'Striking' footage captures the moment a red fox preys on a wolf pup — a behavior never seen on film before

A still from a night-vision camera in black and white showing a red fox scrambling backwards out of a wolf den holding a small dark wolf pup in its mouth. .

Striking first-of-its-kind footage has captured the moment a red fox preyed on a 1-month-old gray wolf pup at a nature reserve in Italy.

Scientists monitoring gray wolves (Canis lupus) in the Castelporziano Presidential Estate, a nature reserve about 15.5 miles (25 kilometers) from Rome, had noticed a female with a swollen abdomen. GPS monitors showed her repeatedly visiting a secondary den, suggesting she had already given birth.