A new study published in the journal Science on Thursday shows that species of birds which were once commonplace in North America are vanishing. According to the ambitious study, which looked at over 500 species of birds, there has been “a net loss approaching 3 billion birds, or 29 percent” since 1970, with population losses “from most biomes” across much of North America. That means there are 2.9 billion fewer birds now than there were about 50 years ago. “It’s just staggering... It’s across the board,” said Kenneth V. Rosenberg, a conservation scientist at Cornell University and the study’s lead author. “This loss of bird abundance signals an urgent need to address threats to avert future avifaunal collapse and associated loss of ecosystem integrity, function and services,” reads the study’s abstract.

“Declines in your common sparrow or other little brown bird may not receive the same attention as historic losses of bald eagles or sandhill cranes, but they are going to have much more of an impact,” said Hillary Young, a conservation biologist at the University of California, Santa Barbara. The study was not intended to determine a reason for the decline, but results did point to habitat loss and pesticides as major contributing factors. To address the problem, the Audubon Society has called for the protection of habitats that are still brimming with birds, and to safeguard the Migratory Bird Treaty Act, a century-old law that the Trump Administration is trying to repeal.