The big cats are, first and foremost, predators. They do not have an "instinctive" fear of man. Before we moved to the top of the food chain the largest cats of Africa, especially the leopard, were the deadliest killers of our ancient ancestors. Fossil records indicate that the leopard killed ancient humans by seizing them from behind, pinning them to the ground, and then inserting their two upper fangs through the eye sockets and into the brain.
After our ancestors grew intelligent enough to develop weapons, the tables were turned. Our politically incorrect but immensely practical grandsires began to systematically eliminate every dangerous predator they possibly could. These same predators "learned" to fear man. This fear persisted until the latter part of the 20th century, when modern man developed conservational ethics, and began to rationalize away the latent threat that these ancient predators pose. Justification for this reasoning is usually based on statistics which purport to show that, because there have been very few attacks on humans by these animals in the 20th century, they have no natural inclination to attack us.
That is erroneous. There are two reasons these cats have seldom attacked humans in modern times. One, efforts to reduce the numbers of these predators during the 19th century were extremely effective. Two, the hunting of these animals, especially with dogs, has reinforced their "learned" fear of man. As a result, even when cougars have met people in the wild, they have avoided them.
Modern conservational ethics, grounded largely in faulty science, has drawn all the wrong conclusions from this. When California halted the hunting of cougars in the late 1980's I believe, the population of these cats began to rebound dramatically. As a result, a new generation of cats has been produced which, because of reduced danger and increased contact with humans, lost most of its fear of us. Naturally, attacks on humans, and killings, have become more common.
I do not like to see animals killed needlessly, but more and more of this type of thing is likely to occur. Urban Americans are going to have to come to grips with the fact that these cats are dangerous, and are likely to become more so if current attitudes do not change.
Regards, Shuckins