mammals

August 9, 2024 by Erin Southerland

What’s in a Name? The History of the Naming of the Eastern Mole

by John Wible

In the tenth edition of the “Systema Naturae” (1758), the Swedish botanist and natural historian Carl Linnaeus recognized eight orders of mammals, all of which include species that today are not particularly closely related. His order Bestiae included pigs, armadillos, hedgehogs, moles, shrews, and opossums. Of these, the hedgehogs, moles, and shrews are considered today to form a natural group, with the others coming from very far-flung branches of the mammal tree of life.

For the shrews, Linnaeus named three species of Sorex, Sorex araneus, Sorex cristatus, and Sorex aquaticus, with their habitats Europe, Pennsylvania, and America, respectively. Sorex araneus is recognized today as the common shrew (see image), distributed in Great Britain, much of the European continent, and far into Russia. However, the other two are not shrews, but are moles! Today, we recognize these as the star-nosed mole, Condylura cristata, and the Eastern mole, Scalopus aquaticus (see image). The former has a broad distribution in Pennsylvania with the latter only in the eastern part of the state.

common shrew and a worm — *Common shrew,* Sorex araneus. Photo credit: Soricida, CC BY-SA 3.0, via Wikimedia Commons

close-up of an eastern mole — *Eastern mole,* Scalopus aquaticus. Photo credit: Kenneth Catania, Vanderbilt University, CC BY-SA 3.0, via Wikimedia Commons

Just before the shrews in the tenth edition, Linnaeus named two species of moles, Talpa europaea and Talpa asiatica, with their habitats Europe and Siberia, respectively. Given the remarkable similarity in body form between the Old World and New World moles, it is surprising that Linnaeus did not recognize these four species (Sorex cristatus, Sorex aquaticus, Talpa europaea, and Talpa asiatica) as closely related.

Regarding the Eastern mole, subsequent nineteenth century authors realized Sorex aquaticus did not belong in the shrew genus Sorex. However, it was bounced around between several mole genera, including Talpa, and it was not until 1905 that the Latin binomial we use today, Scalopus aquaticus, was first used, 147 years after Linnaeus! The formal naming of species is not static, but evolves over time as we discover more about our natural world that causes us to reconsider and reevaluate past practices. Changing the shrew aspect of the common name lagged behind the formal one, as it was not for quite some time that the shrew moniker imparted by Linnaeus disappeared. A halfway point is in the famous 1846 “The Viviparous Quadrupeds of North America” by John J. Audubon and Reverend John Bachman, where they called it the common American shrew mole.

From the short text in the “Systema Naturae” where Linnaeus named Sorex aquaticus, his motivation for identifying the Eastern mole as a shrew is unclear. Equally or perhaps more enigmatic is his motivation for using the specific name aquaticus. A direct translation of Sorex aquaticus is “water shrew,” with the strong implication that this mammal lived in the water or at least spent considerable time in the water. However, Linnaeus did not travel to America and so never saw Sorex aquaticus in the wild. The Eastern mole is a fossorial (burrowing) animal that spends most of its life underground with enormous forepaws for digging. Skin covers its tiny eyes, although it does perceive light and dark, and it lacks an external ear. Maybe its enlarged forepaws were viewed as flipper-like by Linnaeus. Yet, these paws resemble those of the Old World Talpa named by Linnaeus as true moles. In 1936, mammalogist A.V. Arlton stated, “The term “aquaticus,” as applied to our common species refers to the webbed hind feet, which indicated to some early writers a possible use in swimming” (Journal of Mammalogy, 17, p. 355). Unfortunately, Arlton did not name names for these early writers! Consequently, his statement cannot be fact checked. The bottom line is that in his description of Sorex aquaticus, Linnaeus did not mention webbing for either the fore- or hind feet. And ultimately, as the namer of the species, it is Linnaeus’ motivation that we need to know.

There are some general rules for naming new species. For example, you can’t name a new species after yourself. In the Linnean era, the general trend was to apply Latin or Greek descriptors that would capture some aspect of the organism in question, a tradition continued today by most authors. For instance, our species, Homo sapiens, was named by Linnaeus and it translates to “wise man.” While we might debate the appropriateness of that as the binomial for our species, there is no debate that Sorex aquaticus is inappropriate for our ground dwelling Eastern mole.

John Wible is Curator of Mammals at Carnegie Museum of Natural History.

Scientific Names Matter in March Mammal Madness

by Erin Southerland

March Mammal Madness (MMM) bracket advice: look up the scientific names of species on the MMM website before you make your predictions. While MMM can be silly and ridiculous, it is an educational tool and the details matter. Let’s explore why by looking at the Pitcher Plant (7) vs. Northern Short-tailed Shrew (10) match.

Pitcher plant isn’t a specific species of plant, rather it describes plants with a modified leaf that resembles and acts like a pitfall trap.

Nepenthes rajah, a species of pitcher plant. © Thibaud Aronson, (CC BY-SA)

Bonnie Isaac, Collection Manager of Botany, says:

Generally, when we use the term pitcher plant, we are referring to a member of either Sarraceniaceae or Nepenthaceae. Both pitcher plant families evolved in areas where essential nutrients for plants are lacking. They needed to find a way to get their nutrients by other means. Enter carnivory.

Pitcher plants in both families primarily eat insects, but they are generalists that will catch and digest anything that comes along. However, one of these families is more likely than the other to be able to digest the Northern Short-tailed Shrew.

Bonnie tells us:

Sarraceniaceae are normally ground dwelling plants with trumpet-shaped leaves that are used to capture their prey. Many of these pitcher plants have hairs on the inside of the tube that point downward to keep the prey from crawling out. They may also have clear areas near the top of the tube to attract insects.

Members of Nepenthaceae are tropical plants that frequently have a climbing stem. The modified pitcher leaves on these plants are normally of two types: one grows up in the trees that support the vine, the other grows near the ground. The trap leaves near the ground are normally larger than the aerial trap leaves and can digest larger prey. With two types of traps these plants are opportunists and ready to capture whatever may happen into the traps.

The pitchers of Sarraceniaceae are normally not large enough to hold a Northern Short-tailed Shrew. Nepenthes on the other hand has pitchers that are large enough to hold shrews. Some Nepenthes species attract rodents by giving them a reward. The rodent in turn gives the plant nutrients either by defecating into the toilet-shaped leaf or by falling into the pitcher and being digested. Species of Nepenthes are known to trap and digest vertebrates, including rats and mice. If by chance a Northern Short-tailed Shrew happened upon a Nepenthes and fell into the trap the shrew wouldn’t stand a chance.

Since the species of pitcher plant selected for March Mammal Madness is Nepenthes rajah, it has a chance to beat the Northern Short-tailed Shrew (Blarina brevicauda).

*Short-tailed Shrew (*Blarina brevicauda)

Sue McLaren, Collection Manager of Mammals, also notes that either competitor has a chance (it is March Mammal Madness, after all):

When I think of the short-tailed shrew, I think of a fierce temperament when confronted by something dangerous. They are good climbers (I’ve seen them climb a tree trunk to a point at least eight feet off the ground). Even though their claws seem a little puny, they are more fossorial (adapted for digging and burrowing) than any other shrew so they can dig their way through densely compacted leaves and easily move through some types of soil (probably not heavy clay). Finally, they have salivary glands that produce a toxin that can subdue prey that are larger than themselves – salamanders, frogs, mice, and even birds! However, their climbing ability is probably their best defensive from inside a pitcher plant.

Anything could happen in this sure-to-be-exciting match! But if the pitcher plant was from the family Sarraceniaceae it wouldn’t be nearly as exciting.

Want to play March Mammal Madness?

Get started with these links:

Get your bracket

Look up the Latin binomials

Learn how to play

Fill out your bracket by March 10, 2024 to play this year. The competition kicks off March 11 with the Wild Card: Rainbow Grasshopper (Dactylotum bicolor) vs. Sparklemuffin Peacock Spider (Maratus jactatus).

Erin Southerland is Communications and Social Media Manager at Carnegie Museum of Natural History.

World Pangolin Day 2024 – The Mysterious Mammalian “Wishbone”

by John Wible

World Pangolin Day 2024 is on February 17, a day to raise awareness of pangolins or scaly anteaters, one of the most unique and endangered mammals on Earth. Their scales are harvested for traditional medicines that see them as cure-alls, but their scales are made of keratin like your fingernails and hair. Their scales are as medicinally effective as biting your nails.

Although I will get to pangolins, I am starting with our feathered avian friends. Birds have a Y-shaped bone in their chest called a furcula (Latin for little fork). It is part of the flight apparatus and is thought to be formed by the fusion of the right and left clavicles (our collarbones). However, some researchers think it might be a different bone called the interclavicle, which in mammals is only found in monotremes, the egg-laying mammals. Some non-avian dinosaurs have a furcula, which is part of the evidence placing them on the bird family tree. The furcula is commonly called the wishbone because of the practice of making a wish on the bone! You grab one arm and someone else grabs the other; both make wishes and then pull; whoever gets the larger piece will have their wish come true.

Chicken furcula. Photo credit: Clyde Robinson/Flickr Creative Commons

In celebration of World Pangolin Day, I want to introduce you to a mammal “wishbone.” If you search through the mammalian literature, you will not encounter a bone identified as a wishbone. Nevertheless, a small, select group of mammals have a pair of bones that looks, to me anyway, like a furcula. Here is an example.

*Lower jaw of the northern tamandua,* Tamandua mexicana. American Museum of Natural History 23437 made from CT scan data by Hannah Barton, University of Pittsburgh.

The lower jaw, the mandible, is made up of right and left bones called dentaries. They meet on the midline at the chin. In humans, the right and left bones are filled with teeth, fused on the midline, and don’t look like a furcula! The northern tamandua from Central America differs in that there are no teeth, the right and left bones are held together only by soft tissues, and it looks like a furcula! How does the tamandua survive without teeth? Tamanduas are social insect feeders (ants and termites) that swallow their prey whole; tamandua parents don’t have to worry about their kids chewing with their mouths open. Now, although the tamandua lower jaw looks kind of like a wishbone, when pulled apart there won’t be a winner as the split will be down the middle with the two halves the same size.

The vast majority of the 6,500 species of living mammals have teeth; some have dentaries fused like humans and some have them unfused like the tamandua. Of the 6,500 species, there are 31 that are toothless as their normal condition. These 31 fall into two camps: 15 are baleen whales, including the Earth’s largest animal, the blue whale, which are filter feeders; and 16 are social insect feeders like the tamandua. However, all 31 have a mandible that is reminiscent of an avian wishbone. The 16 social insect feeders are from three unrelated lineages that have convergently adapted to eating ants and termites. The three lineages are:

Spiny anteaters or echidnas (monotremes) found in Australia and New Guinea (four species).
True anteaters (myrmecophagids) found in South and Central America (four species including two kinds of tamandua).
Pangolins (pholidotans) found in Africa and Asia (eight species).

The mandibles of the #1 and #2 look like that of the northern tamandua. The left and right sides are not fused and the mandible is skinny in the front and larger in the back where it articulates with the skull. #3, the pangolins, are really different. The left and right sides are fused at the midline and the mandible is larger at the front.

*Lower jaw of the Sunda pangolin,* Manis javanica, United States National Museum 144418 made from CT scan data by the author.

*Skull of the Sunda pangolin,* Manis javanica, United States National Museum 144418 made from CT scan data by the author. Red arrow points to the two bony mandibular prongs in the close-up.

The other very odd thing about the pangolin mandible is that it has a pair of bony prongs at the front that look somewhat like teeth (red arrow). Doran and Allbrook (1973: Journal of Mammalogy) dissected the pangolin tongue and reported that the lower lip was attached to these prongs, but they did not illustrate this or explain it further. Pangolins are clearly doing something different with their mandible than the tamanduas and echindas are, but what, I don’t know. Whatever it is, it has been around in pangolins for at least 35 million years! There was a pangolin that lived in the American West during the late Eocene named Patriomanis americana and it has a set of mandibular prongs just like those in the Sunda pangolin shown here. The other difference with the pangolin mandible is that when subjected to a wishbone pull, it might not break down the middle and be more like a furcula.

I have left the baleen whales until the end. Are their mandibles more like the tamandua, the pangolin, or neither?

*Mandible of the blue whale,* Balaenoptera musculus. Only the left dentary is on display in the Hall of North American Wildlife at Carnegie Museum of Natural History. The author manipulated the photograph to create the world’s largest “wishbone.”

Baleen whales are more like the tamandua with the right and left sides unfused and the mandible larger in the back than the front. If you were able to do the wishbone pull on the blue whale, there would be no winner and someone would likely lose by throwing their back out!

John Wible is Curator of Mammals at Carnegie Museum of Natural History.

Groundhog Day 2024: Punxsutawney Phil’s Alpine Cousin

by Suzanne McLaren and John Wible

Beginning in 1887 in Punxsutawney, Pennsylvania, the celebration of Groundhog Day has made the groundhog (Marmota monax) a familiar animal to people who live far beyond the range of this species. While this large ground squirrel may get the most publicity, especially on February 2^nd every year, there are twelve related species that live elsewhere in North America, Europe, and Asia. In Europe, the Alpine marmot (Marmota marmota), which lives in mountainous areas of the continent’s central and western regions, is particularly well-known. Like the groundhog, it spends most of the year fattening up so that it can survive the winter months by hibernating.

two alpine marmots — *Credit: Sylvouille at French Wikipedia. – Transferred from fr.wikipedia to Commons., CC BY-SA 1.0*

While our local groundhog leads a more solitary existence, the Alpine marmot lives in a communal setting that includes a single breeding pair and around 15-20 of their offspring. They live in underground burrows that are passed down for generations within the family group, expanding over time into complex systems of tunnels. The tunnels eventually lead to a large chamber or den, where the entire family hibernates during the winter months. This concentrates body heat among the group and helps younger individuals to survive. Similar to prairie dogs, family members are friendly and playful with each other, grooming and touching noses when they greet. One individual, serving as a guard at the mouth of the burrow, will give off a loud whistle, to warn the rest of the family about the approach of an enemy – either a predator or even a non-family member of its own species.

Humans have hunted this species for hundreds of years for its meat. They are still hunted by the thousands for sport in Switzerland and Austria, with the large, ever-growing, yellowish-orange upper incisors sometimes displayed on hunters’ belts.

alpine marmot skull — *Picture of Alpine marmot skull showing large incisors, Klaus Rassinger und Gerhard Cammerer, Museum Wiesbaden, CC BY-SA 3.0, via Wikimedia Commons*

It is also reported that rendered Alpine marmot fat is still sought after as a folk remedy for arthritis. It is not taken internally but rubbed on sore joints.

two glass containers of rendered marmot fat — *Picture of rendered marmot fat. Credit: H. Zell, CC BY-SA 3.0*

Perhaps the most surprising anecdote about the interaction of humans and the Alpine marmot is the use of the animal for entertainment, though not for weather forecasting like Punxsutawney Phil. Stories of a trained Alpine marmot on a leash, accompanying a “hurdy-gurdy man”, somewhat like the organ grinder and his monkey, date to at least the mid-1700s as evidenced by François Hubert Drouais’ painting Les Enfants d’ Ilustre Naissance. Here, two boys sit together, one playing the hurdy-gurdy, a stringed instrument, and the other holding a dancing marmot on a leash. The traveling entertainer carried his marmot from town to town in a box. If you’ve ever witnessed the belligerent behavior of a local groundhog you might find it hard to believe that any Pennsylvania groundhog, other than Punxsutawney Phil, would allow itself to be led around on a leash or kept in a box!

picture of the painting "The Children of the Duc de Bouillion" by Francois-Hubert Drouais — Credit: François-Hubert Drouais, Public domain PD-US, via Wikimedia Commons

Suzanne McLaren is Collection Manager of Mammals and John Wible is Curator of Mammals at Carnegie Museum of Natural History.

The Nose that “Sees”

by Lisa Miriello

Despite the common name of the star-nosed mole (Condylura cristata), the 22 fleshy appendages at the end of its snout act more like an eye than a nose. These unique tentacles, or rays, are covered with more than 25,000 Eimer’s organs that hold over 100,000 nerve fibers (more than five times the number in the human hand) and are the most sensitive touch organs of any known mammal.

Given the mole’s poorly developed eyesight, the rays are far more useful for finding prey.

They are constantly moving and touching to identify what’s good to eat and what isn’t. Sensitive whiskers on the head and front feet also act as “feelers,” whether looking for food or navigating their way through dark underground tunnels.

close-up of the nose of a star-nosed mole — *“mole-star-nosed-4” by Brandon Motz is licensed under CC BY 2.0*

Found throughout much of eastern North America in low elevation areas with moist soils, star-nosed moles are one of three mole species found in Pennsylvania. Their preferred habitat consists of wetlands near streams, lakes, and swamps. The soft moist soil makes it easier to construct tunnels and underground chambers, and the mole’s short neck, powerful shoulders, and heavy claws make them efficient diggers. Shallow tunnels, often temporary, are used for traveling and foraging, while deeper, more permanent tunnels are used for resting, nesting, and escaping cold weather. Condylura is relatively safe from predators while underground but vulnerable to birds of prey, weasels, skunks, foxes, and snakes when out of their tunnels.

The star-nosed mole is a voracious eater that consumes 50% or more of its body weight each day. More notably, it holds a Guinness World Record for the fastest eating mammal.

Scientific studies have shown that Condylura can identify and eat prey in less than one-fifth of a second (200 milliseconds). That’s as many as five prey items per second, too fast for the human eye to follow.

Besides the worms, grubs, beetles, and other invertebrates found underground or on the surface, being near water gives them access to another hunting ground where they can find mollusks, aquatic insects, amphibians, and even small fish.

*“star-nosed-mole-3” by gordonramsaysubmissions is licensed under CC BY 2.0*.

Most moles can swim, but the star-nosed mole is the most aquatic of North American moles.

Their dense waterproof coat and large paddle-like limbs make them well suited for swimming and diving. They’ve evolved to have twice the lung capacity of other moles, and their long tail, almost one-third the length of its body, acts as a rudder. More time is spent foraging in the water than on land, and they’ve been seen swimming under the ice in winter. This remarkable mole can even smell under water by blowing bubbles, then inhaling the same bubbles to capture the scent molecules inside.

Not a great deal is known about the reproductive cycle of star-nosed moles. They’re more social than other moles, living in small colonies, and it’s believed that mating pairs stay together through the winter. Breeding season starts in early spring and the female produces only one litter a year, unless the first litter is unsuccessful. After a 45-day gestation period, two to seven pups are born in May and June. The newborns are blind and hairless with their tentacles folded against their snout. About two weeks later the eyes open and the tentacles unfurl and begin to function. The young develop rapidly and leave the nest after about four weeks, reaching full maturity at 10 months. The exact lifespan of this species is unknown but estimated to be 3-4 years in the wild.

“Baby star-nosed moles” by Hillbraith is Public Domain.

The extraordinary star-nosed mole stands out from other moles in many ways, and is certainly among the most unusual mammals in Pennsylvania. They’re not rare, but they’re not commonly seen even though they spend more time above ground than other moles. They’re active day and night, all year round, so keep your eyes peeled when you’re around water and if you’re lucky you might catch a glimpse of one.

Lisa Miriello is the Scientific Preparator for the Section of Mammals.

Wolverine: Status Check For a Tournament Champion

by Pat McShea

*A wolverine taxidermy mount is a popular display in Discovery Basecamp.*

Technology has revolutionized the work of wildlife biologists, but among those who study wolverines, long waits for field-collected information about these large members of the weasel family still occur. Because wolverines are known to patrol enormous home ranges, Cory Mosby, Furbearer Staff Biologist with Idaho’s Department of Fish and Game, relies upon strategically placed camera traps as effective monitoring tools. As he explained in a recent Zoom interview from his office in Boise, deep snow at high elevations can delay the retrieval of video and photographic evidence for months. “There’s a few places we placed cameras for over-the-winter wolverine studies where we weren’t able to retrieve the devices until July.”

Our discussion of wolverine research occurred just after the species received accolades as the 2023 champion of March Mammal Madness (MMM), the wide-reaching, ten-year-old educational project that masquerades as a tournament mimicking competition, but is in no way affiliated with, the NCAA college basketball tournament. The online event, founded and directed by Professor Katie Hinde of Arizona State University, challenges participants to predict outcomes for a widely branched bracket’s worth of hypothetical combative wildlife encounters. Reference material links on the MMM website encourage fans to make informed decisions, and as the tournament’s hypothetical encounters unfold, additional information about the combatants is shared via timely narrative reports.

This year, any MMM fan who tracked the wolverine’s six victory championship campaign undoubtedly learned lots of information about this carnivore with solitary ways, a bone-crushing bite, and a fierceness sufficient to intimidate even bears and wolves.

On Zoom, much of Mosby’s information sharing focused on historic wolverine distribution. He explained how, by the 1930s, a species once found across much of the American West and even in sections of several Great Lakes states, was largely extirpated in the lower 48 states by predator control programs, landscape alteration, and unregulated hunting and trapping. However, during the nearly eight decades since, changes in public policies and attitudes eventually created conditions that enabled animals from western Canada to naturally re-colonize portions of four states – north-central Washington, northern and central Idaho, western Montana, and northwestern Wyoming.

In 2010, a proposed listing of these animals under the Federal Endangered Species Act prompted the establishment of the Western States Wolverine Conservation Project, a multi-year investigation in which essential early work, beginning in 2016, involved establishing baseline information about the numbers and movements of the animals under study.

*Cory Mosby placing a camera trap as part of wolverine monitoring effort in Idaho’s Centennial Mountains.*

When presented with the question, “What do you wish the public knew about wolverines?” Mosby had a ready answer. “This might not align with popular opinion, but I wish more people realized that, as a species, at the moment, wolverines are quite secure. In Idaho today, wolverines occupy all available habitat. The population in the western U.S., the animals I’ve helped study, are on this continent, a southerly extension of a species found around the globe at northerly latitudes in suitable habitat. ‘Holarctic’ is the term that summarizes this enormous distribution.”

Mosby cites a warming climate as a big concern for wolverine populations in southernly latitudes, explaining how the same deep snow deposits that delay camera retrieval in project studies also allow female wolverines to catch sufficient kills as food for kits too young to forage on their own.

The wildlife biologist’s overall advice is to pay attention to both the local situation and the big picture. His career track, he relates, was influenced by the sudden realization of how small forces influence big systems. “I was a pre-med major at the University of Missouri taking lots of biology classes, and in one of them a visiting lecturer gave a presentation about how northern flying squirrels influence the health of entire forests by distributing spores as they feed on fungi. I realized then I wanted to work studying wildlife.”

Patrick McShea is an Educator at Carnegie Museum of Natural History.

What’s in a Name? The History of the Naming of the Eastern Mole

by John Wible

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Carnegie Museum of Natural History Blog Citation Information

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Scientific Names Matter in March Mammal Madness

Want to play March Mammal Madness?

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World Pangolin Day 2024 – The Mysterious Mammalian “Wishbone”

by John Wible

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Groundhog Day 2024: Punxsutawney Phil’s Alpine Cousin

by Suzanne McLaren and John Wible

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The Nose that “Sees”

by Lisa Miriello

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Wolverine: Status Check For a Tournament Champion

by Pat McShea

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