Sightings of blue tits, in particular, fell to a record low.

“Across the country, 22 per cent fewer blue tit sightings were registered per garden,” Lars Lachmann, a bird conservation expert of the Nature And Biodiversity Conservation Union (NABU), said on Tuesday.

One of the main causes was an outbreak of pneumonia-causing bacteria in spring that led to the deaths of an estimated 300,000 blue tits, one of Germany’s most common birds.

The bird census, which relied on data submitted by volunteers across Germany at the weekend, also delivered bad news for starlings and greenfinches, while sightings of wren also continued to fall.

There was better news for woodpigeons and collared doves, with both birds posting their highest number of sightings since the initiative started in 2005.

Sightings of jays and greater-spotted woodpeckers were also increasingly common, the census showed, but no species could match sightings of Germany’s most common bird: the house sparrow.

This year saw a record 120,000 people take part in the census by recording the bird life they spotted from their balconies, gardens, or in parks.