A story in the morning newspaper highlights a loss so subtle, it may have escaped your notice. During the past 40 years, according to the most recent survey, about 1.5 billion of North America’s land birds – out of a population of about 11.5 billion – have disappeared from our skies.

The causes are complex: urban expansion, changes in agriculture, and climate change, among others. Some declines remain mysterious. Why are so many “aerial insectivores” – birds that eat insects – disappearing? Are there really fewer insects flitting overhead or smearing car grilles now, compared to 40 years ago? And if that’s true, what does it say about our environment?

In short, it suggests we have significant problems. As a group, birds tend to be well adapted to their environment. So when 86 of North America’s 450-odd breeding bird species are vulnerable to outright loss, that’s a symptom of rapid and widespread change on our shared landscapes. As the report, Partners in Flight Landbird Conservation Plan reads, “birds are excellent indicators of overall environmental health—and their loss signals danger.” Continue reading →