What was this guy doing, anyway? What was he looking at? Didn't he notice ANYTHING about his surroundings that would have tipped him off really soon that he had gone wrong? It took him HALF A DAY to realize he'd made a mistake?
And this guy is a WILDLIFE biologist.
I think that's your answer. He was doing what biologists do- looking at the biology, and not paying attention to his surroundings.