A Chilliwack, B.C., couple awoke to a bloodbath on their sheep farm last week, the work of a large male cougar with something to prove.

"I was so overwhelmed -- I just didn't know what had happened," Marlene Letkeman told CTV News. "They were lying around the whole compound and every one of them was dead. It was like going into a war zone -- bodies everywhere.

"And I ran to each one trying to see if any were alive, and none of them were. All had broken necks."

It's the second known attack on farm animals in three months, leading conservation officers to believe there's been a gradual increase in cougar numbers. In July, a cougar was shot after a pair of goats was attacked in Maple Ridge.

Marlene and Ron Letkeman found 11 of their sheep killed by what conservation officers believe was the work of a 150-pound, approximately five-year-old male cougar that was sending a turf-ownership message to his competition. Food was not his primary motive.

The cougar spared the life of a single sheep.

"Our whole herd was decimated except for Big Mama," Letkeman said of a sheep that had the wherewithal to run and hide behind a woodpile, which may have saved her.

A conservation officer expected the cougar to return to the farm the next day, and he was waiting for it. Environment Minister Barry Penner said the cougar was killed with a single shot.

"The cougar was very close to the residence when the conservation officer arrived," Penner said. "I'm told that this behaviour is not seen often, but it does occur, particularly for male cougars in their prime when they are trying to send a message to their competition.

"This cougar was so large and so strong, he could attack and potentially kill a black bear. So when it killed 11 sheep in one night there were concerns about public safety that this cougar seemed to be on a streak. He wasn't just killing for food."

Cougars may be increasing in numbers because of a population boom among deer, their primary food source.

"It appears in B.C. we have seen an increase in deer populations, so it's not surprising to see it in cougar populations as well," Penner said.

With a report from CTV British Columbia's Michele Brunoro