The primary cause of the decline is due to a combination of traffic related mortality ( 3 from the area were killed within a matter of months , ) anti-coagulants ingested from human poisoned prey ( 2 individuals within the Simi Hills ) and attacks by other , more dominant mountain lions ( an elder male , known as P1 , killed both his son and his mate , this is though to be due to a lack of space available . ) The primary cause of the decline is due to a combination of traffic related mortality ( 3 from the area were killed within a matter of months , ) anti-coagulants ingested from human poisoned prey ( 2 individuals within the Simi Hills ) and attacks by other , more dominant mountain lions ( an elder male , known as P1 , killed both his son and his mate , this is thought to be due to a reduction in available habitat . )