I suppose things are changing all the time, so I suspect now the people who actually live near the river **are** wary of them--probably the sign is for people who are visiting.

And, although I know now about hippos' reputation, I honestly didn't before coming across this story. Since I was ignorant, it's easy for me to imagine other people being ignorant.

Yeah, I worry about the manatees too. I'd like to know more about the two species' pattern of interaction--though they haven't been interacting for all that long. If they don't compete directly for food, and if the places they give birth in are different, then maybe they can share the same space? But if hippos are aggressive about other big guys coming into their space, then maybe things won't work out. And if Colombian zoologists are worried, I guess there's good reason to worry.