Things are looking bad for primate species around the world. We hear periodically about particular species struggling to make it amidst habitat destruction, hunting, and other challenges. But a new study has looked at the problem from an unprecedented vantage point, The New York Times reports. The study, published in Science Advances, evaluated the survival of all 505 primate species known to exist (some were discovered along the way), and the results were not good: About 75% are in decline and about 60% are facing extinction. Human activity may have already caused some species to die out and, without changes to help the primates come back, researchers fear more will follow.