A study conducted on bird populations in Europe found that there are significantly less birds living on the continent than there were in the 1980s.
Over the past 30 years, the number of birds living in Europe has dropped astronomically.
A study conducted by scientists from the U.K. and Czech Republic found that there are 421 million less birds across the continent than there were in the beginning of the 1980s.
The decline is being attributed to the birds' natural habitats being damaged or destroyed by the construction of urban environments and the expansion of farmland.
The study utilized thousands of surveys on birds that have been taken over the past three decades, in 25 different European countries.
The most common species of birds, including sparrows, skylarks and starlings, saw the most significant drop in their populations.
Out of these, there were around 2.06 billion back in 1980, and only 1.64 billion in 2009, which was the last year examined in the study.
According to the co-leader of the study, Richard Gregory, "This is a warning from birds throughout Europe. It is clear that the way we are managing the environment is unsustainable for many of our most familiar species."
Rarer birds haven't suffered as much, likely due to stricter conservation efforts, something now urged by researchers for all the species.