In a more recent example, you had the domestication of silver foxes during the 1960s in Russia, as a science experiment studying domestication. After the collapse of the Soviet Union the research program has had budget problems, and only a small population exists (now down to 100), but there is still some ongoing study into the genetic aspects of domestication, and I guess the tame foxes are sold as pets too.

Source: Lyudmila Trut (the current researcher) wrote an article in American Scientist about it: "Early Canid Domestication: The Farm-Fox Experiment"

There is a wiki page for more casual reading, it links to said article: http://en.wikipedia.org/wiki/Domesticated_silver_fox

Are you asking about animals that used to be kept, but escaped/were released and are now wild again? Or are you asking if there were animals domesticated for a particular use but are no longer being used for that purpose?

Also - would you include pets as part of your question, or purpose aminals?

Wild horses in the American West? I seem to recall that some of these herds are the direct descendants of escaped Spanish horses from the early Conquistador times. At any rate, these were domesticated and now have got back to being wild and are harder to tame than "bred" domesticated horses.

Edit: Additionally, Australia has a sizable population of wild Camels (http://en.wikipedia.org/wiki/Australian_feral_camel)

Australia has a fantastic population of feral camels, originally brought over to act in place of horses for desert caravans. There's a documentary called Ships of the Desert. Also feral horses (brumbies), and other feral critters.

Geese are still domesticated (as much as geese can be called domesticated) in some places like France, but not so much in others like the eastern seaboard of the U.S. where they used to be common.

Sorry, we don't allow throughout history questions. These tend to produce threads which are collections of trivia, not the in-depth discussions about a particular topic we're looking for. If you have a specific question about a historical event or period or person, please feel free to re-compose your question and submit it again. Alternatively, questions of this type can be directed to more appropriate subreddits, such as /r/history or /r/askhistory.

Alternatively, /r/AskScience might be a great place to ask about domestication of animals, and feral populations.