Predator-proofing at an Audubon Sanctuary

I visited a local Audubon sanctuary looking for Cedar Waxwings. No luck, but it's a very nice location just 10 miles away from the house. It's an old farm of 129 diverse acres that contains meadows, streams, wetlands, and woods.

The nest boxes are heavily fortified with a gauntlet of anti-predator devices ranging from pole cans, pole cones, and deep plastic entry tubes to thwart raccoons and opossums, to grape netting to thwart and trap climbing snakes.