The El Paso Zoo was forced to shut down Friday when an employee spotted an uninvited addition to the zoo's collection of wildcats.

The mountain lion easily could have jumped the zoo's 8-foot fence but probably moved on to avoid the noisy search party, director Steve Marshall told the El Paso Times.

A security guard heard the cat growling in the outdoor part of the elephant exhibit about 6 a.m., but it ran away when the guard shone a flashlight at it, according to the Times.

Zoo administrators closed the park for the day as crews, including zoo staff, Texas Parks and Wildlife workers and El Paso police, kept resident animals in their indoor shelters and searched for the prowler.