28 June 2013

German KP update

In the past the majority of recoveries received at the BTO concerned reports of dead birds, so reports where live birds were reported were few and far between. With the advent of colour ringing, particularly of raptors, waders and gulls, the chance of getting reports which track the movements of birds has greatly increased. 

Kentish Plover taken by Martin Casemore

We posted in March about a Kentish Plover that was ringed in Germany as a breeding adult at St Peter-Ording (Schleswig-Holstein, Germany) in May 2009 (red pin). It returned to the same site again in June 2010, and was then seen in Sussex in March 2013 (yellow pin). This is valuable information in itself but it has now been reported on 24 June 2013 on the Eider Estuary (blue pin), Schleswig Holstein, Germany.

View Kentish Plover in a larger map

We still don't have much information regarding KPs that visit the UK or Ireland, so this information is very interesting. Hopefully we'll get to see this bird once again on our shores.

Thanks to Dominic Cimiotti for letting us know.

21 June 2013

Trichomonosis insight

The impact that diseases have on bird populations is a fascinating topic of research, to which ringers and members of the public can contribute. Many will now be aware of the detrimental effect that Trichomonosis has had on Greenfinch populations in the UK, a relationship established by a piece of research led by scientists at the Institute of Zoology in London and the BTO. A subsequent study from the same team also showed, through molecular analyses, that the disease arrived in Fennoscandia from the UK in 2008, most likely carried by Chaffinches. This link was identified thanks to the known migration route of this species provided by previous ringing data.

Greenfinch showing signs of Trichomonosis by Heather Povey
A project by different authors has recently showed that Trichomonosis spread in Finland in 2008 and 2009 and impacted local Greenfinch and Chaffinch breeding populations. In August-September 2008 the first cases of this disease had appeared in the country, followed by a peak in reported mortality in July 2009, although cases diminished in 2010 to pick up again in 2011. The Finnish study showed that population of breeding Greenfinch declined by 47% in south Finland, but not other parts of the country, at the peak of the outbreak between 2009 and 2010, whilst Chaffinch declined by 4%, between 2006 and 2010, the first population decrease since 1984. Bird body condition was also affected by the disease. Ringing data highlighted that Greenfinches, especially juveniles, were lighter than usual over the autumns 2008 and 2009 in the areas most affected by Trichomonosis.

These studies are a very good example of the important contribution to science that members of the public and ringers provide by reporting changes in birds and garden wildlife, as well as the unique high-quality data and essential information that ringing provides.

For more background information, visit the BTO GBW webpage

Daria Dadam, Research Ecologist

06 June 2013

Lost Sedge Warbler Czechs in

Considering the hazards of migration and the massive distances involved, it's quite amazing that birds make it back to breeding sites year on year. But just occasionally there's a bird that bucks the trend... One such bird was Sedge Warbler Y931333, originally ringed on migration in Sussex on 1st August 2012. It presumably spent the winter in sub-Saharan Africa, but was recaught on 4th May by ringers at Lázně Bohdaneč in the Czech Republic. When recaught this bird was sexed as a female, so was presumably in breeding condition, so why it was migrating through Sussex in a previous year is a mystery.

The BTO's online ringing report (with the map below) shows that this is actually the furthest east recovery of a British-ringed Sedge Warbler from over 100 years of ringing, beating the previous bird which is the only other British Sedge Warbler to be found in the Czech Republic. Coincidentally, this bird was also ringed at the same site in Sussex, in August 2003!