Turtles

Why don't you simply talk to them to see what's going on? Ask where they're taking them without giving them a leading question. Be a good neighbor.

I figured if they were poachers, they would have a good response ready for any nosey Gringo. And I didn't want to drag my wife out of bed. (she is the much better Spanish speaker)

After there was a bit more light, and I saw them again, I'm pretty sure it was one of the guys from Roberto's in Troncones.