In 1970 I was young and the family I had then moved to this place broadly speaking. Fifty years ago.

It never seemed to me then that there were too many birds. The passenger pigeons had all been killed off long before. The North American continent so-called was well on its way to being overdeveloped. The condition of habitat wasn’t pretty. But even so.

From then until now, there are three billion birds less. Just on this continent. Three billion.

That’s about a third of them.

“Three billion is a punch in the gut,” says Peter Marra, a conservation biologist at Georgetown University in Washington, D.C. The loss is widespread, he says, affecting rare and common birds alike. “Our study is a wake-up call. We’re experiencing an ecological crisis.”

Yes we are.

Alongside a spiritual one, an existential one, and a few others.

Three billion, disappeared.