The mountain lion’s predatory instincts kicked in, Arizona Game and Fish Department officials said.
That’s why it didn’t stop until all 20 emus were dead on the ranch south of Queen Creek.
Marty Fabritz, East Valley field supervisor for the department, said Friday the mauling deaths of the emus in their pens before dawn Wednesday isn’t shocking behavior for a mountain lion.
"That doesn’t happen a lot," he said. "But it can. They are predators. That was just predatory behavior that kicked in."
The lion’s prey wasn’t small: Emus are flightless birds that resemble ostriches, can weigh more than 150 pounds and stand 5 to 6 feet tall.
Joe Carreiro, a resident of the area near the San Tan Mountains, owned the birds. He reported their deaths to the department on Wednesday, and Game and Fish confirmed it was the work of a mountain lion.
The lion’s presence isn’t unusual because the ranch is near San Tan Mountain Regional Park, Fabritz said.
"That is suitable lion habitat; it’s desert," he said. "It’s just on the fringe of town where we’ve got a bunch of people and where those animals provided an opportunity for that lion."
Carreiro told the department that he saw the lion and it looked to be about 145 pounds, which would mean it’s a large male, Fabritz said. Game and Fish officials haven’t spotted the lion yet. An official passed out literature on lions to neighborhoods in the area earlier this week.
Fabritz said people who live in areas where mountain lions have been sighted often worry about the safety of their children. To keep children safe, residents should watch them when they’re outside and wait with them at the school bus stop, he said.
The department plans to only monitor the lion for now because it hasn’t displayed unprovoked aggression toward people and the attack wasn’t part of a pattern of repeated nuisance behavior, Fabritz said.
"It has displayed aggressive behavior only with something it was going to eat," he said. "Typically, what they’ll do is they’ll make a kill, and they’ll eat, and then they’ll come back later for more until the food is gone."
Spotting a lion
If you see a mountain lion in your neighborhood, report the sighting to Arizona Game & Fish at (602) 942-3000 from 8 a.m. to 5 p.m. weekdays. To report a sighting immediately after-hours or during the weekend, call the Operation Game Thief hotline at (800) 352-0700.