By Will Broaddus
---- — Owls do more than just hoot.
“The screech owl makes a whinny or tremolo,” said Angela Walsh, a field teacher at the Ipswich River Wildlife Sanctuary. “All owls have a lot of different sounds, like bill-clicking noises when they’re annoyed.”
Visitors will get a chance to practice owl calls tomorrow night at an “Owl Prowl for Families” at the sanctuary, a Mass Audubon property in Topsfield.
“With the barred owl, we put a mnemonic to it: ‘Who cooks for you, who cooks for you all?’ That’s the hooting,” Walsh said. “Then the great horned owl does: ‘Who’s awake? Me too.’ The kids like it, and it’s easy for them to remember.”
The event will begin with a slide show and discussion of the 11 owl species that nest in this part of the state.
“The kids get involved,” Walsh said. “We let them listen to ‘Owl Moon’ on tape, a book about a child owling with their grandfather. Then, Scott and I will divide them up, and we’ll each start calling on our own side.”
A group led by naturalist Scott Santino will head toward the boulders and bushes of the rockery, which rises next to a pond, while Walsh will lead a second group in the opposite direction, toward a canoe landing on the Ipswich River.
“We’ll try different owl calls, then meet at the end and let the kids practice owl calls at the top of the hill,” Walsh said.
Ornithologists believe that owl calls are related to both territory and mating, Santino said.
“They want to have a nesting area, an area to forage for food with as little competition as possible,” he said. “Vocalization is to claim your territory.”
It also helps to attract a mate, which owls do earlier in the season than other bird species.
“One reason we do the Owl Prowl in winter, as we come into late February and March, is you’ll have a higher likelihood of hearing the birds, because this is when they get started,” Santino said. “Owls are first to find a mate.”
Owls that typically nest on the property include barred, great horned and eastern screech owls, while long-eared and saw-whet owls may be visiting.
“Saw-whet owls — like whetting a saw, that’s the sound they make — they’re more northern, they migrate through,” Walsh said. “We do call for them. The saw-whets like a whistle.”
The Owl Prowl is held at night because that is when the three main species are most active, although, they will appear during the day.
“I would say the barred owl, of the three, is most likely to be encountered during daylight hours,” Santino said.
Walsh and Santino don’t expect to see any of the snowy owls that have appeared locally in record numbers this winter, because that species prefers the tundra-like habitat at sites like Plum Island, while the sanctuary features woodlands and wetlands.
Walsh recently practiced calling barred owls while leading a group on a maple-sugaring tour and was happy to hear them call back.
Although the birds don’t always answer during owl prowls, they are still sometimes curious enough to want to see who’s making their sound.
“They’ll fly in, and we put a red spotlight on them,” she said. “It’s less obtrusive.” Owl eyes have few cone cells, which detect color difference, and therefore aren’t bothered by red-tinted light, Walsh said.
They have special features that help them hunt, including heads that can swivel in a 270 degree arc, letting them remain still while looking for prey. Many species also have asymmetrical ears, with one pointing up and the other down, which helps them pinpoint the source of a sound.
“They do glide in once they home in on prey,” Walsh said. “Their feathers are designed to be quiet when they fly.”
The great horned owl is the biggest species that visits the sanctuary, while the saw-whet is the smallest. The creatures they hunt correspond to their size, Walsh said. But this time of year, owls are commonly eating meadow voles and white-footed mice on the property’s 2,000 acres.
“Great horned owls will consume skunks,” she said. “They have a terrible sense of smell.”
IF YOU GO
What: “Owl Prowl for Families”
When: Friday, March 13, 7 to 9 p.m.
Where: Ipswich River Wildlife Sanctuary, 87 Perkins Row, Topsfield
Cost: Members, $8 adult, $7 child; nonmembers, $10 adult, $8 child. Open to families with children ages 5 and up.
Information: Dress warmly. Meet in the barn. Preregistration required at 978-887-9264 or www.massaudubon.org/ipswichriver.