Kuger, I read it as "ON" the dumpster, not in the dumpster. Maybe it jumped up there to get a better view, (for high ground).
Maybe those lions there in CA. are not afraid of humans, beacuse they are not harvested. It kind of like the Grizzly bears that wander outside Yellowstone and Glacier. When the bears hear gun shots, they will seek out and pinpoint from where the shot came from, looking for that free meal. I have heard many instances where hunters have been force away by the grizzlies. They have no fear of humans!