Museums have a gender equality problem. Wander the halls of any natural history gallery and chances are, you’ll see more male than female specimens on display.
Researchers at London's Natural History Museum analysed 2.5 million records from five prominent museums around the world and found that just 40 per cent of bird specimens are female, while 48 per cent of mammal specimens are female. This slight percentage difference equates to 40,000 more male mammals housed in museums.
It’s not just an issue for the stuffed display animals, either—the male bent also afflicts research collections. When it comes to type specimens—the ‘official’ specimen used to scientifically describe a species—the sex ratio drops further, with just 27 per cent of birds and 39 per cent of mammals being female.
These ratios have remained unchanged for the last 130 years, except in species with marked sexual dimorphism. This is where males have ostentatious features such as bright colours while females may be more understated in appearance. In such species, the proportion of females in museum collections has decreased.
This bias towards males has implications for our understanding of evolution, genetics and ecology.
“Natural history collections play a critical role in … answering vital questions for the future of biodiversity,” the study authors wrote. “These results imply that previous studies may be impacted by undetected male bias, and vigilance is required when using specimen data, collecting new specimens and designating types.”
On Scotland’s remote St Kilda island in the summer of 1840, a group of fishermen found a strange seabird sleeping on a ledge. It was black-and-white, flightless, and enormous. The men took it home to their village and tied it up in a stone hut.
For three days the bird complained and tried to bite anyone that came near. Then a wild storm arose. Fearful the bird was a witch, and had sent the tempest to punish them for capturing it, the superstitious villagers stoned it to death. It took an hour to die.
In reality, the witch-bird was a great auk—the last one ever documented in the British Isles. Four years later, the last pair in existence was killed in Iceland by hunters looking for museum specimens.
The species—sometimes known as the penguin of the north—had ranged across the North Atlantic in the millions. What happened? Was the species in decline before intensive harvesting started in the 1500s—or was human hunting alone enough to drive such a numerous species into oblivion?
To find out, genetic researcher Jessica Thomas from the University of Swansea analysed the mitochondrial DNA of 41 long-dead great auks. The data showed the species had enjoyed high genetic diversity and a constant population size for thousands of years, and that great auks from across the North Atlantic were able to meet and breed.
The researchers then simulated how much hunting would have been necessary to drive the great auk to extinction within 350 years, and found that an annual harvest of 210,000 birds and fewer than 26,000 eggs would have inevitably led to extinction.
Sailors’ journals and other historic reports suggest the actual number of birds killed for their meat, eggs, and feathers is likely to have been far higher. Then the museum trade finished them off.
“There are lot of very gruesome sailors’ records in terms of how they used to kill them,” says Thomas. “They would have these huge pits where they would corral the great auks into stone huts and then burn them with the oil from their dead relatives.”
The study highlights that “pretty much anything is susceptible to extinction”, says study co-author Michael Knapp from the University of Otago, where Thomas was based for some of her research.
“People went to the North Atlantic and it was full of great auks. Nobody would have thought there was any risk.”
Some of the great auk’s relatives—the puffin, the murre—are still hunted today, and should be more closely monitored, says Knapp. “Anything we exploit in large numbers we need to be very careful about, even if we think there’s a lot of them.”
Episode Three: Revolutions tells the stories of the objects and events generated by the Silk Road that helped to inspire revolutions. Paper-making spread from China throughout Asia and beyond. After the invention of the first printing press in 1440, millions of Europeans were reading printed content in multiple languages. Paper and the printing press democratised knowledge. Another world-changing implication of east-west trade was triggered by the Ottoman conquest of Constantinople, which blocked European access to the Silk Road. Christopher Columbus searched for another route to Asia by sailing west across the Atlantic and instead landed in the Americas. Jesuit missionaries in China forged close bonds with Chinese intellectuals and introduced Chinese civilization to Europe. Gunpowder transformed mining and helped to make New York a great city.
Light From Darkness explores how deathly disease and new life alike travelled along the Silk Road to change the world. Journey through time, from the decimation of the Black Death to a grain that helped to overhaul agriculture. When the Black Death reached Europe, it spread about 5 miles per day. In a surprising twist, the plague triggered positive change for some Europeans. When the lethal disease wiped out much of Europe’s work force, the nobility were forced to compete for surviving workers by offering higher compensation. A middle class was born. Explore the important highs and lows of bio-migration during the history of the Silk Road. This episode investigates the way living things, ranging from millet to pathogenic liver fluke, reached Europe – with dramatic consequences.
War explores how the Silk Road influenced conflict, from cavalry warfare to gunpowder. The series opens 2000 years ago, when the Roman Empire seemed unstoppable. However, the Battle of Carrhae saw one of Rome’s worst military defeats when the Parthians used cavalry tactics to their advantage. The style of cavalry warfare developed by Central Asian horse archers would later dominate warfare, made possible by several innovations; the recurved composite bow, socketed bronze arrowheads and a psychological shift towards cohesive groups of soldiers under military command. It was also around this time that the Roman Empire began to covet Chinese silk. Long distance trade between the peoples of Eurasia was nothing new; for thousands of years, similar relations had been impacting societies.
No portraits exist of one of the most important people in Pacific history. Tupaia was a man of many talents: high priest, artist, diplomat, politician, orator and celestial navigator. After fleeing conflict on his home island of Ra’iātea for Tahiti, he befriended botanist Joseph Banks, and joined the onward voyage of James Cook’s Endeavour. Arriving in New Zealand in 1769, Tupaia discovered he could converse with Māori. He became an interpreter, cultural advisor and bringer of news from islands that Māori had left long ago.
250 years on, we are barely beginning to know who he was.
It’s not a squirrel, or a bat, but a dinosaur that acted like all three. The newly discovered species Ambopteryx longibrachium lived in the forests of China 163 million years ago, climbing trees and gliding between them.
Ambopteryx, which was described in a paper published in Nature in May, is only the second feathered dinosaur to have been found with signs of membranous, bat-like wings. The first, Yi qi, or ‘strange wings’, reshaped theories about the evolution of flight following its 2007 discovery. (It’s now believed that dinosaurs developed flight up to four times, using multiple types of wings.)
Ambopteryx is a member of the scansoriopterygid family: tiny, feathered, lightweight dinosaurs. Alive, it probably weighed a few hundred grams, or about the same as a burger. It had long hands and fingers, feet suited to perching, and wrist bone called a styliform which looks like it would support a wing.
“These fossils demonstrate that, close to the origin of flight, dinosaurs closely related to birds were experimenting with a diversity of wing structures,” write the authors.
Now, the hunt is on for relatives of Ambopteryx and Yi.
Ornithologists have been arguing for more than a century about just what an adzebill was. Hefty flightless birds with massive beaks, they disappeared in the first wave of extinctions following human arrival in Aotearoa and are known only from their skeletons. Their bone chemistry indicates they were carnivores, and their pick-like beaks and powerful feet suggest they were diggers, perhaps excavating tuatara and seabirds from burrows. But they were apparently unrelated to any living bird species.
When Richard Owen first described them from leg bones in 1844, he mistook them for small moa. Later adzebills were thought to be cousins to the sunbitterns, or the flightless kagu, the national bird of New Caledonia. Were they from the rail family—or something else entirely?
Finally we have an answer, thanks to new techniques that allow palaeogeneticists to extract traces of DNA from ancient bones. An international team of researchers, including palaeontologists and ornithologists from Australia and New Zealand, found that adzebills are relatives of small ground-dwelling birds from Africa, in the obscure family Sarothruridae, or flufftails. The Madagascan wood rail is a typical flufftail—a medium-sized forest bird resembling a weka.
So how did the ancestors of adzebills get from Madagascar to New Zealand? DNA suggests the split happened 40 million years ago, when the southern continents were closer together and Antarctica was further north and covered in forests.
The ancestors of adzebills could fly, and were probably spread across Africa, Madagascar, Antarctica and New Zealand, leaving modern-day descendants at each end of the range. We now know that kiwi, whose closest relatives are the extinct elephant birds of Madagascar, had similarly mobile flying ancestors.
Adzebills turn out to be another native bird that colonised Aotearoa from across the oceans, then lost its ability to fly.