Eight million people and one of the world’s highest densities of mountain lions live next door to each other. To keep track and better understand this top predator, the Santa Cruz Puma Project is and has collared dozens of mountain lions over the years. Through the data from the collars they have determined puma densities, kitten survival rates, habitat use, predator-prey relationships, and most importantly, how humans impact all of those factors. They have discovered that pumas are very afraid of people (even abandoning kills when they hear the sound of people - done through an audio/camera trap study on kills), they have to kill more often since they don’t feed on kills near human settlement as long as pumas in the pure wilderness, that they tend to stay away from settled areas, with dispersing sub-adults being the ones that sometimes venture into human neighborhoods. Despite all of these factors, these pumas have a lot of kittens, many of which make it to adulthood. The leading cause of mountain lion fatality in the area is intraspecific conflict, meaning lions killing each other, probably over territory.