A friend taking part in an owl survey a few years ago thought she’d heard a barn owl screaming in the woods. At least, she hoped it was a barn owl, because otherwise all she could think is that someone was being murdered. If you’ve heard a barn owl shriek (described on the Stokes bird song CD as “human-like scream”), you’ll get some sense of her concern. The sound will make the hairs stand up on the back of your neck. I bet there’s a notable statistic from the barn owl’s breeding range of 911 calls made by people who thought someone was being tortured in a barn when really it was just a sociable barn owl. But barn owls aren’t found in Maine, so her report was puzzling (if also a bit disquieting).

I was recently reminded of this unsolved mystery when a poster on the Maine birding list-serv this fall, knowing she probably hadn’t heard a barn owl, asked what else screams in the night. Curiosity piqued, I decided to do a little research. Like many people, I’d been told growing up that fishers scream. This was easy for me to believe, as it added to the creepiness of an animal that was invariably described as vicious, bloodthirsty, and probably responsible for any missing cats in the neighborhood. (This was before coyotes had become such a big presence in Midcoast Maine.) So I started with the (unfairly maligned) fisher.

A YouTube search for “animals screams night” brings up several videos labeled “fisher screaming.” The sound recorded is usually a series of short, rasping, drawn-out screaming barks. But in not one of the videos can you see the animal making the noise, which actually made me think of a fox’s bark. Fortunately, a search for “fox screams” pulls up some visuals, including one video in which a fox makes the “fisher” noise right in front of the camera in broad daylight. But I still had some doubts about whether a fox (or possibly a fisher) was what either birder had heard screaming in the woods. Even with the fox in full view in the video, the scream is unsettling, but it’s not a full-out scary shriek like that of a barn owl.

I consulted with Ron Joseph, a wildlife biologist friend, about fishers and foxes screaming. Ron also had his doubts.

As he reminded me: “Mammals are by and large silent outside of the breeding season. Neither fox nor fisher breed in the fall. Foxes breed in January and February and they make a high-pitched barking sound, not a screaming sound. Fishers breed in March, and I’ve never heard one scream. I’m not saying I know all their vocalizations, but I’ve just never heard one scream…. The only other screaming animal that I know of this time of year is porcupine.”

Screaming porcupines? Now there’s a terrifying image.

He directed me to an article that appeared in the New York Times this past February, “The Silence of the Fishers,” which specifically addresses the widespread belief that fishers scream. The writer, Roland Kays, is curator of mammals at the New York State Museum, where he studies fishers in urban versus wild settings. In the process of researching mammal sounds for a wildlife app, he noted that he couldn’t find anything resembling a fisher scream in any of the natural sound libraries he consulted. And he, too, thought that the YouTube video screams attributed to a fisher sounded like those of a fox.

Kays asked the country’s foremost fisher expert, Dr. Roger Powell, what he knew about fisher sounds. Other than “little agitated chuckles,” which Dr. Powell described as a fisher’s “typical vocalization,” the only other sound he’d ever heard out of a fisher in his many years of studying them was a “growl-like vocalization, and that was right as the fisher bit my nose (long story — luckily, I still have a nose).”

Also, Kays notes, most predators, except for social ones like coyotes and wolves that call to each other over long distances, are usually silent types, the better for sneaking up on their prey. Many carnivores, especially mustelids like fishers with well-developed musk glands, communicate by scent. “But,” he concludes, “an absence of evidence is not evidence of absence.” Someone may still come up with a conclusive YouTube video showing a fisher in mid-scream; until then, the jury’s still out.

As far as terrifying wildlife screams on fall nights go, however, Ron did come up with the probable answer. This fall, while up at his family’s camp in the woods of western Maine, he too heard “a blood-curdling scream” in the night. He jumped out of bed and ran out to the deck. “I listened to the scream several times,” he said. “It turned out to be a barred owl, right above me in a pine.” He added, “Most people don’t realize (or don’t want to accept—they’re hoping for a more exotic animal) that barred owls will actually scream without once hooting.” I’m also guessing that most people hearing shrieks in the dark woods don’t go running toward whatever is making that chilling noise. It’s far easier on the nerves to just make a video in the dark and call it a fisher.