No solid clues in mountain lion death in Santa Monica Mountains

The cause of the death of a young mountain lion found by hikers last month in the Santa Monica Mountains remains a mystery after inconclusive laboratory tests.

The necropsy did reveal the young female lion was exposed to rodenticides, although at low levels.

“Unfortunately, we’ll never know exactly why this animal died,” said Dr. Seth Riley, an expert on urban wildlife with the Santa Monica Mountains National Recreation Area. “Mountain lions in this region face a number of challenges to survive, and rodenticide exposure is certainly a common – and entirely preventable – health risk for local wildlife.”

Tests conducted by the California Animal Health and Food Safety Laboratory and UC Davis detected exposure to two anticoagulant compounds commonly found in rodent poison. Anticoagulants can cause uncontrolled bleeding and have been confirmed as the cause of death of two other mountain lions in the Santa Monica Mountains during the last decade.

Mountain lions may ingest poisons when they eat animals that have consumed them.

Park officials said the death of Puma-25, as the 1-year-old female was known, did not appear to be the result of a conflict with another lion. The animal was not emaciated and did not seem to suffer from a lack of nutrition, testing showed. Plague, which has been found in other mountain lion populations outside the state, was also ruled out as a possible cause of death.