It doesn’t take an asteroid strike, climate change or another mass extinction event to kill off animals — extinction of a species could result from completely avoidable conditions. Plenty of animals have gone extinct in recent centuries, and many of them have humans to thank for hunting them and invading their habitats. Here are four of the most devastating recent cases.

Tasmanian tiger

Thylacinus A male and female Tasmanian tiger, believed now to be extinct, are shown at the National Zoo in Washington, D.C., around 1906. Photo: Public domain

The Tasmanian tiger shared a name with felines and the face of a dog, but it was actually a marsupial from both Tasmania and the Australian mainland that went extinct in the 1930s, with the help of humans. Also known as thylacine or a Tasmanian wolf, the creatures were sandy-colored with dark stripes on their backs and were about 4 feet long if you didn’t count their tail, which looked like it came from a kangaroo and added a couple of feet to their appearance. Also like a kangaroo, the females had a pouch to carry their young.

Read: The Most Iconic American Animals That Have Gone Extinct

The Tasmanian tiger has a sad story, but might have a happy ending. Experts believed the animal went extinct decades ago, after the last wild one was shot in 1930 — it was often at odds with humans for preying on sheep — and the final captive marsupial died a few years later, but there have been plausible reported sightings. According to NPR, scientists are searching for the Tasmanian tiger, which is closely related to the Tasmanian devil, in the hopes it can be removed from the list of extinct species.

Falkland Islands wolf

FalklandIslandFox2 A Falkland Islands wolf, also known as an Antarctic wolf or a Falkland Islands fox, was a dog relative that went extinct in the late 1800s thanks to human hunters. Photo: John Gerrard Keulemans/public domain

This animal, also known as a warrah or an Antarctic wolf, was hunted to extinction in the 1870s. But although it appeared similar to a wolf or a fox, it was actually a different kind of dog all together.

As its name suggests, it lived on the Falkland Islands, off the southeastern tip of Argentina, close to where South America tapers off and reaches its nearest point to the Antarctic Peninsula. On those islands, the wolf was completely disconnected from the rest of the world, including most other species — it was alone for thousands of years with seabirds, penguins and seals, according to researchers. That was until humans showed up. National Geographic explains that its friendliness made it easy to kill.

Sea wolf

caribbmonkseal-newyorkzoologicalsociety1910 A Caribbean monk seal, also known as a sea wolf, in captivity at the New York Aquarium around 1910. The seals would go extinct a few decades later, due to hunting by humans. Photo: Public domain

The Caribbean monk seal, which was also known as a sea wolf or a West Indian monk seal, was a social creature about 8 feet long and could weight up to 600 pounds, according to the U.S. National Oceanic and Atmospheric Administration. The brown or gray seals fed on fish and crustaceans in the Caribbean Sea, the Gulf of Mexico and the western Atlantic Ocean.

But the seals, which were not aggressive and thus more approachable, were hunted for fur, meat and oil as soon as Spanish settlers came over from Europe in the late 1400s. They disappeared in the early 1950s, and several years ago NOAA confirmed that overhunting was the cause of their believed extinction.

Read: Extinct Australian Turkey Was As Big As a Kangaroo

The bad news doesn’t end there, however: Two of the Caribbean monk seal’s relatives, the Mediterranean monk seal and the Hawaiian monk seal, are endangered as well.

Quagga

Quagga An extinct subspecies of zebras known as the quagga is shown at a London zoo in 1870. Photo: Frederick York/public domain

The quagga, a subspecies of zebra, was once common in South Africa, but European settlers hunted them to the extreme for the meat and fur. Although some scientists are trying to bring them back using a selective breeding process that could take zebras and guide them in their evolution into quaggas, the last known quagga died by the 1880s. The last wild one was probably killed in the late 1870s, followed a few years later by the final quagga in captivity — a mare died at a zoo in Amsterdam in 1883.

The extinct animals with stripes looked similar to other zebras, which are related to horses, but they had stripes on their front halves that faded toward their midsections and turned into more solid brown fur on their back halves.