This is easily the hardest shoot I've ever done. It took five hours of a ridiculously tough hike into the steepest and densest rain forest environment in southwest Uganda to get the shot. We were allowed to spend only one hour with the gorillas, then a three mile hike out of the jungle. Worth every second, but I'm not sure I'd do it again. I was wishing I'd done this 30 years ago. :-)
Nikon D300, Sigma 70-200 2.8 OS, shot at 150mm, f/4.5, 1/40s, ISO 400