But the near-universal uproar belies a much older reality. For most of history, humans have obsessed over lions, measured themselves against the big cats and — more often than not — sought to butcher them.
There is perhaps no animal on Earth that has generated more veneration and fear over the centuries. In myriad ancient cultures, lions were demigods and guardian spirits, symbols of nobility and righteousness.
From the Mediterranean to East Asia, statues of lions graced the gates of cities, the entrances of temples and the abodes of kings. The Bible is littered with passages gesturing to the awesome power of these "bold" and "roaring" creatures. A lion's body forms the foundation of ancient Egypt's most famous single structure.
To this day, the image of the lion bears real symbolism for dozens of countries. It's an icon for both the Cameroonian soccer team and Iranian dissidents in exile. It's the national emblem of the Indian republic, the dominant ensign in the flag of Sri Lanka and the logo of Thailand's most popular brand of beer.
But that never has stopped humans from killing lions. According to National Geographic, "2,000 years ago more than a million lions roamed the Earth." Now that figure may be as low as 20,000, with the majority left in Africa and a smaller number in India. The decline is largely the result of the animals' loss of habitat, encroached upon by a booming human population.
The lion hunt is one of the world's oldest tropes: Generations of political rulers drew legitimacy from images depicting their mastery or triumph over lions, among nature's most fearsome beasts. Friezes of lion hunts adorned the palaces of Assyrian kings, while the hunt was a constant artistic theme in courts in India and lands farther west.
But, according to National Geographic's calculations, the real slaughter of lions occurred only in the past two centuries. In 1800, estimates of the overall population were about what they had been for most of history — 1 million or so. But the decades thereafter saw a pronounced decline. By the 1940s, there were only 450,000, and a shocking 50,000 a half-century later.
This is the consequence of poaching as well as the effect of growing human populations and the parallel shrinking of the lions' habitat. In the 19th century, pith-helmeted British colonials embarked on the first great African safaris, slaughtering tens of thousands of the subjugated continent's exotic wildlife, including countless lions.
And he is far from alone. As a post in Wonkblog shows, trophy-hunting American tourists kill hundreds of lions each year, mostly legally. Palmer's hunt may be uniquely awful because Cecil the lion belonged to a protected habitat, but there's nothing unique about this act of killing.