Sutu Forte, a nature activist in Columbia, Mo., conducted a tree sit for eight days in protest of a new trail that would destroy a wildlife sanctuary her organization, It's Our Wild Nature, swore to protect. The city began construction on Monday and peacefully removed Forte from the tree on Tuesday.

He sits at a booth draped in colorful anti-war posters, usually talking to curious students taken aback by his boldly pacifist stance. On his table lies a variety of cartoons highlighting the moral, financial...