Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Bird flu: the wildfowl trail

02.04.2007
How does the highly pathogenic bird flu virus spread to new countries? Might the domestic bird trade be responsible? Or is it wildfowl? Since last year, a team from CIRAD has been working on wildfowl.

To date, the virus has not been detected in healthy wild birds, but many dead or dying birds have been found near infection foci. Are they victims or reservoirs? In all likelihood the former, but the latter hypothesis cannot be ruled out. Six healthy ducks carrying the virus - out of a total of 4600 tested and in a particularly severely infected zone - were found in China in January 2005.

Determining the number of stages and where birds stop off during migration

In 2005 and 2006, migrating birds were often under suspicion. However, their migration corridors and periods did not necessarily correspond to the virus spread patterns seen in recent years. To clarify matters, researchers are now plotting comprehensive, accurate flight plans. To this end, with FAO funding, they are fitting birds with small Argos transmitters. This equipment will provide a large number of data and fill the gaps in information on the subject. Migration has already been studied in detail in Europe and Asia, but this is far from the case in Africa, where monitoring is limited to counting the populations in each country or ringing birds, despite the fact that some five million ducks from Eurasia winter in Subsaharan Africa and there are more than four million African ducks that fly between the different regions of the continent.

In particular, the transmitters will provide information on the number of migration stages and where the birds stop off during migration. In fact, they stop off in humid zones propitious to pathogen transmission, where the different species mix with one another. The study should also provide more general information on migration: travelling times and the ecological and manmade factors that determine the stops.

Three species in three African countries

Three species were chosen for the operation: the blue-winged teal, fulvous whistling duck and comb duck, each of which represents a typical migration route. The teal is a Europe-Asia-Africa intercontinental migrator and winters exclusively in Subsaharan Africa, where it is the most common wintering bird. The comb duck restricts its movements to Africa, but covers several regions, while the fulvous whistling duck, the most common African duck, is a nomadic species on a regional level. The researchers' first step was to test the impact of the transmitters on the birds' behaviour in captivity at Montpellier's Lunaret Zoo. They then travelled to Africa, and captured and equipped 45 birds in February. Captures were made at three sites: northern Nigeria, a very humid zone where there have been bird flu foci for more than a year; the inland delta of the Niger River, in Mali, which is the biggest wintering site for Eurasian ducks in Africa; and Malawi, which had the necessary sites for a study of interregional migration. Now that the birds have been released, they can be monitored, and the results, updated twice weekly, are now available on a CIRAD website: http://wildbirds-ai.cirad.fr.

On-line maps for real-time monitoring

The study is a first for Africa. Teams from the FAO and the United States Geological Survey, which work with CIRAD, have also equipped swans in China and Mongolia. For the time being, the researchers do not know how long the transmitters will continue to supply data (this depends on the birds' lifespan).

Each transmitter weighs between 12 and 30 grammes. The 12- and 18-gramme ones are used for teals and fulvous whistling ducks, and the 30-gramme ones for comb ducks, which are larger. They are fitted to the body of each bird, like small backpacks, using teflon straps. The location of each bird is determined using the Argos system. The transmitter emits a signal that is picked up by satellites in polar orbit at a height of 850 km. The satellites then send the signal back to terrestrial reception stations. The data received are subsequently processed by centres specializing in the Argos system. Lastly, once processed, the data are passed on to users.

The maps available on the Wild birds and avian influenza in Africa website can be used to monitor bird movements, virtually in real time. At the moment, the teals from Nigeria are moving towards Lake Chad. They should be heading north in the next few days.

Helen Burford | alfa
Further information:
http://www.cirad.fr/en/actualite/communique.php?id=667

More articles from Agricultural and Forestry Science:

nachricht Light green plants save nitrogen without sacrificing photosynthetic efficiency
21.11.2017 | Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign

nachricht Filling intercropping info gap
16.11.2017 | American Society of Agronomy

All articles from Agricultural and Forestry Science >>>

The most recent press releases about innovation >>>

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

Im Focus: Frictional Heat Powers Hydrothermal Activity on Enceladus

Computer simulation shows how the icy moon heats water in a porous rock core

Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Underwater acoustic localization of marine mammals and vehicles

23.11.2017 | Information Technology

Enhancing the quantum sensing capabilities of diamond

23.11.2017 | Physics and Astronomy

Meadows beat out shrubs when it comes to storing carbon

23.11.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>