Traveling from Detroit to Point Pelee Park in Ontario, Canada with a trunk full of photo gear. Hope to get some shots of birds and Monarch butterflies.
How likely will there be a problem either getting into Canada or returning to the US with my gear? Anything special I need to do to avoid being charged duty?
Stop at US Customs on your way out of the US and register your gear; won't be any problem bringing back in. Shouldn't have any trouble with Canada Customs if you are legit.
One of Chase's videos talks about travelling internationally with professional equipment, and the required documentation, called a ATA Carnet (www.atacarnet.com). Check his "equipment packing" video, it's at the end.
Fish (Steven Frischling) might have something on his blog about it, too.
He hangs out here occasionally, so he might even stop by. Paging Fish....