The Hamilton biologist says the discovery during his night-time walk in the woods at the Eramosa Karst Conservation Area was doubly unusual because owls generally only fly down to this area from the north during the winter.

But the karst’s thicket of hawthorn trees and surrounding fields are ideally suited to owls, he said, offering both cover and a likely abundance of food like mice and voles.

The pair gave birth to two owlets – captured on camera by Stoney Creek resident Faye Baker before they left their nest –the first confirmed breeding record since 1968 in a 40-kilometre radius that includes Hamilton and parts of Mississauga, Brantford, Clinton and Cayuga, he said.

“It’s at least possible that they’ve been breeding here all along,” said Mr. Minor, who managed to take photos of the adult owls on a return visit with a bird expert.

“What’s changed is, with the trail systems put in here, crazy people like me walk around at night and see them,” he said. “During the summer in the Hamilton area they’re very rare.”

But Mr. Minor cautions visitors hoping to spot the owls to stay on the trails because startling them could have deadly consequences for the birds.

“The key is to not look at them for very long because if you make them nervous and they fly during the day, red-tailed hawks that we also know nest in here will catch them and kill them,” he said.

Mr. Minor said the owls’ presence and his as-yet-unconfirmed sighting of an atrisk eastern milksnake on a karst trail bolster arguments in favour of expanding the park.

The Ontario Realty Corp. is in the midst of an environmental study on its plans to convert 32 hectares of provincial land to the immediate east to housing – fields he said are not only crucial to the karst’s water flows, but also home to voles and mice and suited to milksnakes.

The area also has endangered butternut trees and atrisk monarch butterflies and chimney swifts, a small black bird that feasts on insects and is slightly bigger than a hummingbird, he said.

“I think the geologic features certainly warrant the protection they’ve been given,” Mr. Minor said of the 73-hectare karst park, a rare concentration of caves, sink holes, dry valleys and sinking streams.

“We have the opportunity to make it about 80 acres bigger, which is about 40 per cent bigger and that would probably improve the water reaching the karst caves, but from my perspective as a biologist it’s absolutely huge,” he said

“As this area’s cut off by encroaching urban sprawl, the number of species that will survive in the park increases greatly with the size of the park and 40 per cent is a big difference.”

To celebrate the discovery, the Friends of the Eramosa Karst, a group dedicated to expanding the protected area, is holding a name-the-owls contest at www.friendsoferamosakarst.org .

Spokesperson Rita Giulietti said she hopes the owls will boost support for the karst and efforts to preserve the ORC land to the east.

“These animals need open space and wooded space. They can’t just make do with small patches of land,” she said. “They need them to be together and those 80 acres are beautiful open spaces where they can hunt for all the voles and mice that they want and then take their shelter in the wooded space.

“It’s a perfect opportunity to encourage those animals to stick around and make it a home. And who knows? We could end up with a few more nesting pairs.”