When the sun sets, the fun begins for beavers and nutria at Metro’s Smith and Bybee Wetlands Natural Area.
That’s when the animals get to work building dams. In one of the first images of its kind, night-vision cameras last fall captured photos of native beavers and invasive nutria working together to build a dam across a channel connecting Smith and Bybee lakes.
The beavers function as architects and engineers who use branches to construct the wooden bones of the dam. The nutria then use their cheeks to layer the dam with mud.
“This video is an opportunity for kids and adults to have a connection to these animals,” said Katy Weil, a scientist with Metro’s natural areas program. “They can see a hard night’s work in three minutes.”
Neighboring blue and green herons and mallard and teal ducks all watch the action unfold. Weil was particularly excited to see a rare black-crowned night heron.
“We know there are so many species using urban greenspaces, but we don’t often get to see them,” she said. “Seeing these photos made me really excited and hopeful.”
At nearly 2,000 acres, Smith and Bybee Wetlands Natural Area is one of the largest protected wetlands within an American city -- hiding in a part of Portland surrounded by port terminals, warehouses and other commercial developments. The wetlands are also home to river otters, black-tailed deer, osprey, bald eagles and Western painted turtles.