A scientist on his honeymoon recently filmed an exceptionally rare, grisly sight: an adult male leopard cannibalizing another a juvenile male leopard, mere minutes after the kill.

“It was a once-in-a-lifetime event to witness, for sure,” says Tanner Harvey, a Ph.D. student studying snake venom at the University of Northern Colorado.

His work often takes him into the field, but Harvey’s December trip to Tanzania’s Serengeti National Park was strictly personal.

Just after dawn on December 30, Harvey and his wife Kathy Yang embarked from their campsite with their guide, hoping to catch a glimpse of a nearby lion pride.

As their vehicle curved around a rock formation, the group saw a leopard panting at the foot of a tree,