Beginning with the raptors (birds of prey) in March and culminating in Warbler Season in May, and then again from August through October, birds face an incredibly dangerous journey, flying between their summer nesting territory and their winter residences.

It’s always been dangerous for reasons related to weather and predation, but with the conditions imposed by us, it’s now a gauntlet. First we had the advent of guns and market hunting that, two centuries ago, began wiping many out. In the last century alone, communications towers and hydro lines and glass buildings and habitat loss and so on have amounted to Billions of birds lost.

The other day, I watched a documentary by New Hampshire Public Television on bird migration. I learned a few startling facts about habitat loss and other pressures that decimate bird populations. Most alarming of all was that bird mortality while migrating is as high as 85%. I doubt that’s due to hurricanes and low seasonal food, though these are real risks that birds have always faced. I’m sure that most are due to human activity:

• Building and tower lights on at night throwing birds off course, exhausting and killing them. Birds migrate at night, and the light of the moon used to guide them. Now, our overlit cities and buildings misguide them.
• Bird strikes on power and cellular telephone infrastructure — guy wires and towers also are responsible, it’s not just wind turbines.
• Critical habitat loss on migration routes. Birds need to land and feed, timed with their food source according to the season and weather, before proceeding north (or south) again.
• Bird strikes on buildings, now more than ever. Glass architecture is killing millions of migratory birds. And it’s not just big buildings! An individual home may only be killing a handful of birds a year, but there are so many homes out there that those numbers really add up quickly.
• And the grand winner: Our pet and feral cats are the biggest killers by far. Do not underestimate the carnage that your sweet kitty causes. It’s not good fun. If you absolutely insist on putting your cat outdoors – you’re wrong, but still – do it only at night, when birds are in flight. During the day, they need to come down and search for food, water, and rest. They need it. The cat’s just playing. (So put a BirdBeSafe collar on kitty!)