The society uses the mesh to protect large trees near Lost Lagoon, so they won't be gnawed down by the busy pair of beavers that live there.
"The idea is there's no way that a beaver, as industrious as they are, would be able to take that [wire mesh] down," said Brian Titaro, conservation technician with the Stanley Park Ecology Society.
But some human appears to be trying to help out the beavers, said Titaro.
The ecology society is regularly finding the wire tree-protectors — which are installed using pliers — removed and dumped in the water, where other wildlife can get stuck in the mesh.
"My suspicion is it's probably … someone whose heart is in the right place and maybe just doesn't understand our program," he said.
Beavers taking down habitat for other animals
Small, fast-growing trees are left wire-free by the conservation group, so the beavers can still get food and lodge-building materials, said Titaro.
The wire mesh is only put on mature, older trees, which stabilize the banks of the lagoon and nearby Ceperley Creek.
"These trees are really important habitat for birds and other species," said Robyn Worcester, conservation program manager with the ecology society.
"The beaver is important, but lots of species rely on the wetland, not just the beaver."
They suspect the beaver "helper" is acting late at night.
"Hopefully, we'll eventually be able to run into them doing this, and we can educate them on it, and work together to help the beavers."
MAP: Lost Lagoon in Stanley Park, VancouverSuggest a correction