John you commented:
"Btw some of these modern "maneaters" seem to be quite young cats". I have made the same observation for cougars and Jaguar that predate on livestock and in one case on a human.

More or less 50 years ago I spent several years working in the jungle covered Mosquitia region of Honduras and Nicaragua. My assistants and I lived in the primitive villages widely scattered along the streams draining the region and to a large degree subsisted off the local economy. Living in constant contact with the local inhabitants it soon became clear that Jaguar depredation on cattle, swine and other livestock was an ongoing issue for the campesinos. When the majority of your wealth is concentrated in a cow and her calf or a sow and her piglets any loss is heart breaking or debilitating. I took an interest in this situation and tried to visit as many kill sites as were brought to my attention. I had the impression over time that the animals visiting the vicinity of the villages on average left smaller foot prints than those prints I observed on sandbars along the streams. At the time I rationalized that sub-adults might 1) be attracted to the semi-domestic biomass that was less predator evasive than the natural prey species farther from the villages and 2) had not yet fully developed fear of humans.

Fifty years on in life I am in a position where I have the duty to inspect many if not most of the cougars the Conservation Officer Service harvests in southwestern British Columbia. These are harvested due to conflict with humans or perceived danger to humans. Once again I am observing that the sub-adult age class is substantially over represented in the cougars harvested due to human/cougar conflict ie guilty of having lamb, cabrito or other livestock on their breath, hanging out in the hedge at a local school or in one case a predatory human attack. The old, weak and injured do not appear to be the cougars predating on livestock. I think the over representation of the sub-adult age class is due to these being the equivalent of teenagers making bad decisions as they gain life experience, but before they learn to be particularly afraid of humans. Looking at the photographs in this thread it would appear that sub-adult leopards living in close association with humans have plenty of opportunity to make similar bad decisions.