June 20, 2008

Genetic analysis of migration in
Tufted Duck and Common Pochard

Tufted Duck. Photo © Martin Semisch

The current knowledge about migration patterns in Eurasian Aythya ducks is entirely based on the limited information available from the analysis of bird counts and ring recovery data. In Europe, bird ringing activities are coordinated by the European ringing scheme EURING, where the data are centrally governed. These data suggest movements between different duck populations, which would facilitate the spread of viruses. However, the extent of these interactions is difficult to quantify with ring recovery data. I'm carrying out a project of the detailed genetic analysis of migration in two Eurasian Aythya species, Tufted Duck A. fuligula and Common Pochard A. ferina to provide exactly this missing information.

Common Pochard. Photo © Martin Semisch

From genetic data, it is possible to assess the extent of gene flow between different populations and to assign individuals to particular genetic subpopulation. In other words, we can simultaneously estimate the long-term average rate of gene flow and document actual dispersal events. The primary goal is to provide a solid basis for assessing the risk of H5N1 introduction into Switzerland by migratory ducks. The two target species from the genus Aythya are prime candidates as long distance vectors because of the large number of birds migrating between Central Europe and Asia each year, the potential mixing of birds wintering in Southeast Asia and Europe on their Northern Asian breeding grounds, and the high incidence of H5N1 in Aythya in Switzerland. Detailed knowledge about the population of origin of infected birds, the time of arrival of birds from populations in high risk areas, and the relative proportion of such birds among the winter guests in Switzerland will allow the efficient monitoring of infection risks, and consequently a much more informed and sensible implementation of protective measures for poultry.

Tufted Duck. Photo © Martin Semisch

Feather/ tissue/ blood samples from two species will be collected from different locations across the entire distribution range of the two species in Eurasia. The coverage of both breeding grounds and wintering grounds will provide representative samples of the genetic diversity in these ducks. We are highly appreciated anyone who is likely to provide our samples.

Common Pochard. Sketch © Nikolai Kranais. www.birdsart.de

The followings are what we need and some information concerned with sampling protocol.

1) Our main interest is in samples from birds' breeding or wintering area. As we will mainly focus on very large-scale patterns the exact sampling location within this region is less relevant. Therefore, the samples can be from one or several locations depending on what is easier for you.

2) The samples should be collected during wintering or breeding period, but samples collected at other times will also be very welcome.

3) Feather samples will be sufficient for all our analyses. I assume that feathers will also be easier to collect in the field than blood or tissue samples. If samples of tissue and blood are possible, they are highly welcome because of their high DNA concentration.

4) It is important that the feathers (rectrices or inner primaries are ideal parts) are plucked from the bird. This is to ensure that small amounts of tissue are attached to them which can be used for the DNA analyses. As long as the feathers are dry they can simply be stored in paper envelopes for each individual separately. The number of feathers required per individual depends a bit on their size. Four large feathers or 10 small feathers should be sufficient.

5) I'm interested in all individuals (males, females, 1st years, adults). Depending on the number of samples that can be collected it may then be possible to look at sex- or age-specific differences. 15~30 individuals from each age or sex group for each species are perfect if possible.

To summarize, it would be very helpful to have any samples from these two species that you may be able to obtain. It would be important to know the following information for each sample:

- species of the bird
- sampling location (ideally coordinates, or the name of the nearest town)
- sex of the bird
- age of the bird (if possible)
- date of sample collection

Tufted Duck. Photo © Martin Semisch

All samples can be sent to

Yang Liu, PhD student
CMPG, Zoologisches Institut
Universitaet Bern
Baltzerstr. 6
CH-3012 Bern

Email: yang.liu at zoo.unibe.ch

Please feel free to let me know if you have additional questions. Comments
related to this project are also welcome. Thanks very much for your
attention and assistance of sampling for this project.

Sincerely yours

Liu Yang

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