Raymond Perry can replicate the sound of an owl.

In fact, he can replicate the sound of all three species of owls that visitors to Five Rivers might be likely to hear. Beyond that, he can make a variety of noises that the owls would make in different situations.

Take, for example, the eastern screech owl. Perry makes a whining noise, and then a very different-sounding descending tremolo.

What about the screech? He can do that, too. Although you won’t hear a screech this time of year, he said.

Why? Because the screech of the eastern screech owl is made only by young owls, if they are agitated. Perhaps, they are hungry; then they would screech to their parents for food.

Or perhaps they are feeling threatened by a predator. They would screech to get their parents’ attention, for protection.

But, there are no young owls this time of year. Now, adult owls are trying to establish their territories and are searching for their mates.

Perry, in years’ past, has led the group of volunteers who come to the Five Rivers Environmental Education Center at 46 Game Farm Road in Bethlehem for the annual owl count. This year’s count, with center staff and experts from the Audubon Society of the Capital Region, will be held on Saturday, Dec. 6, starting at 4 p.m. The event is popular and already filled, but a waiting list is kept, said Perry; to add your name to the list, call 475-0291.

How do you count owls in the dark of night? “You search for owls mainly by listening,” said Perry.

At 60, Perry has been listening to bird calls for decades. He’s been an environmental educator with State Parks and the Department of Environmental Conservation for 30 years. Formerly the director of the bird conservation program for State Parks, Perry is now back at Five Rivers.

“In the old days,” he said, “you might have a cassette tape” of recorded owl calls, which could be played in the field to elicit a response. “Now you scroll to an app.”

“Owls aren’t very critical,” said Perry; they will respond to human imitations of their calls.

But observers should be careful not to overdo; that would interfere with their mating.

Perry demonstrates the call of an owl: “He’s saying, ‘Here I am. I’m looking for someone.’” Then a female may respond to the male call.

Birds have calls as diverse as human speech, said Perry. “Sometimes, people say, ‘What’s that bird? I thought they sounded like such and such.’ I can’t tell you, ‘This is what a person sounds like.’ People speak different languages and have different tones,” said Perry. The same person can make one sound while screaming in pain, and another very different sound while cooing to a baby.

“It’s not like a children’s book where the cow says ‘moo,’” he said of bird calls.

Five Rivers visitors are likely to see, or at least hear, three species of owls. In addition to the eastern screech owl, Five Rivers is home to great horned owls, which have a deep hoot. “Most owls don’t hoot,” said Perry. The third species, the barred owl, named for its streaks, is one familiar to five Rivers visitors, Perry said, because for years, the center had one.

“After the walk,” said Perry, “everybody convenes at the picnic shelter with a fire pit.”

There, dedicated volunteers have been preparing hot dogs and hot drinks for the owl counters to enjoy as they compare findings. Some years, Perry said, the owlers have hunted in vain only to return to the campfire and discover the hot-dog preparers have heard many owls.

“It’s a part of nature you don’t get to experience all that often,” he said of listening to owls at night.