Sanje mangabey Cercocebus sanjei kills an African crowned eagle Stephanoaetus coronatus.

We present the first ever reported observations of a hunting African crowned eagle Stephanoaetus coronatus being killed by a primate, in the Udzungwa Mountains of south-central Tanzania. An adult female eagle launched an attack on a young Sanje mangabey Cercocebus sanjei who was feeding in a tree, but was intercepted and bitten by an adult mangabey who was feeding nearby. The adult mangabey and the eagle then fell together 25 m to the forest floor below. The eagle subsequently died from her injuries, while the mangabey escaped and is thought to have survived. This rare event is briefly discussed in the context of previous accounts of primate-crowned eagle interactions.