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
Trees and climate change: Faster growth, lighter wood
14.08.2018 | Technische Universität München
Animals and fungi enhance the performance of forests
01.08.2018 | Deutsches Zentrum für integrative Biodiversitätsforschung (iDiv) Halle-Jena-Leipzig
Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...
Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.
When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...
Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.
Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....
Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.
Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...
Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur
What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...
08.08.2018 | Event News
27.07.2018 | Event News
25.07.2018 | Event News
16.08.2018 | Earth Sciences
16.08.2018 | Life Sciences
16.08.2018 | Materials Sciences