Bird populations in North America have dropped by 15 per cent in the last 40 years, according to a study published in the Science journal.
The same story is playing out across Europe, and it's been going on for decades.
Bird populations in North America have dropped by 15 per cent in the last 40 years, according to a study published in the Science journal.
The same story is playing out across Europe, and it's been going on for decades.