More than 11,000 cases of dead and sick birds reported in past fortnight

Thousands of blue tits have been found sick or dead in Germany, prompting an investigation by conservation groups and scientists.

More than 11,000 cases of dead and sick birds, mostly blue tits, have been reported to the German conservation group NABU in the past fortnight. Most of these are reported from the west of Germany.

The blue tit is found across Europe and is one of the most common visitors to UK gardens. They eat insects, caterpillars, seeds and nuts and can be spotted all year round in the UK, with the exception of some Scottish islands.

According to NABU, symptoms of the diseased birds include breathing problems, no longer taking food and making no attempt to escape when approached by people. The group is advising people to stop feeding or providing drinking troughs for birds to reduce the risk of transmission between them.

The first laboratory test results on the dead birds have found a bacterial infection (Suttonella ornithocola) that has been known in the UK since the 1990s and which affects birds similarly. The infection was reported in Germany in 2018. Further test results on birds are expected over the next few days.

The infection discovered causes pneumonia in tits – predominantly blue tits – and they become lethargic with fluffed-up plumage and breathing difficulties. There are no reports of this affecting any other animals apart from birds.