Wikimedia Commons
Wikimedia Commons

9 Ways to Find Age Without a Calendar

Wikimedia Commons
Wikimedia Commons

You can’t ask a tree or a whale how old they are, and most of them weren’t tracked from birth. So how do you tell their age? How do you find out the age of things without a calendar?

1. Dendrochronology

Literally translated, “dendrochronology” is “the study of tree time.” It’s more commonly known as tree-ring dating. Each year, trees in temperate climates form new rings in the summer and winter. During the summer, good growth conditions mean more growth, and less density to the new cells. Growth doesn’t stop during the winter, but instead happens at a much slower rate, forming a dense, dark ring. Rings can be counted while a tree is still alive by taking a core sample—a plug from the tree that goes all the way to its innermost rings. The size of tree rings can show what the environment in a region was like during a certain year, in addition to telling the age of the tree.

2. Otoliths

Removing an otolith from a red snapper, courtesy of Wikimedia Commons, fair use 

All vertebrates have otoliths (“ear stones”). They help us balance and interpret gravity and directional movement, and are pretty much the same size our entire lives. In fish, however, otoliths grow with their bodies, and much like tree rings, fish whose diet changes from season to season will show their age in their otolith rings. As most fish do not truly stop growing as long as they live, their otoliths continue to grow with them, even if it’s just a tiny bit every year.

3. Epiphyseal fusing

Tibia and fibula of 12-year-old, courtesy of Gilo1969, under Creative Commons license 

The epiphysis is a plate of quickly-growing cells at both ends of all long bones in the body. From birth to early adulthood, these plates change size and shape, until they disappear when growth ceases. Before they disappear, their size and degree of closure can give a rough estimate of the age at death of a human or a great ape. However, since those whose epiphyseal plates are visible to the extent of being useful past adolescence are not the norm, they’re most often used to find the age of children and young teens in criminal or anthropological forensic situations.

4. Tooth formation

Image courtesy of Dozentist, under Creative Commons license 

Babies are usually born without teeth, but that doesn’t mean they’re toothless—their teeth are still inside their skulls! Around the ninth week of gestation, there are detectable tooth “buds,” when the primary (also known as baby or milk) teeth begin to form. Even before the primary teeth come in, the permanent teeth begin to form right above them. Between birth and when the full set of permanent teeth come in (generally around 14 or 15), forensic analysis can compare the stage of development of the teeth, and estimate the age based on how far along the process was at time of death. It’s notable that even though wisdom teeth often don’t erupt until the late teens or early 20s, their development is so variable within modern humans (if the person even has them) that they’re infrequently used in aging skeletons less than several thousand years old.

5. Cementum annuli

What if a person’s teeth are already erupted and cemented in place? It turns out that the cementum, which anchors the tooth roots into place, produces microscopic rings of alternating collagen and mineralization patterns, allowing age at death to be determined so long as the remains have intact teeth, and have not been burned. “Cementum annuli” means “yearly cementum,” and we first realized that age could be determined by this method in deer. However, with deer (like many animals), it seems logical that in an environment with alternating food availabilities, the cementum would change patterns. It’s unknown why exactly the cementum does the same thing in humans, but it’s been so highly correlated to known ages that it’s an accepted fact, even without a mechanism of action.

6. Tooth wear

Image courtesy of Ernst Vikne, under Creative Commons license 

You may know what it means, but have you ever wondered where “don’t look a gift horse in the mouth” comes from? Back when gifts of livestock and work animals were common, horses were one of many grazing creatures exchanged. It was considered rude to look in its mouth, because your reason for doing so was to find out how old it was. The eruption and wear patterns on the teeth of many hooved animals are a good way to estimate age, and if you were looking to see how old the horse was, you were being ungrateful for having received the gift in the first place. Don’t ask how much a gift cost, don’t look a gift horse in the mouth, and be grateful for whatever you get—even if it’s a 25-year-old mare whose only use is as a grass trimmer!

7. Amino acid racemization

Antarctic Glaciers 

Living animals have lots of proteins in them. The proteins are made up of amino acids, and with very few exceptions, the bodies of creatures have developed in such a way that all of these amino acids are formed in a “left-facing” orientation. However, when left to their own devices, after a creature dies or a tissue becomes biologically inactive, the amino acids naturally fall into a racemic state—meaning there are equal amounts of left- and right-facing amino acids. The longer a tissue has been inactive, the closer to a 50:50 ratio the amino acids get. While there are many factors that affect how quickly this happens, once the rate of racemization is known, age at death or inactivation can be calculated.

Let's take a look at the inner eye of baleen whales, for example. The whale eye is formed in the womb, and grows by forming new tissue around the existing tissue—so the innermost layer is sort of like a tree core. The inner eye can show how old the creature is; one fin whale that was recently killed was found to have a harpoon from the early 19th century in its blubber, and by calculating the level of racemization of the inner eye, it was determined that it was highly plausible that the individual was an adult when it was first harpooned, and the artifact in its blubber probably wasn’t a fluke or a fake.

8. Carbon-14 decay

Today's Chemist 

While this technique is best known for finding how long it’s been since something died, and has been widely used in the fields of paleoanthropology, the biologically inactive tissues in animals that are used for amino acid dating also have a relatively known level of the radioactive isotope carbon-14. After a tissue becomes biologically inactive, the carbon-14 that’s incorporated into it will decay into the stable carbon-12 at a known rate. The ratio of carbon-14 to carbon-12 is then used to determine a timeline.

If it’s known how long ago something was alive (determined by tissues that are biologically active until death), the carbon-14 ratio in tissues that are biologically inactive after a certain age (such as parts of the adult teeth, after they erupt) can be compared to the time since death, to determine the probable age of an organism. Amino acid dating and carbon-14 dating are often used at the same time, to get a more accurate idea of the probable age at death or tissue inactivation.

9. Earwax plugs


If you’ve ever had problems hearing because of earwax buildup, be grateful you’re not a blue whale! One of the most recently-developed methods of determining age is by taking the earwax “plug” out of a deceased baleen whale. Over its adult lifetime, the whale lays down alternating layers of light- and dark-colored earwax, correlating with its migration patterns and food sources. The earwax plug acts almost like a tree core, and each layer can be independently tested to determine if and when the whale consumed high levels of certain toxins, was physically stressed, or was exposed to radiation or other contaminants. The levels of pollutants and environmental toxins can show how long a certain pesticide, for example, stays in the oceans after it’s banned from use on land.

25 Adorable Facts About Puppies

Everyone loves puppies, we know. It's scientifically proven that they're heart-meltingly cute. But there's more to the little fur babies than just those adorable puppy eyes. In honor of National Puppy Day, here are 25 things everyone should know about these four-legged snuggle buddies.


A dog with a red beret and a scarf.

Etymologists think the term puppy may come from poupeé, a French word meaning doll or toy. The word puppy doesn't appear to have entered the English language until the late 16th century—before that, English-speakers called baby dogs whelps. William Shakespeare's King John, believed to be written in the 1590s, is one of the earliest known works to use the (super cute) term puppy-dog.


A puppy with closed eyes burrows into a white towel.

Puppies are functionally blind and deaf at birth. On day one, their eyes are firmly shut and their ear canals closed. Why? In brief, it’s part of an evolutionary trade-off. Since pregnancy can hurt a carnivore's ability to chase down food, dogs evolved to have short gestation periods. Brief pregnancies meant that canine mothers wouldn't need to take prolonged breaks from hunting. However, because dog embryos spend such a short time in the womb (only two months or so), puppies aren't born fully developed—and neither are their eyes or ears.


A person brushes a collie's teeth.

Like many newborn mammals, puppies are born completely toothless. At 2 to 4 weeks of age, a puppy's 28 baby teeth will start to come in. Around 12 to 16 weeks old, those baby teeth fall out, and by the time pups are 6 months old, they should be sporting a set of 42 adult teeth.


A puppy sleeps against a plush toy.

Like children, puppies need a lot of sleep—up to 15 to 20 hours of it a day. The American Kennel Club strongly advises dog owners to resist the urge to disturb napping puppies, because sleep is critical for a young canine's developing brain, muscles, and immune system. Puppy owners should also establish a designated sleeping space on their pup's behalf so they can snooze undisturbed.


Three bulldog puppies

Purebred dogs can exhibit some extreme bodily proportions, which doesn't always make for easy births. Breeds with atypically large heads are more likely to be born by C-section than those with smaller skulls. A 2010 survey of 22,005 individual dog litters in the UK found that terriers, bulldogs, and French bulldogs had Caesarian births more than 80 percent of the time. The other breeds with the highest rates of C-sections in the study were Scottish terriers, miniature bull terriers, Dandie Dinmont terriers, mastiffs, German wirehaired pointers, Clumber spaniels, and Pekingeses, according to the study.


Brown labrador puppies nurse.

As a general rule, smaller breeds tend to have smaller litters, while bigger dogs give birth to more puppies. The biggest litter on record was born to a Neapolitan mastiff that gave birth via Caesarian section to a batch of 24 puppies in Cambridgeshire, UK in 2004. In rare cases, very small dogs do give birth to relatively large litters, though. In 2011, a Chihuahua living in the English town of Carlisle gave birth to a whopping 10 puppies—twice as many as expected. Each weighed less than 2.5 ounces.


A golden retriever puppy wrapped in a green and white towel

Sometimes, a puppy in a light-colored litter can be born green. On two different occasions in 2017, in fact, British dogs made the news for giving birth to green-tinted puppies. In January, a 2-year-old chocolate lab in Lancashire, UK gave birth to a litter that included a mossy-green pup. Her owners named her FiFi, after Fiona, the green-skinned ogre from Shrek. Just a few months later, a golden retriever in the Scottish Highlands also gave birth to a puppy with a green coat, a male named Forest. How did the puppies end up looking like Marvin the Martian? In rare cases, the fur of a light-haired puppy can get stained by biliverdin, a green pigment found in dog placentas. It's not permanent, though. The green hue gradually disappears over the course of a few weeks.


A puppy stands on a wooden walkway yawning.

Ever notice that when somebody yawns, other people may follow suit? Contagious yawning, thought to be a sign of empathy, affects humans, baboons, chimps, and yes, dogs. But as research published in Animal Cognition suggests, young canines aren't susceptible to catching yawns from birth. In the 2012 study, Swedish researchers took a group of 35 dogs between 4 and 14 months old on closely monitored play dates, feigning yawns in front of each individual animal. Dogs that were less than 7 months old didn't react, yet many of the older dogs would respond with a yawn of their own. This pattern mirrors what happens with humans—children don't pick up the habit of contagious yawning until around age 4, when they start to develop social skills like empathy. These results suggest that dogs, too, may develop empathy over the course of their puppyhood.


A woman holds up a puppy.

Like humans, puppies seem to grow out of baby talk, recent research has found. As part of a 2017 study, 30 women were asked to look at assorted photographs of people and dogs and utter this pre-written line: "Hi! Hello cutie! Who's a good boy? Come here! Good boy! Yes! Come here sweetie pie! What a good boy!" To the surprise of no one, the human test subjects spoke in a higher register while looking at dog pictures, especially puppy photos. Afterward, the researchers played the recordings for 10 adult pooches and 10 puppies. Almost all of the pups started barking and running toward the speaker when they heard the baby-talk recordings. In contrast, the grown dogs pretty much ignored the recordings altogether.


A mother Dalmatian and her puppy snuggle together.

Beloved by firefighters, Disney fans, and George Washington, Dalmatians arguably have the most recognizable coat of any dog breed. Or at least, full-grown Dalmatians do. As puppies, they're born white and spot-less. The markings usually begin to show up after four weeks or so. (A small subset of Dalmatian puppies are born with one or two large black blotches, known as patches, but those markings aren't allowed in most competitive show rings.)


A dog sits on a chair and rests its chin on a table.

Those adorable "puppy eyes" aren't an inadvertent expression of canine emotion; they're a deliberate ploy to get our attention. Puppies (and their older kin) have learned that raising their eyebrows, which makes their eyes appear bigger and sadder, makes them magnets for human attention. According to one study from 2017, dogs are more likely to make dramatic facial expressions like puppy-dog eyes when they know humans are watching. And it works. Research has shown that shelter puppies who put on such faces get adopted more quickly than dogs that show other behaviors, like wagging their tails.


Two identical puppies and their mother sit in the grass.

Scientists don't know how common identical twin puppies are, because until very recently, no one was able to prove that they existed at all. In 2016, Kurt de Cramer, a South African veterinarian, noticed something unusual while performing a C-section on a pregnant Irish wolfhound. Normally, every puppy gets its own placenta, yet de Cramer noticed that two of the seven pups in this litter shared a single placenta. Testing later verified that the puppies were genetically identical. It was the first confirmed case of identical twin puppies in the world.


Three puppies sit on a cushion.
Kim et al., Scientific Reports (2017)

In 1996, Dolly the sheep became the first successful mammal clone. Nine years later, geneticists in South Korea used the same process to engineer the world's first canine clone, an Afghan hound named Snuppy. While Snuppy passed away in 2015 at the respectable age of 10, his story isn't over yet. Last November, researchers announced that four puppies had been cloned from his stem cells. Sadly, one of the pups died a few days after its birth, but the other three survived. Scientists hope that these young dogs will teach us how healthy cloned animals are compared to their naturally conceived counterparts.


Lin Manuel Miranda
Justin Sullivan, Getty Images

In the award-winning musical Hamilton, Aaron Burr and Alexander Hamilton sing a ballad called "Dear Theodosia" to their newborn children. The tender song's inspiration wasn't a newborn babe, though. Lin-Manuel Miranda wrote it the week he adopted Tobillo, a stray puppy he and his wife found while on vacation in 2011.


A black-and-white portrait of John Steinbeck
Hulton Archive/Getty Images

Of Mice and Men might feature one of the biggest animal lovers in American literature—the rabbit- and puppy-loving Lennie—but ironically, a puppy once jeopardized the novel's existence. In May 1936, John Steinbeck's Irish setter, Toby, was going through his teething phase. Left alone one night, he demolished half of his master's manuscript for Of Mice and Men, eating through two months of work. And get this—Steinbeck didn't have any backup copies. But the author found it hard to stay angry with the puppy. "I was pretty mad, but the poor little fellow may have been acting critically," he wrote. "I didn't want to ruin a good dog for a manuscript I'm not sure is good at all." He just buckled down and rewrote the shredded chapters.


A 1967 photo of the Rolling Stones strolling through a park in London
Roger Jackson, Central Press/Getty Images

While the Rolling Stones were on tour in the U.S. in 1964, a fan gave guitarist Keith Richards a collie puppy named Ratbag. When Richards returned to the UK, rather than subject the pup to quarantine, he smuggled the animal through British customs under his coat. The dog would become one of Richards's most beloved companions, and a biographer would later write that the star "appeared to identify [with Ratbag] more than anybody else."


Bo Obama sits on the White House lawn.
Obama White House, Flickr // Public Domain

In April 2009, the Obamas adopted Bo, a 6-month-old Portuguese water dog. That summer, the White House put together an official baseball card loaded with fun facts about America's First Pooch. (For one: He can't swim.) You can still download the collectible card online.


Dogs can bring out the best in people, including political adversaries. While seated next to each other at a state dinner in Vienna in the early 1960s, First Lady Jackie Kennedy and Soviet Premier Nikita Khrushchev got to chatting about Strelka, the world-famous dog who had recently been sent into low-Earth orbit by the Soviet space program. Afterward, Khrushchev sent the Kennedys one of Strelka's newly born daughters. The puppy's name was Pushinka, which means fluffy in Russian.


A Weimaraner puppy stands in an office at the Museum of Fine Arts, Boston.
Museum of Fine Arts, Boston

Boston's Museum of Fine Arts is currently training a Weimaraner pup named Riley to find unwanted pests that, if left unchecked, could harm priceless masterpieces. Riley is being taught to sniff out art-threatening insects like textile-eating moths and wood-boring beetles. "Pests are an ongoing concern for museums," deputy director Katie Getchell told The Boston Globe in January 2018. "It's exciting to think about this as a new way to address the problem." If Riley is able to do his job well, she said, other museums and archives that collect infestation-prone materials might be able to use trained dogs as a defense against bugs, too.


Guide dog puppies in training are led by their trainers.
Erik S. Lesser, Getty Images

Not all puppies have what it takes to become guide dogs. Guide dogs have to be healthy, confident, hardworking, and not easily distracted. At the end of the day, many pups just aren't cut out for this line of work—at Guiding Eyes for the Blind, a nonprofit that trains and places seeing eye dogs in New York, only about 36 percent of trainee dogs make it. That's where Watson, the IBM supercomputer famous for winning Jeopardy, comes in. IBM has developed a new program for Watson that helps it predict how likely individual puppies are to graduate from Guiding Eyes's training school using data on the temperament, medical history, and genetics of the dogs as well as the personality traits of their trainers. The organization expects to improve its guide-puppy graduation rate by 20 percent using Watson's computing power.


A poodle puppy sits on a desk next to a man working on a laptop.

That puppy portrait hanging in your cubicle at work might be a bigger asset than you realized. For a 2012 Hiroshima University experiment on productivity, participants were asked to look at pictures from one of three categories: tasty food snapshots, pictures of adult animals, or photos of puppies and kittens. Then, they were asked to play a board game that required lots of precision. As it turned out, people who'd just seen puppies and kittens had an easier time concentrating on the task at hand than study subjects who saw other types of images.


A canine jawbone
Janssens et al., Journal of Archaeological Science (2018)

In 1914, archaeologists in Germany discovered the fossilized jawbone of a puppy that lived 14,000 years ago. According to a 2018 study on the specimen, the jaw probably belonged to a 27- or 28-week-old pup—and a sick one, at that. The teeth showed signs of canine distemper virus, a life-threatening disease that still has no cure. Analysis of the bone suggested that the animal first came down with the sickness at 19 weeks old. "Without adequate care," study co-author Luc Janssens noted in a press release, "a dog with a serious case of distemper will die in less than three weeks," yet this pup survived for another eight weeks. Even though the puppy wouldn't have been very useful to its prehistoric human owners, they kept it clean, warm, and well-fed for months, helping it survive for longer than it otherwise would have.


'Puppy' stands outside the Guggenheim Museum Bilbao.

Since it opened in 1997, the Guggenheim Museum in Bilbao has been home to Puppy, a towering, flower-covered sculpture that artist Jeff Koons modeled after a young West Highland terrier. The 17-ton pooch owes its shape to a fabric-covered mesh that is topped with 37,000 live flowers. The 40-foot-tall, puppy-shaped garden is now regarded as a mascot for both the museum and the city itself.


A puppy plays with a toy at the Puppy Bowl.
Animal Planet

The fur-rocious Super Bowl spoof known as the Puppy Bowl made its debut on Animal Planet back in 2005. Viewers might be surprised to find out that unlike the real game, the Puppy Bowl isn't broadcast live. Instead, the contest is shot over the course of an entire week. The crew spends two days filming the dogs with the help of 100 or more canine wranglers. Afterward, they dedicate three more days shooting things like sponsored products and cheerleader cats. Once production finally wraps, the editing process takes three full months.


Hulton Archive/Getty Images

The first dog to play Lassie on film was really a "laddie." Specifically, he was a male Rough collie named Pal. As a pup, the dog had some behavior issues—little Pal was overly enthusiastic and drove his first owner crazy with nonstop barking. (Even more disconcerting was the puppy's habit of chasing down motorcycles, a pastime he never outgrew.) After animal trainer Henry Peck failed to make any progress with Pal, he referred the puppy's owner to a colleague by the name of Rudd Weatherwax, who was much more successful at training him. Pal's original owner eventually gave him to Weatherwax, and the rest is history. Under the trainer's guidance, Pal starred in seven Lassie movies, plus two episodes of the spinoff TV series. Decades after his passing, the Saturday Evening Post declared that Pal had enjoyed "the most spectacular canine career in film history."

iStock // Heinrich Hoffmann/Keystone Features/Getty Images // collage by Jen Pinkowski
When German Scientists Tried to Rename Bats and Shrews, Hitler Threatened to Send Them to War
iStock // Heinrich Hoffmann/Keystone Features/Getty Images // collage by Jen Pinkowski
iStock // Heinrich Hoffmann/Keystone Features/Getty Images // collage by Jen Pinkowski

In The Art of Naming (The MIT Press), Michael Ohl, a biologist at the Natural History Museum of Berlin, delves into the art, science, language, and history of taxonomy. There are some 1.8 million known species—and scientists estimate that 100 million more await discovery. Every one will need a name. How does the process work? 

Ohl takes us into the field with the explorers and scientists at the forefront of naming the natural world, including Father Armand David, a French priest who was the first to describe the panda to the Western world; American paleontologists Edward Dinker Cope and Othniel Charles Marsh, who bitterly battled in the Bone Wars; and Polish biologist Benedykt Dybowski, whose unique naming system for crustaceans called gammarids (a.k.a. "scuds") resulted in tongue-twisters such as Cancelloidokytodermogammarus (Loveninsuskytodermogammarus) loveni.

In the excerpt below, Ohl tells the story of one of the little-known footnotes to World War II: When Adolf Hitler threatened the German biologists who wanted to rename bats and shrews. And, read on for the best bat nickname of all time: "bacon mouse."

—Jen Pinkowski


On March 3, 1942, a brief item with a rather peculiar headline appeared tucked away in the Berliner Morgenpost newspaper. "Fledermaus No Longer!" the bold letters proclaimed. The following short text was printed underneath:

"At its 15th General Assembly, the German Society for Mammalogy passed a resolution to change the zoologically misleading names 'Spitzmaus' [shrew] and 'Fledermaus' [bat] to 'Spitzer' and 'Fleder.' Fleder is an old form for Flatterer [one that flutters]. The Spitzmaus, as it happens, has borne a variety of names: Spitzer [one that is pointed], Spitzlein, Spitzwicht, Spitzling. Over the course of the conference, several important lectures were held in the auditorium of the Zoologisches Museum […]."

To this day, despite the problems announced by Germany's leading specialists on mammals on the pages of one of the capital's daily papers, fledermaus and spitzmaus remain the common German names for bats and shrews. Neither dictionaries nor specialized nature guides contain entries for fleder or spitzer (provided one disregards the primary definition of spitzer, which is a "small implement used for the sharpening of pencils").

Indeed, a swift response to the item in question arrived from an unexpected source. Martin Bormann, Adolf Hitler's private secretary, sent a message on March 4, 1942, to Hans Heinrich Lammers, head of the Reich Chancellery. The missive contained remarkably unambiguous instructions from Hitler:

"In yesterday's newspapers, the Führer read an item regarding the changes of name ratified by the German Society for Mammalogy on the occasion of its 15th General Assembly. The Führer subsequently instructed me to communicate to the responsible parties, in no uncertain terms, that these changes of name are to be reversed immediately. Should members of the Society for Mammalogy have nothing more essential to the war effort or smarter to do, perhaps an extended stint in the construction battalion on the Russian front could be arranged. Should such asinine renamings occur once more, the Führer will unquestionably take appropriate measures; under no circumstance should terms that have become established over the course of many years be altered in this fashion."

There's no question that the "responsible parties" understood and responded to the injunction, which could hardly have been misinterpreted. On July 1, 1942, at least, a notice was printed in the Zoologischer Anzeiger—at that time, the "organ of the German Zoological Society"—that comprised a scant five lines. The notice has no byline and can most likely be attributed to the journal's publishers:

"Regarding the discussion [in earlier issues of the Zoologischer Anzeiger] about potential changes to the names 'Fledermaus' and 'Spitzmaus,' the Editors wish to make public that terms that have become established over the course of many years are not to be altered, following an announcement by the Reich Minister of Science, Education, and National Culture, as per the Führer's directive."

It's conceivable that Lammers forwarded Hitler's instructions (which had reached him by way of Bormann) to Bernhard Rust, the Reich Minister of Science, Education, and National Culture. Rust will then likely have ordered one of the "parties responsible" for the unpopular initiative to publish the retraction in the appropriate platform. The Zoologischer Anzeiger fit the bill, considering the fact that by 1941 it had already featured two articles debating whether the name spitzmaus should be changed.

What is the problem, though, that veteran scientists have with spitzmaus and fledermaus, those innocuous terms for the shrew and the bat? And how could it come to pass that Adolf Hitler—preoccupied as he was in 1942— should personally join in the campaign for the correct classification of these small mammals?


The common thread in these two unremarkable and familiar terms is of course the second word component, maus, or "mouse."

Fledermaus and spitzmaus … are (linguistically) first and foremost mice. By referencing certain characteristics in these compound words (fleder comes from flattern, "to flap"; spitz, or "point," refers to the shrew's pointy nose or rather head shape), it becomes possible to provide a clear name—or almost clear, at least, because there are many bat and shrew species, but more on that later.

Both names, of course, imply affiliation with mice, and that's the sticking point. In zoological terms, mice are a group of rodents known at the higher level of classification as Muroidea, "muroids" or the "mouse-like." The group includes quite the mix of animal groups, with occasionally curious names like zokor, blind mole-rat, spiny tree mouse, and Chinese pygmy dormouse, not to mention our pet hamsters and those domestic but unwelcome mice and rats. Common to all muroids are sundry and complex structural features in the skull, coupled of course with the oversized, continually growing incisors typical of rodents. Beyond that, although endless evolutionary gimmickry can revolve around this mouse theme (long or short legs, different fur colors and tail lengths, and much more), and even without biological expertise, most muroids tend to be identifiable as mice, if only vaguely.

Zoologically speaking, a mere mouse-like appearance is insufficient to denote a muroid. Instead, the specific anatomical features of the skull must be in evidence.

Field, house, and deer mice are familiar to many North Americans, although they typically live hidden away, and we don't often encounter them. These animals with the "mouse" base in their name are truly mice in the zoological sense.

The same cannot exactly be said for the bat and shrew—the fledermaus and spitzmaus—despite their names. Neither of them is even a rodent or, consequently, a muroid. Then what are they?

In the classification of mammals, a whole series of groupings is traditionally distinguished, usually assigned the rank of order within the class of mammals. Depending on scientific opinion, there are 25 to 30 of these orders of mammals. Rodents comprise one of these orders, to which muroids and several other groups of mammals belong.

Bats, meanwhile, are typical representatives of the order of flying mammals. Their scientific name is Chiroptera, from the Greek words chiros (hand) and pteros (wings). Chiroptera, then, means "hand-flier," which is a fitting name for bats and their closest relatives, flying foxes.

The systematic placement of the shrew, or spitzmaus, is determined in much the same way. They, too, fail to possess the mouse characteristics in question, although they do share traits with moles and hedgehogs, as well as with the solenodon (meaning "slotted tooth"), which is a venomous critter native exclusively to the Caribbean islands. They are now situated under the wondrous designation Eulipotyphla, but only since 1999. How they are related—along with ties to an array of other mammal families, such as tenrecs, desmans, and golden moles—has not been conclusively explained.

Experts have known for a long time—since Linnaeus's Systema Naturae at the latest—that neither bats nor shrews are related to mice, to which common parlance pays no heed. The fledermaus and spitzmaus comfortably maintain their spots in the lexicon.


One of the first mammal biologists to campaign for the standardization of German mammal names was Hermann Pohle. Born in Berlin in 1892, Pohle remained faithful to the city until his death and spent a large part of his life working at the natural history museum there. His career as a mammal biologist started early, when as a university student he worked as an unpaid hireling in the museum's famed mammal collection. Through diligence, endurance, and scientific acumen, he worked his way up to head curator of mammals. He thus held one of the most influential positions, of both national and international significance, in the field of systematic mammal research.

In 1926, Pohle—along with Ludwig Heck, the former director of the Berlin Zoo, and a number of other colleagues—founded the German Society for Mammalogy, of which he was the first head. Pohle thus had his finger on the pulse of mammal research, as it were, and he followed the history of the society over the next five decades "with keen interest," as one biographer noted.

In addition to his work as a researcher and curator of the mammal collection at Berlin's Museum für Naturkunde (Museum of Natural History), Pohle's interests also lay with German mammal names. Not only did he push for standardization of names, Pohle also campaigned to have existing names assessed for scientific plausibility and changed, should they not pass (his) zoological muster.

In 1942, Pohle published a summary article addressing the question, "How many species of mammals live in Germany?" He appended a comprehensive list of all German mammals, each with its correct "technical name," as Pohle called it, as well as its corresponding German name. When it came to the various species of spitzmaus (of which the Germans have eight, incidentally, despite the long-standing impression that there is "the" one and only shrew) and the 16 species of bats that have the base word "fledermaus" in their name, Pohle consistently uses alternative terms. The eight shrew species thus became waldspitzer, zwergspitzer, alpenspitzer, wasserspitzer, mittelspitzer, feldspitzer, gartenspitzer, and hausspitzer. For the bats, the base of their compound name was changed to fleder: teichfleder, langfußfleder, wasserfleder, and so on, all the way to a term of particular elegance, wimperfleder.

Pohle's article, which predates the society's 15th General Assembly and Hitler's emotional veto by more than a year, is a particularly interesting source because he also shares his actual motivations for the suggested changes. His emphatic objective is to see "the term 'Maus' disappear, responsible as it is for laypersons' wont to lump the animals together with actual mice."

In the estimation of these laypersons, mice are something "ugly and destructive that must be fought, or ideally exterminated." Shrews and bats, harmless as they are to humans, are thus subject to the same brutal fate. Pohle hopes for a "shift in perspective" to occur, once the endangered animals are no longer referred to as mice.

What to do, then? Pohle would prefer the term spitz for spitzmaus, but it's already been assigned to a dog breed. Rüssler could also work, only it already applies to some other insectivore. That leaves spitzer, a name that emphasizes the pointy head as a distinguishing characteristic and is still available.

Pohle wants a name for bats without "maus" but happily with a nod to the animals' flying ability. Most names of this kind are already employed for birds, and "flatterer" or "flutterer" could only logically be used for a certain population of bats, namely, those bad at flying. "Flieger" or "flyer," another hot candidate, is also in use by various other animal groups.

But why, Pohle asks the reader, would one even need to say "fledermaus," when "fleder" actually makes perfect sense? Pohle mentions that the original meaning of "fleder" was different, but few people were aware of this fact anymore.

On the off chance that he was correct in this assessment, let it be noted that fledermaus can be traced back to the 10th century, to the Old High German "vledern" or "flattern" (the infinitive form of "flatterer"). The image of the bat as a "fluttering mouse" has existed since this time in many languages, including "flittermouse" in English. A number of other German terms exist for bats. In some regions of Germany, such as Rhineland-Palatinate and Southern Hesse, the Old High German "fledarmus" is said to have been used to describe nocturnal creatures, such as moths. There, bats were apparently called "speckmaus," instead of fledermaus, because while hibernating, they could be seen hanging like pieces of bacon (speck) in the smoke.

Pohle's dedication to promoting the protection of bats and shrews through a bold name change reached its temporary culmination a year later, when—at the 15th General Assembly of the German Society for Mammalogy in Berlin—a resolution was passed on a universal and binding adoption of the spitzer- and fleder-based names Pohle had suggested. The results are known: Hitler was not amused.


We can only guess at what Hitler's actual motive was in issuing such drastic threats to prevent the name alterations proposed by the German Society for Mammalogy. It could have been his outrage that in 1942—hard times because of the war—leading German intellectuals were concerned with something so unimportant and banal as the appropriateness of animal names. Perhaps this anecdote is just a further example of Hitler's hostility toward intellectuals.

It is ultimately unclear, even, to what extent Hitler was the driving force behind this directive or whether this is a case of subordinates "working towards the Führer," as historian Ian Kershaw describes it. Conceivably, after reading the Berliner Morgenpost, Hitler may have remarked negatively regarding the zoologists' plans. His circle—in this case, Bormann—may have immediately interpreted this as "the Führer's will" and sprung to action accordingly. As for Pohle and his colleagues, it can't have mattered much whether the "invitation" to the Eastern Front came directly from Hitler or was communicated in an act of premature obedience.

Whatever the case may be, Pohle's suggested name changes did not fail because of Hitler's intervention, which presumably resonated as little with the German-speaking public as the original notice. Pohle failed because he wanted to take the basic idea of a standardized naming system out of the scientific context and transfer it into the realm of vernacular. Everyday German is not formally and officially regulated, and like every other vernacular, it follows different rules than scientific speech. It is shaped by a multitude of factors and influences that have their own unpredictable dynamic, which leads to some word usages changing while others stabilize.

In kindergarten, we learn that small, furry four-legged animals with a tail are "mice." This act of naming fulfills the exact function expected of it. It "tags" specific linguistic content—a meaning—that is generally understood. The difference between muroids and insectivores, which is important to zoologists, has no application in everyday confrontations with "mouse-like" animals and makes no difference to most people. A mouse is a mouse, whether a striped field mouse or a shrew.


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