus. Where many bird species exist, very few mosquitoes get infected, and so we humans are at low risk. A few bird species are highly competent reservoirs, and these tend to occur in urbanized and suburbanized areas where bird diversity suffers."

The most common "reservoir" species that urbanites and suburbanites and even rural dwellers in heavily farmed landscapes see are crows, grackles, house finches, blue jays, sparrows and American robins, with the robin being the most prolific carrier of WNV. Robins are anthrophilic — they love being around humans — and it's relatively easy for mosquitoes to take their blood meals from them because robins feed so much on the ground.

Allan, his advisor Jonathan M. Chase, Ph.D., associate professor of biology, and 14 collaborators from numerous institutions will publish their findings in a forthcoming issue of Oecologia.

While diversity of bird species is important in this scenario, that factor alone doesn't tell the whole story.

"It's not just about the number, but their relative proportions," Allan said. "It's a combination of richness - the number of species — and evenness — their relative proportions. In urban and suburban areas you see lower species richness and lower community evenness. For instance, you might have five species present, but in 100 animals 90 are just one species. That's why species number is only half the equation."

Allan and numerous graduate students began the research five years ago as they just entered graduate school and the topic of West Nile Virus was just beginning to receive lots of attention and the ecology of the organism hadn't been studied much. They identified a variety of field sites, both urban and rural, with their base of operations at Washington University's Tyson Research Center, a facility 22 miles west of St. Louis comprised of 2,000 acres of woods, glades and prairie.

They performed bird surveys at the sites, put up a variety of mosquito traps and studied different mosquito species and their ability to transmit the virus. Using kits provided by the Center for Disease Control, they tested the mosquitoes and found three positive pools.

"The infection rates are actually remarkably low, with maybe one in 1,000 carrying WNV," Allan said.

They expanded their study to include mosquito infection data from the St. Louis City and St. Louis County Health departments. They saw the same patterns. The greater bird diversity, the lesser incidence of WNV; the lesser diversity, the greater likelihood of WNV.

To broaden their finding even more, Allan and his colleagues used national data sets on human cases of WNV and a tool called the Shannon Diversity Index to estimate the diversity of bird populations across the U.S. These data are conducted nationwide by amateur bird watchers for the United States Geological Survey's Breeding Bird Surveys.

"We're seeing locally and nationally that bird diversity is a buffer against the occurrence of West Nile Virus in humans," Allan said. "That's a win-win situation for both conservation and public health."

Brian Allan | EurekAlert!
Further information:

Further reports about: Bird diversity Lyme disease WNV West Nile virus bird population bird species

More articles from Studies and Analyses:

nachricht Diagnoses: When Are Several Opinions Better Than One?
19.07.2016 | Max-Planck-Institut für Bildungsforschung

nachricht High in calories and low in nutrients when adolescents share pictures of food online
07.04.2016 | University of Gothenburg

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

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

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

'Neighbor maps' reveal the genome's 3-D shape

27.10.2016 | Life Sciences

Gene therapy shows promise for treating Niemann-Pick disease type C1

27.10.2016 | Life Sciences

Solid progress in carbon capture

27.10.2016 | Power and Electrical Engineering

More VideoLinks >>>