There’s not a lot that’s actually known about the massive creatures known as Steller’s sea cows, because in the 27 years between their identification and their complete extinction, only a single scientist — Georg Wilhelm Steller — ever saw one alive. The only others to see living sea cows were those who were trying to kill them, and yes, that’s absolutely why they’re not around anymore.

According to the Natural History Museum, Steller’s sea cows could grow to be more than 30 feet in length and weigh around 11 tons. And that was part of their downfall: A single sea cow was enough to feed a ship’s crew for a month. Steller, a German zoologist, first documented the sea cow in 1741 in the Bering Sea. Unfortunately, they were right in the middle of prime hunting ground for fur traders looking to kill and skin vast numbers of sea otters to supply the fur trade and the fashion industry. As hunters moved through looking for otters, they’d kill sea cows to keep them supplied with meat for their journey between Russia, Japan, and North America. It was such a massive industry that by 1768, Steller’s sea cows — which were probably rare when they were discovered — were completely extinct.

The museum’s Principal Curator of Mammals, Richard Sabin, explains: “They are held up as an example of the first sea mammal in modern times made extinct by human ignorance and greed.”

Parrots are some of the world’s coolest birds, and yes, there was a parrot that was native to the U.S. It was just a single species called the Carolina parakeet, and they were brightly colored green, yellow, and orange birds. Cool, right? Unfortunately, we’re talking about extinction, so you know where this is going.

According to National Geographic, the last Carolina parakeet was a captive one, and died in 1918. It was pretty shocking: At one time, they’d had a native habitat that reached from Florida to Pennsylvania to Nebraska. Recent studies have confirmed that yes, mankind is responsible for this one, too. Way to go, humans.

There were a few things working against the Carolina parakeet, and that includes rapid habitat loss thanks to expanding city and suburban centers. But they also had problems with farmers, who considered the once-large flocks they lived in to be nothing more than airborne pests. Not only did they kill individual birds, but Carolina parakeets were known for congregating around their dead, which allowed farmers to kill entire flocks at a time. They also suffered severe habitat loss due to clearing for the agricultural sector, and their feathers were so pretty that they became a popular fashion accessory when people decided they wanted to wear the feathers, instead of admiring the birds they belonged to. Now, no one can enjoy them.

Sometimes, we know exactly when the last of a species died, and that’s the case with the Great Auk. Standing about three feet tall, one of the last of these flightless birds was spotted by three Scottish sailors in 1840. Graceful in the water and ungainly on land, it was easy for them to catch the bird and carry it back to their ship. When they set sail and storms started, they became so convinced that the bird was a witch that had cursed them with the storm that they stoned it.

That was the last Great Auk of the British Isles, and the species died completely just four years later when fishermen chased and killed the last two — a breeding pair — and stepped on the last Great Auk egg. Explorers had been warning of the imminent destruction of the species since at least 1785. That, says the Smithsonian, is when George Cartwright condemned the practice of killing scores of Great Auks and collecting feathers for eiderdown.

Pre-16th century, there were hundreds of thousands of birds living in vast colonies along the northern Atlantic. By the mid-1500s, though, explorers had discovered the treasure trove of eggs and meat, and helped themselves without a second thought. Ships hunted — then salted and preserved — them by the barrel, and even though there were attempts made to save them, a single Great Auk specimen was simply worth too much money for people to resist.

Audubon estimates that in their heyday, the passenger pigeon was at least the most numerous bird on the North American continent. Author and conservationist Aldo Leopold called them “a living wind,” and when Potawatomi tribal leader Simon Pokagon wrote about them in 1850, he described flocks as sounding like “an army of horses laden with sleigh bells was advancing.” Birds traveled in flocks of hundreds of thousands of individuals, with some estimated to be in the millions. So many would nest in trees that their collective weight would snap branches… so, what the heck happened?

The last passenger pigeon died in 1941. Her name was Martha (pictured), and she was 29 years old. By that time, the species had been destroyed by mass slaughter that included everything from poisoned corn to swatting them out of the sky with poles to simply shooting them.

Seen as both a nuisance and a source of easy meat, the development of the telegraph and improvements to the country’s transportation system allowed people to essentially follow the flocks — and find new ones. An entire industry formed around the wholesale slaughter of the pigeons, leading Pokagon to later wonder what otherworldly justice was “awaiting our white neighbors who have so wantonly butchered and driven from our forests these wild pigeons, the most beautiful flowers of the animal creation of North America.”

Take a dingo. Now, give it the coloring of a zebra on the back end, and a pouch like a kangaroo… only, make that pouch open to the back instead of to the front. That’s pretty much an explanation of the creature known as the Tasmanian Wolf, Tasmanian Tiger, or thylacine. The Australian Museum says that the thylacine was the only one of that particular branch of the evolutionary tree that was around in our modern era, and guess what happened to them?

The last captive thylacine died in 1936, says MongaBay, and for a long time, it was believed that a farmer named Wilfred Batty shot and killed the last wild thylacine in Tasmania in 1930. (It’s currently thought they survived much longer than that — into the 21st century — but that hasn’t been proven.)

For the most part, thylacines hunted birds, rodents, and the occasional kangaroo. When Europeans settled Australia, though, they quickly gained a reputation — which may have been completely undeserved — for hunting domestic livestock like sheep and chickens. Scientists believe that it was a perfect storm of factors that pushed this pouched dog to extinction, including widespread hunting by farmers claiming to be protecting their livestock, conflict with dogs introduced by Europeans, and habitat loss that pushed them into close competition with Australia’s native dingoes. (And now, some dingoes — like the Australian alpine dingo — are  classified as vulnerable to extinction.)

The story of the tarpan is a weird one, and it starts way back in prehistory. According to ThoughtCo., the tarpan emerged victorious after an Ice Age wiped out all their cousins, and it was the tarpan that was first domesticated by early humans. Ancient Roman writings talk about the vast herds of tarpans that ran wild, and here’s where humans start ruining things.

By the 18th century, these wild horses were already nearly extinct. Why? Partially because they were tasty, and were widely slaughtered for their meat. There was another problem, though: Since they were capable of interbreeding with domestic horses, that’s exactly what they did. The result was fewer and fewer pure tarpans left in the wild, and the last died — while being chased by people — in 1879. Eight years later, the last captive died. 

But here’s where things get super weird. In Nazi Germany, a zoologist named Lutz Heck decided that he was going to reverse engineer horses into tarpans by selectively breeding for certain traits, like hardiness, appearance, and super-fast healing abilities. And the Smithsonian says that he sort of did. He ended up creating a breed that still lives in the forests of Poland, and while they’re still tainted by their association with the Nazis, the so-called near-tarpans are now credited with helping to stabilize the ecosystem of Bialowieza.

As the world entered the dawn of the 20th century, there were somewhere around a million black rhinos living in areas across Africa. They were officially declared extinct in 2011. So, what the heck happened? According to Scientific American, fortunes started changing for the western black rhino with the development of sport and trophy hunting. That put a serious dent in the population, and that was followed up by the clearing of land and culling of rhinos as commercial and industrial agriculture became more important than native species.

By that time, it was the 1950s, and here’s where Chairman Mao comes in. Not only did Mao Zedong take over China, but he also started guiding the nation’s daily life. That included the promotion of traditional Chinese medicine, and even though he didn’t actually believe in it, he was an incredibly vocal proponent of the use of things like powdered rhino horn. It was said to cure pretty much anything, and it was in such high demand that when poachers realized they could make a fortune slaughtering animals for their horns, that’s what they did. By 1980, there were only 135 western black rhinos left, and they were spread so far apart that there was little chance of them meeting — or of making new rhinos.

By 1997, there were 10 left. Six of them died alone, miles apart.

In 2011, the U.S. Fish and Wildlife Service took a look at the species that it had listed as endangered. On the list was a North American big cat called the eastern cougar, and it had been lingering for a long time. The species was officially declared extinct in 2018.

Officials think that it had been a long time coming, and say that most eastern cougars had died in the 1800s. As people expanded their territory, these big cats were hit with a triple whammy: Not only did they lose their natural habitat, but their favored prey — white-tailed deer — was slaughtered wholesale by those same encroaching humans, and those humans were also killing the cats themselves. Why? Because they were scary, and they had pelts that were incredibly useful.

National Geographic says that the problem with pinpointing just when the eastern cougar went extinct happens because they’re incredibly solitary, shy creatures who travel at night and prefer to avoid people. They also say that confirming the cats’ extinction might work out all right, and could help protect other big cats. Conservationists are seeing an across-the-board decline in large predators, which is leading to an unbalanced ecosystem. It’d be awesome if people learned from cases like the eastern cougar, and it was perhaps Michael Robinson of the Center for Biological Diversity who put it best when he said, “To know the world is not entirely dominated by humanity is a peace of mind.”