Bird flu is back – and this autumn it is primarily affecting cranes in Germany. Hundreds of dead animals have been discovered at several large rest areas in recent days. The Friedrich Loeffler Institute estimates the risk of further outbreaks to be high – especially because the peak of autumn bird migration is still to come. But what can be done to prevent further spread?
Bird flu, also known as avian influenza, is a highly contagious viral infection that quickly causes death in many bird species. It is triggered by variants of the avian influenza virus, usually the H5N1 subtype. In the past, the disease has repeatedly led to large losses in wild bird populations and to mass culling in poultry farms. A particularly aggressive variant of the H5N1 virus has been rampant for several years and has already spread worldwide and in some cases can also affect mammals.
More dead cranes than ever before
This fall, H5N1 is spreading rapidly again, boosted by annual bird migration. With it, infected birds are increasingly coming back to Central Europe. Cranes are particularly hard hit on their migration to their winter quarters. According to authorities, up to a thousand animals could have died at the Linum ponds in Havelland, Brandenburg alone, and hundreds of dead birds were also found at other resting places such as the Kelbra reservoir in Saxony-Anhalt or Lake Galenbeck in Mecklenburg-Western Pomerania. In total, the authorities currently assume that around 2,000 cranes have died – more than ever before in one autumn. But this number is likely to continue to rise as the peak of the crane migration is yet to come.
The Friedrich Loeffler Institute (FLI), the Federal Research Institute for Animal Health, warns: “Due to the current strong migratory activity of crane populations and other wild birds, a further, possibly large-scale spread of infections must be expected in the near future.” In addition to cranes, various species of water birds, including wild ducks and geese, are particularly affected. Because they are no longer quite as susceptible due to past contact with pathogens, they can sometimes survive bird flu and become less seriously ill. However, this means they can infect other birds. The FLI therefore assesses the risk of further outbreaks as high. Commercial poultry farms are also affected: In several regions, tens of thousands of chickens, turkeys and ducks have already had to be culled to prevent further spread.
What can be done about it?
In order to contain the situation, poultry farmers are currently being asked to strictly protect their animals from wild birds and to consistently implement hygiene measures. At migratory bird resting places, carcasses of dead birds are also removed as quickly as possible to prevent scavengers such as crows, sea eagles or foxes from also becoming infected. The nature conservation association NABU also asks nature lovers to avoid visiting the crane resting places in order not to spread viruses through feces stuck to their shoes. According to the FLI, there is currently no particular risk for humans as long as there is no direct contact with dead or sick birds.
“We have to monitor what is happening carefully and take all security measures,” said Christa Kühn, President of the FLI, to the Reuters news agency. The risk of further spread of bird flu is high, but can still be avoided. “We are not in a situation where we say everything is out of control.”
Source: Friedrich Loeffler Institute (FLI), NABU