Western gorillas are notoriously difficult to study. They live among dense rainforest, and habituating them to humans can take five years, says Robin Morrison, an anthropologist with the Dian Fossey Gorilla Fund.
“I can count the number of habituated [western gorilla] groups in the world on one hand,” she says. So to get a close look at how they interact with one another, Morrison and her team used some inconspicuous surrogates for human eyes: high-definition cameras.