One recent morning, as I walked from the house to the driveway, I noticed a pile of bird feathers scattered beneath one of my feeders.

“Damned cat,” I muttered, looking to see if the culprit, a feline of unknown ownership who roams the neighborhood from dusk to dawn, was still skulking somewhere among the hostas.

The cat was long gone. So, for that matter, was the bird – judging from the feathers, it was a black-capped chickadee.

Discovering the occasional dead bird in one’s yard doesn’t rank up there among life’s major tragedies. At least until now.

Last week’s news from the bird world was, for anyone who takes even a passing interest in our feathered friends, nothing short of stunning.

According to a just-released study by the Cornell Lab of Ornithology and the American Bird Conservancy, the bird population in the United States and Canada fell by nearly 30 percent over the last 50 years.

That’s 2.9 billion fewer birds filling our skies today compared to 1970.

And that, according to Doug Hitchcox, the staff naturalist at Maine Audubon, spells trouble ahead.

“Birds are indicators of the health and stability of our ecosystems,” Hitchcox said Friday afternoon amid the tranquility of Maine Audubon’s Gilsland Farm in Falmouth. “If birds are declining, that means that there are bigger problems going on.”

Hitchcox is, without doubt, a bird guy. On this day, he wore a T-shirt with the invitation “Let’s go birding together” emblazoned across the front. Which, it turns out, he’s always doing.

“Look, there’s an osprey flying over carrying a fish,” he said, pointing skyward as the majestic raptor passed over the farm.

Then, a few minutes later: “Oh! A night hawk! Look at that – flying right over the building here, going right past that puff of clouds! It’s only the second or third time I’ve seen one on this property!”

The bird study combined decades of dutiful counting by an army of birders with data culled from weather radars. It produced what is widely heralded as the most reliable database to date on the overall state of bird populations here and in Canada.

For Hitchcox, whose career centers on Maine’s diverse array of bird species, the study comes at a time, ironically, when interest in birds seems to be soaring ever higher.

Take, for example, the free bird walks Hitchcox conducts each May – the peak of the spring migration – at Portland’s Evergreen Cemetery. The pond at the rear of the cemetery has long been a magnet for a cadre of hardcore bird lovers, but this year the gatherings averaged 60 people per walk.

“It’s insane,” Hitchcox said. “I don’t know how the 60th person could even hear what I was talking about.”

Part of the surge in interest can be attributed to what Hitchcox calls the “large charismatic birds” like the ospreys and bald eagles. Once near extinction due to the widespread use of the now-banned insecticide DDT, which caused severe thinning of the large birds’ eggshells, sightings of those species are now commonplace as they hunt for fish along Maine’s coast and rivers.

Then there was the great black hawk that transfixed all of Maine last year after it wandered far north of its normal habitat and hung around at Deering Oaks in Portland before finally succumbing to frostbite.

The great black hawk’s demise prompted Friends of Deering Oaks to launch a $29,000 effort to memorialize the bird with a bronze statue. The hawk itself was preserved for eventual display at the Maine State Museum.

Yet, even as we cheer the resurrection of the eagles and ospreys and celebrate the life of a single wayward hawk, the more common species are vanishing before our very eyes.

“There’s still this funny disconnect,” Hitchcox said. “We’ve lost a lot of birds and we know it – the proof is right in front of us – but people are not aware of the extent of it.”

Nor are many people aware of how they’re contributing to it.

That beautiful lawn around your house?

However nice it may look, Hitchcox said, it’s hardly bird-friendly. The pesticides and herbicides many people use actually knock out the bottom of the food chain on which birds of many feathers rely. And while there are many native plants that can actually enhance the bird habitat around your home, lawn grass is not one of them.

“You’re not supporting any wildlife with it,” Hitchcox said. “You might as well pave your yard from the birds’ perspective.”

The coffee you drink?

If it was grown on a sunny plantation, where the trees and other vegetation were cleared for maximum yield and efficiency, it’s contributing to the loss of migratory bird habitat.

Hitchcox recommends “shade grown” coffee. It grows beneath the trees and thus preserves the winter homes of many birds that split their time between Maine and faraway southern climes. Better yet, Hitchcox said, it tastes better.

Are your house windows like mirrors? A screen here or a few pieces of hanging string there can help save a bird from a fatal collision.

Own a cat? It may be “Fluffy” to you, but out there in the yard it’s a cold-blooded killer. “If they see a bird, they’re going to kill it,” Hitchcox said. “And they’re really good at it.”

Finally, there’s climate change.

Warming temperatures in Maine, however insidious, already are making life difficult for some species.

Borealis chickadees, once ubiquitous along midcoast Maine, have retreated to the north and western mountains, Hitchcox said.

Bicknell’s thrush, which traditionally nests at elevations of 3,000 feet or higher, have nowhere to go as temperatures rise and other competing species, such as the Swainson’s thrush, move higher up the mountains.

Even Maine’s iconic loons may eventually find these parts too warm for their summer breeding season. And as the planet warms, Hitchcox noted, “there’s only so far north they can retreat.”

So, to those who heard last week’s news about our plummeting bird populations and shrugged, think again.

That barn swallow might eat a mosquito carrying eastern equine encephalitis (EEE) before the mosquito passes the disease onto you.

The same goes for the wild turkeys that gobble up every tick in sight at Gilsland Farm and thus all but eliminate the risk of Lyme disease there.

And the songs of the American goldfinch, the cardinal, the white-throated sparrow and all the others that transform a walk in the woods into a natural symphony?

If that’s your personal nirvana, let’s keep it that way.

And if you have no idea what I’m talking about, listen up.

Those birds might be trying to tell you something.