With more than seven billion of us and counting, humans are the most prolific primate species on Earth.
This boon for man may be the undoing of apes, plus many other non-human primates like monkeys, tarsiers, lemurs and lorises. A recent study found that about two thirds of all non-human primate species are now threatened with extinction, and three quarters have declining populations.
Dr. Paul Garber co-led the study. He joins us with the grim news from the world's forests.