Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Climate change could increase levels of avian influenza in wild birds

30.08.2012
Rising sea levels, melting glaciers, more intense rainstorms and more frequent heat waves are among the planetary woes that may come to mind when climate change is mentioned. Now, two University of Michigan researchers say an increased risk of avian influenza transmission in wild birds can be added to the list.

Population ecologists Pejman Rohani and Victoria Brown used a mathematical model to explore the consequences of altered interactions between an important species of migratory shorebird and horseshoe crabs at Delaware Bay as a result of climate change.

They found that climate change could upset the carefully choreographed interactions between ruddy turnstone shorebirds and the horseshoe crabs that provide the bulk of their food during the birds' annual stopover at Delaware Bay, a major estuary of the Delaware River bordered by New Jersey to the north and Delaware to the south.

Climate change-caused disruptions to the well-timed interplay between the birds and crabs could lead to an increase in the avian influenza infection rate among ruddy turnstones and resident ducks of Delaware Bay, the researchers found. Because Delaware Bay is a crossroads for many bird species traveling between continents, an increase in the avian infection rate there could conceivably help spread novel subtypes of the influenza virus among North American wild bird populations, according to Rohani and Brown.

Their findings were published online Aug. 29 in the journal Biology Letters.

"We're not suggesting that our findings necessarily indicate an increased risk to human health," said Rohani, a professor of ecology and evolutionary biology, a professor of complex systems and a professor of epidemiology at the School of Public Health.

"But every single pandemic influenza virus that has been studied has included gene segments from avian influenza viruses. So from that perspective, understanding avian influenza transmission in its natural reservoir is, in itself, very important."

Avian influenza refers to infection with bird flu Type A viruses. Those viruses occur naturally among wild aquatic birds worldwide and can infect domestic poultry and other bird and animal species.

Avian flu viruses do not normally infect humans. However, sporadic human infections with avian flu viruses have occurred. Since 2003, for example, more than 600 cases—including more than 300 deaths—of human infection with highly pathogenic avian influenza A H5N1 have been reported worldwide, according to the World Health Organization.

Delaware Bay, which hosts many resident bird species as well as the hundreds of thousands of migratory birds that gather to feed on horseshoe crab eggs, is known as a hot spot for avian influenza virus. Infection levels in ruddy turnstones, which stop at Delaware Bay each May during their northbound migration to breeding grounds in the Arctic after wintering in South America, have been found to be exceptionally high.

The birds time their arrival at Delaware Bay to coincide with the availability of the horseshoe crab eggs. Brown and Rohani wondered what would happen to influenza levels in Delaware Bay birds if climate change altered the timing of the ruddy turnstone's migratory flight to Delaware Bay or affected the timing of horseshoe crab spawning.

Their mathematical model looked at virus infection rates in ruddy turnstones and two species of duck—mallards, which winter at the bay, and American black ducks, which live there year-round.

The researchers found that if ruddy turnstones reached Delaware Bay either several weeks earlier or later than their current May arrival date, influenza infection rates in the species increased significantly, driving up the infection rates—also called prevalence levels—in the resident ducks as well.

"If the ruddy turnstones arrive either earlier or later than they do now, then their arrival coincides with higher viral prevalence in the resident ducks," said Brown, a postdoctoral research fellow in the Department of Ecology and Evolutionary Biology and the Center for the Study of Complex Systems. "And because these birds are interacting with a greater number of infected resident ducks, prevalence levels in ruddy turnstones are boosted.

"There's a feedback mechanism at work as well. Higher prevalence levels in the ruddy turnstones may, in turn, impact the prevalence levels in the resident ducks, driving them even higher."

If the timing of the horseshoe crab spawning season at Delaware Bay changed significantly due to climate change, ruddy turnstone populations would drop significantly due to a loss of food, and the influenza infection rate would decrease sharply as well, the researchers found.

Delaware Bay was declared a site of hemispheric importance by the Western Hemisphere Shorebird Reserve Network in 1986. Sites of hemispheric importance act as staging, nesting or breeding grounds for at least 500,000 shorebirds annually, or at least 30 percent of the biogeographic population of any species.

Pejman Rohani:www.lsa.umich.edu/eeb/directory/faculty/rohani

Laura Lessnau | EurekAlert!
Further information:
http://www.umich.edu

More articles from Life Sciences:

nachricht Velcro for human cells
16.01.2019 | Albert-Ludwigs-Universität Freiburg im Breisgau

nachricht More efficient solar cells imitate photosynthesis
16.01.2019 | Friedrich-Alexander-Universität Erlangen-Nürnberg

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Flying Optical Cats for Quantum Communication

Dead and alive at the same time? Researchers at the Max Planck Institute of Quantum Optics have implemented Erwin Schrödinger’s paradoxical gedanken experiment employing an entangled atom-light state.

In 1935 Erwin Schrödinger formulated a thought experiment designed to capture the paradoxical nature of quantum physics. The crucial element of this gedanken...

Im Focus: Nanocellulose for novel implants: Ears from the 3D-printer

Cellulose obtained from wood has amazing material properties. Empa researchers are now equipping the biodegradable material with additional functionalities to produce implants for cartilage diseases using 3D printing.

It all starts with an ear. Empa researcher Michael Hausmann removes the object shaped like a human ear from the 3D printer and explains:

Im Focus: Elucidating the Atomic Mechanism of Superlubricity

The phenomenon of so-called superlubricity is known, but so far the explanation at the atomic level has been missing: for example, how does extremely low friction occur in bearings? Researchers from the Fraunhofer Institutes IWM and IWS jointly deciphered a universal mechanism of superlubricity for certain diamond-like carbon layers in combination with organic lubricants. Based on this knowledge, it is now possible to formulate design rules for supra lubricating layer-lubricant combinations. The results are presented in an article in Nature Communications, volume 10.

One of the most important prerequisites for sustainable and environmentally friendly mobility is minimizing friction. Research and industry have been dedicated...

Im Focus: Mission completed – EU partners successfully test new technologies for space robots in Morocco

Just in time for Christmas, a Mars-analogue mission in Morocco, coordinated by the Robotics Innovation Center of the German Research Center for Artificial Intelligence (DFKI) as part of the SRC project FACILITATORS, has been successfully completed. SRC, the Strategic Research Cluster on Space Robotics Technologies, is a program of the European Union to support research and development in space technologies. From mid-November to mid-December 2018, a team of more than 30 scientists from 11 countries tested technologies for future exploration of Mars and Moon in the desert of the Maghreb state.

Close to the border with Algeria, the Erfoud region in Morocco – known to tourists for its impressive sand dunes – offered ideal conditions for the four-week...

Im Focus: Programming light on a chip

Research opens doors in photonic quantum information processing, optical signal processing and microwave photonics

Researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) have developed a new integrated photonics platform that can...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Our digital society in 2040

16.01.2019 | Event News

11th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Aachen, 3-4 April 2019

14.01.2019 | Event News

ICTM Conference 2019: Digitization emerges as an engineering trend for turbomachinery construction

12.12.2018 | Event News

 
Latest News

Velcro for human cells

16.01.2019 | Life Sciences

Kiel physicists discover new effect in the interaction of plasmas with solids

16.01.2019 | Physics and Astronomy

The pace at which the world’s permafrost soils are warming

16.01.2019 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>