Upon arrival in Hobart, Tasmania's tidy, bustling harbor city, it took me a few minutes to put the lie to the story that more than a few Australians had told me. I looked and looked, but there were no two-headed people walking about.

Mainland Australians make jokes about their island neighbors in the same fashion as mainland Canadians do about people from Newfoundland and the English about the Irish. Sociologists say that mainlanders project their dreams and fears on close-by islands; the islanders are both envied and taunted. The joke Australians love to tell about inbred Tasmanians with two heads is a wink and a gibe at its apartness.

That separation -- the island lies across a couple hundred miles of notoriously turbulent sea from the southern coast of the mainland -- is a defining tenet of both Tasmania's human history as well as its natural history. I had come to explore both, the remains of a well-preserved penal colony where England once sent its criminals and the iconic and now endangered animal found nowhere else, the Tasmanian devil.

My base was Hobart, Tasmania's lone outpost of cosmopolitanism tucked between the busy harbor on the east and the often snow-dusted Mount Wellington on the west.

After a long morning walk through Hobart's parks, I relaxed at a sunny sidewalk cafe in the trendy Salamanca district. Over a pint of Fosters, I reflected on the feel of the place, its mild climate, rich history, verdant parks and rare wildlife. Clearly, there is far more to envy than to make fun of about Australia's southernmost state.

Penal colony turned museum

Dutch navigator Abel Tasman was the first European to spot Tasmania, which he named Van Diemen's Land, in 1642. But it was the English who colonized the place.

In early 19th-century England, an acute shortage of good paying jobs and few social welfare programs forced many working-class people to make a choice between starving and stealing. Most chose stealing. Crime rates soared.

In response, Parliament passed the "Black Laws," making more than 200 crimes punishable by death. As most English juries didn't have the stomach to hang a man for stealing fruit from a neighbor's tree, they would instead find the accused guilty of something a bit less serious, punishable by "transportation," a one-way ticket to Australia, often its island state of Tasmania. Soon, ships were regularly sailing to the other side of the world, filled with convicts unlikely to ever see England again.

A few tree-lined blocks from Hobart's main harbor is the small, excellent Tasmanian Museum and Art Gallery, whose collection includes an extensive display of items relating to the island's convict period. Artifacts, such as an impressively large collection of leg shackles and cat-o-nines, show that discipline was rigorously enforced.

About 60 miles southeast of Hobart, a peninsula of land dangles like an appendix into the Pacific from the southeast coast of Tasmania. This physical partition from the rest of the island made it a perfect prison site, and its main town, Port Arthur, grew into one of the world's most notorious penal colonies.

Now Port Arthur is Tasmania's top tourist attraction, luring visitors in the same ways that Northern California's Alcatraz Island does. Designated a World Heritage Site in 2010, the place includes a number of well constructed sandstone buildings that have been faithfully restored, as well as a museum that provides insight into the state's convict period. Beginning in 1833, thousands of English, Irish and Scottish prisoners were sent to the Port Arthur prison. Surrounded by hungry dogs, armed guards and waters made unswimmable by riptides, currents and sharks, Port Arthur was billed as unescapable. Mostly, it was.

One ingenious prisoner tried to escape dressed in kangaroo skins. At dusk one evening, he started hopping through the surf out of range of the guard dogs. He had nearly reached freedom when he heard one of the armed guards shout to another, "Look at that old jack [kangaroo]. Why not have a shot at him?" To the guards' great surprise, the kangaroo suddenly shouted, "Don't shoot! It's me!"

Tasmanian devil under threat

Besides being an excellent location for sequestering tough cases from better society, Tasmania's isolation allowed the development of unique plant and animal life. The island's huge, temperate forests are home to a great number of strange beasts with peculiar names, including bettongs, quolls, pademelons and bandicoots, as well as dozens of avian and amphibian varieties found nowhere else.

Unfortunately, these creatures are not isolated from threats to their existence. Greg Irons is a 27-year-old Tasmanian wildlife expert. Like the late, great Steve Irwin, Irons has made it his mission to help his country's increasingly endangered animals. As general manager of the Bonorong Wildlife Park in southern Tasmania, Irons helps dozens of animals that have been injured, orphaned or otherwise compromised.

Bonorong Park is a short drive up from Hobart, beyond landmark Mount Wellington, past Hobart's northern suburbs and across a bridge spanning the wide Derwent River. After a few words of instruction on interacting with the animals, I walked into the park grounds to make some new animal acquaintances. It's even easier done than said. The kangaroos, with their huge, soft brown eyes, love having their chests rubbed after feeding, much as dogs like having their bellies rubbed. I let a big "jack" eat a handful of kangaroo chow from my hand, and a friendship was born. The emus will peck food from your hand, and the park's rangers allow visitors the thrill of rubbing a sleepy koala's wooly back. Other animals -- the bitey ones such as quolls and wombats -- are designated "no touch," although you can get close.

The undisputed king of Tasmanian fauna is the unfortunately but aptly named Tasmanian devil. During the few minutes each day when they're not ripping apart carrion or using anal scent glands to mark territory, they are actually fairly cute weasel-like critters. They run around playfully, then plop down to bask and snooze in the sun. They seem to love showing off their strong white teeth, opening their mouths in huge, wide smiles.

But they are no one's idea of a pet. They seem naturally ill-tempered, they have a propensity to bite and they screech a lot. When a couple of devils got into a fight over a hunk of wallaby meat, I was forced to cover my ears. Black with a white stripe on their chests, these 20-pound creatures lope along in a strange, shuffling gait reminiscent of a lame, geriatric cocker spaniel. In the real life version it's hard to see much, if any, of Taz, the spinning, grunting Warner Brothers cartoon character.

Despite the devil's orneriness and bellicose nature, Irons, and indeed the rest of Tasmania, is very concerned about the future of the strange little creature they call Tassie. The beast defines this place to the rest of the world. It sounds unimaginable, but the world's largest marsupial carnivore could soon disappear.

Seventy-five years ago, devils were merely the world's second-largest marsupial carnivore. The island was once home to the thylacine, otherwise known as the Tasmanian Tiger. The size of a greyhound, the thylacine was hunted and poisoned to extinction by farmers and herders. Back in the Tasmanian Museum and Art Gallery in Hobart, I had watched with growing despair a grainy black-and-white movie of the world's last thylacine, pacing the floor of its cage in the Hobart Zoo in 1936.

Like the Tasmanian Tigers of the 1930s, Tassie is critically endangered. A recently identified condition called Devil Facial Tumor Disease (DFTD) threatens to wipe them off the face of the Earth.

DFTD is a rare type of plague, a cancer transmitted from one animal to another during communal feeding. Invariably fatal, the disease has reduced populations by 90 percent in parts of Tasmania. Pity the poor devils, because in humans, and nearly every other animal on the planet, cancer cells themselves are not infectious. Because the Tasmanian devils live and breed only on a relatively small island, they are extraordinarily similar to one another genetically. This causes health problems of several sorts, and it is the primary reason that a contagious cancer could take hold.

But Irons is hopeful the species can survive, and he lists several efforts underway to help the creatures. "Research into a cure is important and ongoing," he told me. "But beyond that, we are installing insurance populations [colonies of disease-free creatures] on the Australian mainland and in fence-protected locations in Tasmania. And education efforts in Tasmania to remove roadkill [devils are often run over as they scavenge dead animals on roads], restrain dogs and save orphan devils are having a positive effect."

It's the latest instance of Tasmania's isolation being both beneficial and bedeviling.

"If we do everything we possibly can," says Irons, "I think Tassie will survive."

Minneapolis-based William Gurstelle has written for magazines such as Wired and the Atlantic Monthly and blogs at www.williamgurstelle.com.