(Ben Claassen III/For Express) (Ben Claassen III/For Express)

The sound an agitated whale might make is never far away in Washington. It’s the noise that’s made by Metro’s aging escalators. So when a reader contacted us to say there were weird bird chirps emanating from the Franconia-Springfield station, I figured the culprit was most likely a malfunctioning SmarTrip dispenser.

But I checked on the tip anyway, and was shocked by spokesman Dan Stessel’s response: “It apparently is a real thing.” Our fine feathered friends were creating such a nuisance at that station, he explained, that someone installed a device that plays the sounds of distressed birds and predators to encourage them to flap away.

I went to take a gander.

Exiting the Blue Line train, I found myself inside an anti-bird fortress. The roof of the station is lined with spikes — they shoot up from signs, beams, pillars. And right outside the faregates is the BirdXPeller Pro that Stessel had told me about. Only it wasn’t making any noise.

Jovial station manager J.C. Jackson agreed he couldn’t hear any of the bird sounds either. But that’s because he tunes it out, he said. And he guesses the birds probably do, too, which would explain why they still come flying at the windows on either side of the entrance. “See those splotches? You can see some wing and beak prints,” he pointed out.

Acting on Jackson’s theory that the device might be motion-activated, I threw my pen into the air in front of it. The technique did successfully result in a sound: the laugh of Justin Grayson, 23, who was getting cash from the station ATM.

When I mentioned the bird noises, however, he stopped looking at me like I was crazy. He’d heard them before, although he’d never actually seen the birds responsible for the commotion. These incidents always seemed to happen while he waited outside for the bus, he told me.

So I walked toward the exit, hoping to finally engage in some bird-listening. And then, “Chirp chirp chirp!” It was faint, but it got louder as I rode down the escalator toward the bus stop and parking lot. I hung a left at the women’s bathroom and trudged into a patch of uneven, muddy grass, which is where I found myself directly beneath a second BirdXPeller. This one was definitely switched on, and it was blasting scary noises that could have been the soundtrack of “The Birds 2: The Reflocking.”

A few feet away, people milling about didn’t seem to be paying any attention. But when I asked Jean Franklin, 57, about the racket, the woman could not have responded more emphatically. She’s been spooked by it before, especially the part of the looped recording that sounds like a deranged monkey playing a kazoo. If only she had the right shoes on, she would have trekked into the odd little sliver of nature that abuts the station to investigate where the noise was coming from.

“Other cities have trolls under their bridges. Some species we thought was extinct is living at Franconia-Springfield,” Franklin joked.

Since I wore sneakers, I decided to explore the way Franklin could not. I ventured into the bushes, where the only wildlife I managed to track down was a pair of mockingbirds.

They were, of course, completely silent.