The tiny mouse-sized pygmy tarsier is a nocturnal primate native to Indonesia. They’re not monkeys, but prosimians, like lemurs. They have big eyes like a Furby, but are only 4 inches long, and most of that was tail. Precious little was known about them, as they were believed to have gone extinct in the early 20th century. Yet in 2000, a scientist found one…in a rat trap…sadly very much dead.
If you’re the kind of person who prefers to call werewolves lycanthropes, you, like me, hear the name Tasmanian tiger and immediately correct it to thylacine. The thylacine was native to the islands of Tasmania, obvs, and New Guinea, as well as the Australian mainland, where it had been evolving away happily for 2 million years ago or so. It is called the Tasmanian tiger because of its stripey lower back, though the less-used name Tasmanian wolf is at least as appropriate for its canid-like characteristics. They were the largest known carnivorous marsupial in the world, about two feet tall and weighing about 60lb/27kg, the size of a dog who’s not quite big enough to be a ‘big dog” but still too big to let you get a lease to a lot of apartments. The thylacine was a nocturnal hunter, though scientists debate what its primary food source was, if it went after lots of tiny creatures, like the antechinus, or a few larger creatures, like wombats. Bonus fact: the male antechinus is so utterly dedicated to mating during the mating season that he’ll go at it for 12 hours straight for days on end, not bothering with paltry things like food, water, or sleep, until he actually mates himself to death. The thylacine was one of only two marsupials known to have a pouch in both sexes: the other species, which is still with us, is the water opossum from Central and South America. The pouch of the male thylacine served as a protective sheath, covering their genitals, making them sort of internal external reproductive organs.
Roughly 2,000 years ago, the pouched predator disappeared from Papua New Guinea and Australia, perhaps due to competition from the dingo. The dingo is considered the first introduced species in Oceania, though no one’s quite sure who brought them. Among the front-runners are Indian mariners who may have traveled to Australia, the seafaring Lapita people who spread eastward into the Pacific from East Asia, and traders from Timor and Taiwan who sailed throughout Southeast Asia. Anyway, the dingo began outcompeting the thylacine centuries before European settlement, at which point there were around 5,000 thylacines.
Things got worse for the tigers in Tasmania after sheep were introduced in 1824. The European settlers took a dim view of native animals eating the livestock they’d introduced into the predator’s environment. Within a few years, cash bounties were offered to encourage people to hunt them, despite contemporary evidence that stray dogs and poor ranch management were killing most of the sheep. Nope, gotta be this animal we didn’t ask for. Add to the bounty-hunting the combo punch of extensive habitat destruction and invasive diseases like mange, and the population diminished rapidly.
The last living thylacine was captured in the wild in 1933, before being taken the Beaumaris Zoo, also known as the Hobart Zoo, the remains of which you can skulk through if you’re into urban exploring and don’t mind the risk of being arrested for trespassing. Workers at the zoo named the tiger Benjamin. You might have see footage or still images of Benjamin; if not, there’s a link in the shownotes. More footage was found in recent years, in which Arthur Reid, then-owner of the zoo, literally rattles Benjamin’s cage, presumably to try to get him to do something for the camera. Reid would die later that year and the zoo changed ownership. Whether owing to the new zoo’s new owners or random negligence, one freezing night in 1936 Benjamin was locked out of his shelter, forcing him to sleep exposed on the concrete slab and he died of exposure. The local paper the Mercury said at the time that the thylacine had been in “splendid health and condition, but, unfortunately, contracted a chill during the recent spell of cold weather.” Yeah, I guess that’s one way to put it. To make the matter sadder, like a death row call from the governor coming too late, the thylacine had been given government protection two months earlier. Fat lot of good that did.
The zoo that failed to provide basic care to what they thought-slash-knew at the time to be the last of its species, posted ads offering to pay trappers for a new thylacine specimen, and the government circulated questionnaires to identify any sightings of the animals, but none ever turned up. No confirmed thylacine sightings have been recorded in the 90-odd years since Benjamin’s unceremonious demise, despite intensive searches and hefty rewards offered for convincing evidence. The species was declared officially extinct in 1982, but the Australian government has revised this timeline to mark the thylacine as having gone extinct in 1936 when Benjamin died. Some people do hold out hope, though. Reports come in now and then of people in the bush who think they saw a ‘Tassie tiger,’ but no such reports have yet to turn up a tiger. That’s actually okay by Nick Mooney, a thylacine expert, “If they are there, I hope we never find them because we are even greedier now,” he adds.
Although extinction is a natural phenomenon, it occurs at a natural “background” rate of about one to five species per year. Scientists estimate we’re now losing species at 1,000 to 10,000 times the background rate, with literally dozens going extinct every day through habitat destruction, exploitation, and climate change. Sometimes, though, we really excel ourselves. Take for example the passenger pigeon. Possibly the most abundant bird on earth, early nineteenth century estimates put their population at somewhere between three and five billion with a B individuals, about a third of today’s North American bird population. Records in the 1830’s tell of passing flocks that darkened the skies for several days at a time. They nested in trees in such great numbers that their weight would break off branches. There were contests to shoot as many of them as possible during a certain period of time, with one winner shooting 30,000 birds. By 1900, there were none left in the wild. The last captive specimen, a pigeon called Martha in the Cincinnati Zoo, died in 1941.
The history of the passenger pigeon can teach us a lot about how and why species become extinct. Native Americans also relied on passenger pigeons for food, but by and large had learned to harvest the species to a sustainable level. It was common in some parts of North America to only eat young pigeons that were hunted at night, since this did not seem to scare away the adult birds or prevent them from re-nesting. But starting around 1500, a more aggressive variant of humans came to the continent. Were Europeans to blame for the extinction? Not entirely (though still mostly).
A 2014 study published in the scientific journal PNAS strongly suggested that humans were simply the final straw in destroying a species that was already vulnerable and headed to oblivion. The researchers asserted that despite their enormous numbers, the passenger pigeons, who population figures could vary widely, were already in trouble.
Studies of the genetic variation of the species using an investigative method called PSMC formed the background for these theory. The PSMC, or Pairwise Sequentially Markovian Coalescent, method can use the information in the genes of a single individual of a species to map the history of the species. You should therefore be able to see how the species developed over many generations, and estimate how many individuals there were at any given time, all based on a single genome. Using this method, researchers found that the number of passenger pigeons was in free fall even before the arrival of the Europeans. Although the species might not have gone extinct, left alone, it would have shrunk dramatically, maybe to only a few hundred thousand individuals.
It sounds almost too good to be true that you can come up with something so definitive based on information from just one or a few individuals. And in this case it is — at least if we believe a new study published in the journal Science. That study claims the PSMC method can’t be used on passenger pigeons. Their research provides completely different results. PSMC is based on the assumption that genetic variations occur relatively evenly all along the chromosomes that constitute the genome. In passenger pigeons, most of the genetic diversity was found at the *ends of the chromosome. The middle of the chromosome showed little variation from one generation to the next as a result of the selection on these genes.
The researchers behind the article in Science didn’t use the PSMC method, but instead used mitochondrial DNA from 41 passenger pigeons as their starting point. Science nerds and true crime buffs will know that mitochondrial is passed down from your mother, from her mother, and so on and does not contain DNA from your father. Variations in mitochondrial DNA also occur due to mutations, and happen relatively consistently over time. The study in Science analysed the entire genomes from four passenger pigeons and compared them with two genomes from band-tailed pigeons, one of their closest relatives. The final result was that the new study ended up with completely different answers about the passenger pigeons and why the species met its demise.
Scientists previously believed that the larger the population of a species is, the more genetically diverse it will be, but this proved not to be true with passenger pigeons. According to the article in Science, the large population size appears to have enabled passenger pigeons to adapt and evolve more quickly. The fact that beneficial mutations became incredibly dominant so quickly simply led to the disappearance of other genetic variants. This in turn led to the genetic diversity in the passenger pigeon being surprisingly low in relation to their numbers. This may have made the species more vulnerable to changes. The large grasshopper Melanoplus spretus from the western United States suffered the same fate. It went from a population of several trillion to zero in a few decades, possibly because farmers destroyed its breeding grounds.
While a lack of genetic diversity made the passenger pigeon susceptible to change, it was still ultimately humans that did it in. People ate passenger pigeons in huge amounts, but they were also killed because they were perceived as a threat to agriculture. As Europeans migrated across North America, they thinned out and eliminated the large oak forests that the pigeons depended on for their primary food, acorns. The advent of the locomotive was a boon to the commercial pigeon hunter, because it meant great barrels of the little birds could be loaded up and sent to other cities. The pigeons were probably dependent on a large flock size to reproduce. Their instincts didn’t work when only a few individuals remained here and there. As the species was already dying out, 250,000 birds, the last big flock, were shot on a single day in 1896. That same year, the last passenger pigeon was observed in Louisiana. It was also shot.
Shooting the last of something is sadly not rare in the annals of animals that aren’t here anymore. The culprit here is less the hunter than it is his boss, a private collector or even a scientific institution. History is littered with the stuffed and mounted carcasses of animals that were the last of their kind, bagged by overzealous collectors who didn’t stop to consider the cost of the kill. In collecting’s heyday, bagging a rare species was a point of pride for naturalists, and wealthy wildlife lovers amassed taxidermied animals the way another person might accumulate art. Famous scientists like Charles Darwin and Alfred Russel Wallace collected and preserved hundreds, thousands, even tens of thousands of specimens — most of which served a vital role in making new species known to science. But collectors, who traveled to the world’s most remote regions in search of as-yet-unknown animals, also had an Indiana Jones-like swagger. Competition to find something first was fierce, and institutions vying for new and exotic specimens meant that dozens of researchers would go tramping up mountains and into jungles to kill the same animal.
Among the most famous victims of this is the great auk, a now-extinct North Atlantic bird with a penguin’s tuxedo-like plumage and ungainly waddle. It’s population had been decimated by demand for its down feathers. The species was already teetering on the brink when naturalists and museums took an interest in it in the 19th century. Climate change during the Northern Hemisphere’s several-century cool spell known as the “Little Ice Age” had decimated the population. Humans then finished the job. The birds stood nearly three feet tall and sported thick, plumage, making them a valuable food source and even more valuable commercial product. Adding insult to injury, its clumsiness on land (and inability to fly) made it an easy target for hunters.
Paradoxically, it was the great auk’s sudden rarity that made scientists so eager to kill them. According to the Smithsonian, the great auk’s classification as endangered in 1775 led to increased demand for specimens — a single bird could be sold for $16 in the early 1800s, a full year’s wages. No longer hunted for its meat and down, the great auk and its eggs became a target for their scientific value. On July 3, 1844, a group of fishermen caught two of the birds on a remote island off the Icelandic coast. The fishermen strangled the birds to kill them with minimal damage to the body and crushed the egg they were brooding. They didn’t even get a meal out of it, which you could at least respect a little. The birds’ carcasses were sold to a chemist in Reykjavik, who stuffed and mounted the birds, then preserved their eyes and internal organs like pickles in jars of alcohol. No one on record has seen a great auk since.
The great auk was actually the logo for something I did in elementary school called the Knowledge Master Open, a kind of battle of the brains tournament. We were eliminated in the first round, dead as a dodo. The dodo, of course, being the poster child for extinction, probably because we effectively lost the species twice. (How’s that for a segue?)
Most people are familiar with the sad story of the dodo. This plump, flightless bird was so tasty and so tame that it was hunted to extinction within a century by Dutch sailors arriving on the island of Mauritius in the Indian Ocean. Fewer people realise that this story is mostly false. Were these flightless birds tasty? Probably not, since the waste pits from the early Mauritian settlements are full of animal bones from the Dutch dinner table, but there is not a single dodo bone amongst them. Dodos also weren’t as plump as you see in illustrations. The pictures our pictures are based on were probably made of overfed captive birds or poorly-taxidermied specimens. In the wild, the dodo was a much leaner bird. Were they hunted to extinction? Unlikely – Mauritius was blanketed in thick impenetrable rainforest, and dodos deep in the heartland would have been well beyond the reach of even committed hunters.
How can such an icon of human-induced extinction be so misunderstood? The answer lies in the shameful way the dodo was treated *after the last bird died about 350 years ago. “We have this continuous series of tragedies, forgetting the dodo over and over again,” says Leon Claessens at the College of the Holy Cross in Worcester, Massachusetts. But perhaps no longer. Because of the work of Claessens and his colleagues – including Julian Hume at London’s Natural History Museum and Kenneth Rijsdijk of the University of Amsterdam – science is finally giving the dodo the attention it deserves.
It is difficult to trace that evolutionary process due to the island’s acidic soil and humid tropical climate, which make for an unforgiving environment for fossils. All we can say for sure is that the dodo evolved at some point in the last 8 million years – simply because it was 8 million years ago that Mauritius, a volcanic island rather like Hawaii, first rose above the waves.
Of course, the dodo’s extinction is sadly easier to pin down than its origins. Dutch sailors probably first encountered the bird in 1598, but the sailors themselves did not make much of a contribution to the dodo’s extinction, says Claessens. “At most there were a few hundred people living in a coastal settlement.” The problem was more likely the ship rats and other animals they brought with them, which spread across the island, eating dodo eggs and outcompeting the birds for food.
The last confirmed sightings came in the 1660s. The living dodo was lost forever, but specimens of the strange bird had already been sent to Europe for scientific study. In several museums and university collections, skeletons and stuffed dodos survived. Unfortunately, Europe’s 17th-Century scientists did not realise quite how valuable their dodo specimens were. The problem was that the dodo had disappeared at the wrong time. Its extinction came long before scientists were willing to accept that species really could vanish forever. The great French palaeontologist Georges Cuvier is widely credited with alerting the scientific world to the reality of extinction, but he did not do so until 1796. This meant that 17th and 18th Century museum curators felt confident that there were more dodos out there to replace any specimens that became damaged. Specimen damage or loss was common, especially at a time when taxidermy was in its infancy and museum records were relatively crude.
There used to be a complete dodo in Oxford, but they had to discard the majority of the specimen in the 1700s. They kept just the head and a foot. The British Museum also had a dodo foot, but they plum lost track of it about a century ago. There is also a dodo skull in Copenhagen and part of a beak in Prague. That’s about it.
The dodo might have fallen into obscurity forever, if not for the work of two Victorian researchers, Hugh Edwin Strickland and Alexander Gordon Melville. In 1848 they published a monograph, The Dodo and its Kindred. Inadvertently, Strickland and Melville had kick-started a wave of dodo-mania. This arguably reached a peak when the bird featured in Lewis Carroll’s Alice’s Adventures in Wonderland, which I would argue did more to help us remember the dodo than any scientific work.
With all the advances in scientific processes and thinking, we’ve surely moved past hunting specimens for display and study, right? It’s sweet that you think that. In 2015, Christopher Filardi of the American Museum of Natural History scoured the highlands of Guadalcanal in the Solomon Islands for a bird he’d been searching for for two decades: the moustached kingfisher.
“Described by a single female specimen in the 1920s, two more females brought to collectors by local hunters in the early 1950s, and only glimpsed in the wild once,” he wrote. “Scientists have never observed a male. Its voice and habits are poorly known. Given its history of eluding detection, realistic hopes of finding the bird were slim.” But he did it. After setting nets across the forest, he and his team secured a male specimen with a “magnificent all-blue back” and a bright orange face, at which point his team collected it.
Of course, ‘collect’ means killed. While this wasn’t trophy hunting, outrage ensued. The controversy led the Audubon Society, which had previously published a piece innocently titled Moustached Kingfisher Photographed for First Time, to add an editor’s note: “This story has been updated to clarify that the bird was euthanized and the specimen collected.” A researcher on Filardi’s team, it added, “told Audubon that they assessed the state of the population and the state of the habitat, and concluded it was substantial and healthy enough that taking the specimen – the only male ever observed by science – would not affect the population’s success”.
Filardi was also compelled to write an op-ed for Audubon: Why I Collected a Moustached Kingfisher. “I have spent time in remote, and not so remote, forests of the Solomon Islands across nearly 20 years,” he wrote. “I have watched whole populations of birds decline and disappear in the wake of poorly managed logging operations and, more recently mining. On this trip, the real discovery was not finding an individual Moustached Kingfisher, but discovering that the world this species inhabits is still thriving in a rich and timeless way.” Filardi stressed that, among Guadalcanal locals, the bird is known to be “unremarkably common”. He explained how he and his team made the decision – “neither an easy decision nor one made in the spur of the moment” – to collect the bird with reference to “standard practice for field biologists”. And he said that killing one kingfisher might help save them all.
The mustached kingfisher is a fabulously brightly-colored bird. I’ll put a link in the show notes. If you podcast app doesn’t support html, at me on social media. Social media is also a great way to help your favorite podcast by sharing the show with your friends and followers.
Human beings have not been good custodians of the earth and its creatures. There, I said it. It’s the critically endangered Sumatran elephant in the room. We’re so bad at taking care of wild animals, we can’t even take good care of their remains. We can see this clearly with the quagga. What’s a quagga, you ask? Well hold on, I was just about to tell you. imagine you were printing the stripes on a zebra with a brown base coat, working from the top down and ran out of toner before you finished. Once thought to be a separate species, scientists who have performed DNA analyses on modern zebras and quagga remains now say that the quagga is a subspecies of the plains zebra.
Even before you listened to this episode, you could have guessed what happened to the quagga. Humans, particularly European humans, the most invasive species of all. Large scale hunting in South Africa in the 1800s exterminated many animals, and quaggas were hunted to extinction in the late 1800s. They were valuable for their meat and hides, and people wanted to preserve the vegetation quaggas fed on for domesticated livestock. In addition, few people realized that the quagga was distinct from other zebras and needed protection. The last wild quagga was probably killed in the 1870s, which was about the same time the only photo of a living quagga was taken, of a mare at London Zoo. The last captive quagga died in an Amsterdam zoo on August 12, 1883. This left the world with a few dozen preserved hides and about seven skeletons to remember the species by.
The Grant Museum of Zoology in London houses one of these skeletons, though they didn’t know it. They had two “zebras” listed among their exhibits. In 1972, the world’s foremost quagga expert came to check out the zebras only to declare that one of them was in fact one of the world’s rarest skeletons. Quite an upgrade. The other zebra skeleton was also not a zebra, but that turned out to be a donkey, [sfx] a significant demotion in zoological terms. The Grant Museum’s quagga not quite a complete skeleton as it’s missing a rear leg. The most likely story is that the leg was on loan to the Hunterian Museum at the Royal College of Surgeons during WW2. This building was bombed during the Blitz, and part of their collection was destroyed, including – it’s believed – the quagga’s leg. WW2 is for London like me and my two house fires — I assume that’s what happened to anything from my earlier life that I can’t find now.
A group called the Quagga Project, started by Cape Town University professor Eric Harley, is working to bring the quagga back from the dead. Testing remaining quagga skins revealed the animal was in fact a sub-species of the plains zebra. Harley hypothesized that the genes which made quaggas quaggas would still be present in the DNA of the zebra, and could manifest through selective breeding. So that’s what they’ve been doing. With each new group of foals, the distinct colorings have become stronger and more defined.
“The progress of the project has in fact followed that prediction. And in fact we have over the course of 4, 5 generations seen a progressive reduction in striping, and lately an increase in the brown background color showing that our original idea was in fact correct,” says Harley.
The project has not been without its critics. Some have called the project a stunt, saying all that’s been created is a different looking zebra, without taking into account the ecological adaptations or behavior differences in the original quagga. Another project lead admits, these animals “might not be genetically the same,” and “there might have been other genetic characteristics [and] adaptations that we haven’t taken into account.” As a concession to the not-invalid detractors, these new quasi-quaggas are called “Rau quaggas,” after Reinhold Rau, one of the project’s originators. “What we’re saying is you can try and do something or you could just not,” argues Gregor. “And I think us trying to do, trying to remedy something, is better than doing nothing at all.” And he’s not wrong there.
And that’s… But that wasn’t all for the pygmy tarsier. In August 2008, a research team came across four pygmy tarsiers at Lore Lindu National Park in central Sulawesi. Hailed as a “rediscovery,” the species’s status as extinct was officially debunked. Using mist nets, the researchers successfully captured two males and a single female, then fitted each with a radio collar to track their movements before releasing them. The fourth pygmy tarsier in the quartet eluded capture, escaping into the forest, so who knows how many there really are?