Washington, Aug 16 (IANS/EFE): Mountain lions found near Los Angeles' Santa Monica mountains are completely isolated from other populations of their species by the barrier of urbanised areas and a freeway to the north.

The mountain lions of Santa Monica are a rare example of the large carnivore persisting within the limits of a megacity.

Over the past decade, only one young male from outside the area managed to enter the habitat of the mountain lions of Santa Monica, while none of those living there ever left the area, according to a study led by Seth Riley of the US National Park Service.

"Large carnivores can be particularly sensitive to the effects of habitat fragmentation on genetic diversity," the authors said.

Due to their almost complete isolation, the Santa Monica mountain lions exhibit dangerously low levels of genetic diversity, and the sole male that entered the area from the outside in 2009 "successfully mated, and substantially enhanced genetic diversity" among the entire population.

Among the types of behaviour characteristic of isolation, researchers found many cases of "father-daughter inbreeding", and mountain lions killing their cubs, mates, siblings and others of their species.

Such behaviour, scientists say, is unusual and never occurs if sufficient movement and contact among different populations is possible.

Riley said that for the long-term survival of Santa Monica's mountain lions, it is vital to establish ways of connecting them with other populations of their feline species.