In the mid-1960s a small group of Cuban iguanas was released from a zoo on Isla Magueyes, southwest of Puerto Rico, forming an independent free-ranging feral population.

There are now almost as many tigers living on rich people's ranches in Texas (some 2,000) as there are in the wild in India, which is thought to shelter the world's largest free-ranging population.

A farm-raised moose can live as long as 18 years, although few of them reached that age because of the depredations of wolves, bears, and poachers on the free-ranging population.

The National Park Service policy is to keep bear-human contact to a minimum and to insure a free-ranging grizzly population dependent solely on natural food sources, including berries, rodents and large mammals like deer.

A portion of the newly hatched adults are harvested for the insect trade while the rest are released to complement the free-ranging population.

As of 2005, a cooperative venture between the Zoological Society of London and Mongolian Scientists has resulted in a free-ranging population of 248 animals in the wild.

While Fire Island was exempted from this rule since its deer are not hunted and tend to stay on the island, darting a free-ranging population elsewhere without trapping and tagging is not yet possible.

The captive population in China has increased in recent years, and the possibility remains that free-ranging populations can be reintroduced in the near future.

The island has a free-ranging population of about 950 Rhesus monkeys.

But Colorado Department of Wildlife veterinarian and CWD expert Mike Miller warns, "Given existing tools, it seems unlikely that CWD can be eradicated from free-ranging populations once established."