Our backyard ecosystem has undergone a change, and I suspect it’s our fault.

For years, my wife and I have been backyard birdwatchers. At a late breakfast on the weekend or lunch during the week, we’d be dazzled by the volume of activity just on the other side of the kitchen window.

Our unofficial bird count is substantial to say the least: A handful of different types of sparrows, at least as many different types of finches, blue jays, cardinals, juncos, three or more types of woodpeckers, kinglets, grosbeaks, wrens, nuthatches, chickadees, robins, mourning doves, screech owls and more. And that’s just off the top of my head.

So over the years, we’ve added feeders. And added feeders. And added feeders.

Two or three have sunflower seed. One has thistle seed for the finches. One has a songbird mix. And another three or four have suet this time of year.

So on a typical lunch hour, we’d see clouds of birds swoop back and forth from feeder to bush, from feeder to our neighbor’s hedge.

The feeders also attracted squirrels, because the birds can be messy when they’re chowing down. It wasn’t uncommon to see five or six at a time.

Until a few weeks ago.

“I think we have a hawk,” said my wife.

She pointed at a shape high in the branches of a towering oak tree in a neighbor’s backyard.

“I think we have a hawk,” she repeated.

I thought so too.

And the evidence on the ground also pointed in that direction.

A feeder that usually requires re-filling once a week was still half full when I checked it. One that holds an enormous amount of sunflower seeds was nearly as full as it had been on Christmas Eve.

The clouds of birds had taken shelter elsewhere.

The squirrels became sparser as well. At times, the backyard was squirrel-free. Instead of half a dozen, a typical day in early January saw two or three squirrels at the most.

On New Year’s Eve, our hawk paid a closer visit.

As that nasty, cold rain came down the last day of the year, our hawk perched in a redbud tree close to the house for a good chunk of the evening.

Most of the time, it’s out of sight. But we know the hawk is there.

The birds and squirrels know it too.

So the feeders are full now for weeks at a time, and the view of our backyard ecosystem is far less engaging than it used to be.

It’s our fault, of course. We set out to attract birds. It never occurred to us to post a “No Hawks Allowed” sign.

As if that would have worked.