Erin Southerland

March 7, 2023 by Erin Southerland

March Mammal Madness 2023: Learn and Win

by Patrick McShea

What chance does a giant water bug have in a battle with a wolverine? During the next few days participants in the online tournament known as March Mammal Madness will attempt to predict the outcome for this theoretical encounter plus 31 others. “Play” in this single elimination series of antagonistic animal matches begins with a wild card qualifying battle on March 13, and concludes, four well-spaced rounds of competition later, with a championship match on April 5. This now decade-old annual activity, which was created and continues to be directed by Professor Katie Hinde, of Arizona State University, has a well-earned reputation as a fun interactive educational event.

The website for March Mammal Madness (MMM) describes the proceedings as “inspired by (but in no way affiliated with or representing) the NCAA College Basketball March Madness Championship Tournament.” Like the basketball tournament, MMM relies upon a branching four-division bracket listing qualifying competitors and their ranking number to both record predictions and track the tournament’s progress. There are, of course, significant bracket differences. In place of the small print note where some sport tournament brackets announce the chart’s purpose as “For Amusement Only,” the MMM document bears the disclaimer, “MMM includes many non-mammal species.” Also, in the front and center position, where an NCAA, media sponsor, or gaming corporation’s logo would normally appear, is instead the MMM guiding motto: “If you’re learning, you’re winning!”

The clearest explanation of how the competition unfolds, and how willingness to learn is a condition of fandom, is on the MMM website:

The organizers take information about each combatant’s weaponry, armor, fight style, temperament/motivation, and any special skills/consideration and estimate a probability of the outcome and then use a random number generator to determine the outcome. This is why there are upsets in the tournament.

Another thing that can happen is if a species has to battle in an ecology that is really bad for it – for example, if a cold adapted species is battling in a tropical forest, it can dangerously overheat- changing the outcome probabilities. Sometimes an animal gets injured or snaps a canine in a previous round that carries over into the next round- just like an injury of a star player totally changes a basketball team’s outcome. Also hiding or running away counts as a forfeit.

In the early rounds the battle location is in the preferred habitat of the better-ranked combatant in the battle, and ecology can play a huge role in what happens.

I kept all of this in mind as I considered the first-round water bug versus wolverine battle. On the museum’s second floor, a giant water bug is an invertebrate detail in the Hall of Botany’s bog diorama. On the first floor, an encased wolverine taxidermy mount flanks the interactive space Discovery Basecamp. If both creatures mysteriously came to life and met on a back stairway landing, the insect would certainly be flattened or swallowed whole. Like a sports bettor double-checking a basketball team’s bench depth, foul-shooting percentage, or dependable three-point shooters, I conducted a brief internet search for wolverine vulnerabilities.

Details in a summary of the Western States Wolverine Conservation Project revealed this large member of the weasel family as a species highly sensitive to climate change. The long-clawed and densely furred carnivore, whose common name has been used by various corporations to create brands for action heroes, rugged footwear, and all-terrain vehicles, requires large territories with persistent spring snow cover. In the four U.S. states where resident populations of wolverines are known to occur (Washington, Montana, Idaho, and Montana), locations with heavy spring snow cover provide ample “refrigerated” space for the catching of prey, as well as safe denning sites for pregnant females.

I still picked the wolverine to beat the giant water bug, but I won’t be surprised if it doesn’t happen. Highways were mentioned in some research summaries as barriers to wolverine movements, raising the possibility of a forfeited match. Despite a reputation for ferocity, a no-show wolverine could send a giant water bug to the MMM second round.

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

World Pangolin Day 2023 – The Mysterious Brain Bone

by John Wible

The third Saturday in February marks World Pangolin Day, celebrating the scaly anteater that is sometimes called the pinecone mammal. Pangolins are covered with scales made of keratin, the same stuff in your fingernails and hair. Because some traditional medicines mistakenly impart curative powers to their scales, pangolins have become the most heavily illegally trafficked animal on the planet. Pangolins lack teeth and live exclusively on social insects, like ants and termites, which they catch with their very long sticky tongue. Today, there are eight species of pangolins, four in Asia and four in Africa. The fossil record reveals greater diversity and geographic distribution for these unusual creatures, including Europe and North America.

I study the evolutionary relationships of mammals, building family trees based on the anatomy of living and extinct species. In the 1800s and 1900s, pangolins were grouped with other mammals that are toothless or have very reduced teeth, such as anteaters, aardvarks, sloths, and armadillos, in the aptly named Edentata (think edentulous, or “toothless”). In the last 25 years, the study of DNA has revealed a totally different set of relationships for these edentate mammals. Aardvarks are in an African group with elephants, elephant shrews, tenrecs, and hyraxes; anteaters, sloths, and armadillos are in a South American group; and pangolins are most closely related to Carnivora (dogs, bears, cats, hyaenas, raccoon, etc.). It is hard to imagine that the gentle, toothless pangolins are close kin to the ferocious meat-eater lineage that includes lions, tigers, and saber-toothed cats.

Although DNA supports relationships of pangolins and carnivorans, we are hard pressed to find anatomical features that link the two groups. One unusual feature shared by both and, therefore, hypothesized to be present in their common ancestor is the os tentorium or brain bone! A typical mammalian brain is composed of three parts delimited by deep grooves, termed sulci, the fore-, mid-, and hindbrain, which correspond respectively to the olfactory bulbs, cerebrum, and cerebellum.

*This brain of the African white-bellied tree pangolin,* Phataginus tricuspis, is modified from Iman et al. (2018: Journal of Comparative Neurology 256: 2548-256), courtesy of Paul Bowden, Carnegie Museum of Natural History.

The human brain is dominated by its greatly enlarged cerebrum with tiny olfactory bulbs; pangolins and carnivorans have a much better sense of smell with well-developed olfactory bulbs and relatively smaller cerebrum. The brain in mammals is encased in a fluid-filled space surrounded by layers of connective tissue and within the bony braincase of the skull. One of the connective tissue layers, the dura mater, has a fold called the tentorium cerebelli (meaning the tent of the cerebellum) that fits in the deep sulcus between the cerebrum and cerebellum. In pangolins and carnivorans, the connective tissue tentorium has a layer of bone in it, creating a partial bony separation between the cerebrum and cerebellum. In pangolins and carnivorans, the os tentorium is not a single bone, but is made up of contributions from three or four skull bones. There are other mammals that independently have evolved an os tentorium, including horses, but it is not as extensive as that in pangolins and carnivorans.

*Chinese pangolin,* Manis pentadactyla, CT scan data. Top, whole cranium; middle, sagittally sectioned cranium with brain added; bottom, sagittally sectioned cranium with blue indicating os tentorium.

Okay, so we have a nice anatomical feature allying pangolins and carnivorans. However, we are left with one very large unanswered question. Why? If it is such a good thing to partially separate the cerebrum and cerebellum by bone, why don’t all mammals do it? The os tentorium is said to be “protective” of the brain, but protective how? Did a random mutation some 60 million years ago in the common ancestor of pangolins and carnivorans lead to the formation of the brain bone in the living forms? Is the brain bone somehow linked to another innovation that is strongly selected for? Is there some function to the brain bone that our brains cannot fathom? As an anatomist, I can study the structure and distribution of the brain bone in living and extinct mammals but to get at the “why” question may require a deep dive into molecular biology. Understanding the genetics behind the os tentorium may be the only path forward on cracking this mystery.

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

Echoes of Freedom in an Owl’s Call

by Pat McShea

“Is that owl real?” Students who approached the museum activity station at a “Dream STEAM” event on Martin Luther King Jr. Day repeated those four words to express curiosity about a 20-inch-high Barred Owl taxidermy mount. The setting was a large meeting room in the Bible Center Church’s Worship, Arts, Recreation, and Ministry Center in Pittsburgh’s Homewood neighborhood. Here, during a busy three-hour morning session, small groups of students ranging from kindergarten to fifth grade rotated with their adult chaperones among activities related to STEAM (Science, Technology, Engineering, Art, and Math) or Black History and Culture.

I was one of three museum representatives who brought the owl and other, less visually striking materials, to enhance an activity we hoped would spark greater interest in science as well as increase knowledge about a heroic Black figure in American History, Harriet Tubman.

Answers of “partially real” to student questions about the owl’s authenticity were provided first, as we shared information about the taxidermy mount’s glass eyes, wire-supported feet, interior foam body, but very real feathers, beak, and talons. Then came an explanation about how in 1849, Harriet Tubman’s expert knowledge of tides, seasons, weather, wildlife, plants, and the stars of the night sky enabled her to escape enslavement on a timber plantation on the Eastern Shore of Maryland, and then safely cross more than 100 miles of forest and wetlands to reach freedom in Philadelphia, Pennsylvania.

Tubman returned to Maryland multiple times during the next ten years to safely lead a total of approximately seventy people in escape from enslavement to freedom, which could sometimes only be guaranteed in places as distant as Canada. When we recounted these courageous actions for the students, the owl assumed a prominent role in our narrative. Tubman used imitations of Barred Owl calls as a code of cautionary signals to the people she physically guided. With the aid of a battery powered bird song player, the students were able to listen to the species’ distinctive barked notes, nine booming syllables that invite translation into the echoing question, “Who Cooks For You? Who Cooks For You All?”

Imitation owl calls from the students followed, spontaneous and solicited, with both types gently critiqued by a reminder that in the dark woods of 1850’s coastal Maryland or Delaware, the skill of the call’s delivery could be a matter of life or death.

The museum’s activity station also provided opportunities for students to note owl adaptations via pencil drawings, and to examine muskrat pelts as an aid in considering Harriet Tubman’s childhood labor checking traps for the rodents in the marshes of the plantation where she was enslaved. One tabletop display that drew the attention of some students and every adult chaperone credited Ranger Angela Crenshaw, currently Park Manager for Rocks, Susquehanna and Palmer State Parks in Maryland, as the source for much of the activity’s shared information.

*Harriet Tubman UGRR State Park and Visitor Center – Ranger Crenshaw with the Bust of Tubman*

A West Virginia native with strong Baltimore roots, Crenshaw presented interpretive programs for over four years as a ranger at Harriet Tubman Underground Railroad State Park and Visitor Center, a 17-arcre site in Dorchester County, Maryland. Last year, the bicentennial anniversary of Tubman’s birth, articles about the historic icon’s naturalist skills in both Audubon and Smithsonian magazines included quotes from Crenshaw. On May 14, a date Pittsburgh Mayor Ed Gainey proclaimed as “Harriet Tubman Day” in the city, Crenshaw joined seven other presenters for a two-hour panel discussion on Zoom about Tubman’s legacy organized by the Dr. Edna B. McKenzie Branch of the Association for the Study of African American Life and History.

*Harriet Tubman UGRR State Park and Visitor Center – Muskrat Exhibit – MD Department of Natural Resources*

When a presenter from another organization asked about how Ranger Crenshaw became a reliable source for information about Harriet Tubman, I recalled a published interview during which she described how her earliest days at the then new park forced a deep immersion into the landscape, and lots of reading about American Slavery, the religion of enslaved people, and the Underground Railroad. Among those documents was an 1868 biography of Tubman titled The Moses Of Her People, by Sarah Bradford, and a letter endorsing the book, by another native of Maryland’s Eastern Shore who escaped enslavement, Frederick Douglass.

Beyond the Simple Ecosystem Graphic: Teaching About Biodiversity and Pollination

by Pat McShea

You probably remember some version of this graphic: simple line drawings linked by arrows to chart energy flow through an ecosystem featuring the Sun, a patch of grass, a rabbit, and a hawk or fox. During the closing minutes of a recent day-long educator workshop about biodiversity at Carnegie Museum of Natural History, two participating middle school teachers cited the pervasive textbook illustration as an educational prop they now felt comfortable moving beyond.

Natalie Miles and Christian Shane, science teachers at North Allegheny School District’s Ingomar Middle School, expressed confidence that the seventh graders they work with would benefit from guided firsthand explorations of more complex energy flows involving various plant and invertebrate interactions. “We already teach about pollination,” explained Christian, “and with this information we can guide students on investigations right where they live.” After endorsing Christian’s comments, Natalie added a more personal note. “You’ve kept my nerdy science self fully engaged today. Thank you.”

The core experience that so captivated the pair was a carefully prepared slide presentation by museum scientist Dr. Ainsley Seago. Because the Associate Curator of Invertebrate Zoology likened her session to a sales pitch for insects, she began with what could be termed product information specific to the museum: The CMNH collection consists of approximately 16 million pinned insect specimens, representing locations all over the world, and spanning 150 years of collecting; Moths (Lepidoptera), beetles (Coleoptera), and fleas (Siphonaptera), are collection strengths, but the wide-ranging research resource also includes many groups of non-insect invertebrates.

The ubiquity of insects and the increasing ease and accuracy of their identification through hand-held technology such as the iNaturalist smartphone app were the next topics on Ainsley’s presentation agenda. Then her core material was setup by a reminder of two different but potentially connected circumstances: 1) Pollinators and bee declines are hot topics right now. 2)Teachers of some grades and subjects need to cover ecosystems according to the PA science standards.

An Antherophagus species of beetle hitches a ride to its next home by attaching to a bumble bee’s tongue. Copyright © 2016 Ilona L.

What followed was refresher session on the biomechanics of pollination that moved seamlessly into enthusiastic introductions for a cast of a dozen insect and other invertebrate characters that might visit, or even inhabit, the blossom of a common wild sunflower on a late summer or early fall day. Some creatures arrived in search of pollen or nectar, others to be in the proper place to ambush and prey upon such visitors, and the most memorable, a tiny fungus beetle whose most supportive micro-habitat is the decaying detritus within bumble bee nests, to temporarily attach itself to that insect’s tongue, and hitch a ride to a new home.

Besides offering her audience alternatives to organisms favored by many textbooks, Ainsley aptly displayed what the late Dr. John Rawlins, Curator Emeritus for the museum’s Section of Invertebrate Zoology termed “bug love.” As I watched the performance from my seat as an observer in the back of the workshop classroom, I recalled something historian David McCullough wrote about Dr. Margaret B. McFarland, the University of Pittsburgh child psychologist who was a strong influencer of Fred Rogers television programs for young audiences. “What she taught, in essence, is that attitudes aren’t taught, they’re caught. If the attitude of the teacher toward the material is positive, enthusiastic, committed, and excited, the students get that.” Such transmission of attitudes also applies to older audiences.

For information about the next scheduled educator workshop, please visit our Events page.

Groundhog Day 2023

by John Wible

January 21, 2023 was Squirrel Appreciation Day! With Groundhog Day, which commemorates our most famous squirrel, Punxsutawney Phil, right around the corner, I thought it appropriate to celebrate squirrels with this blog.

Rodents are the most diverse lineage of living mammals with more than 2,500 species, which represents nearly 40% of the species diversity of living mammals. Squirrels (Sciuridae) are one of 36 families of living rodents. There are nearly 300 species of squirrels found in the Americas, Eurasia, and Africa; a few squirrels have been introduced into Australia by humans. Broadly speaking, there are three main types of squirrels: tree, ground, and flying. Tree and ground are descriptive of their main habitats; flying squirrels also inhabit trees but are so called because of their unique locomotory pattern, which actually isn’t flying but gliding! Regarding their evolutionary relationships, all flying squirrels are more closely related to each other than to other squirrels, supporting a single origin of gliding in their common ancestor. The tree and ground squirrels do not show the same pattern; all ground squirrels are not each other’s closest relatives and the same is true of all tree squirrels. The fossil record (see text below) supports tree life as the earliest squirrel habitat, with multiple episodes of ground invasion from the trees.

In Pennsylvania, we are fortunate to have seven native species of squirrels (two ground, three tree, and two flying). You can learn more about Pennsylvania mammals at our website: https://mammals.carnegiemnh.org/pa-mammals/

Allegheny County has six of the seven PA squirrel species: the two ground squirrels (the Eastern chipmunk, Tamias striatus, and the groundhog, Marmota monax); the three tree squirrels (the gray squirrel, Sciurus carolinensis, the fox squirrel, Sciurus niger, and the red squirrel, Tamiasciurus hudsonicus); and one of the two flying squirrels (the Southern flying squirrel, Glaucomys volans). Depending on where you are in Allegheny County, you may see all six squirrels, although the Southern flying squirrel is likely the most elusive because of its nocturnal (nighttime) activities.

Squirrels have a long evolutionary history. The oldest fossils identifiable as squirrels first appeared around 34 million years ago in western North America, all showing adaptations to tree life. One of these, Protosciurus, is on display at the Smithsonian in Washington, D.C. (see below). Its skeleton is remarkably like those of living gray squirrels, both in size and morphology. Given that this remarkable similarity occurred over 30 million years of geological time, scientists consider our gray squirrel and tree-adapted relatives to be living fossils, that is, not dramatically changed compared to their very ancient relatives.

*Reconstruction of the skeleton of* Protosciurus on display at the Smithsonian’s National Museum of Natural History in Washington, D.C. *Image credit: Claire H. from New York City, USA, CC BY-SA 2.0 https://creativecommons.org/licenses/by-sa/2.0, via Wikimedia Commons*

Most rodents are small mammals; think mice and their relatives. Punxsutawney Phil is the second largest living squirrel; his cousin, the hoary marmot, Marmota caligata, from the Pacific Northwest is slightly larger, with adult males typically over 20 pounds. There was a larger ground squirrel that lived in western North America between 10 and two million years ago, Paenemarmota, a Latin name that translates to “almost a marmot.” Some of my colleagues have called it the “giant marmot,” which should be taken with a gigantic grain of salt! Below is an image of four ulnae, one of the two bones in the forearm. On the left is the living groundhog and next to it is the “giant marmot.” Anatomically, the bones are nearly identical, with one a little larger than the other. Weight estimates for the “giant marmot” are around 35 pounds. Yes, that is big for a squirrel, but not compared to some truly giant rodents. Next to the “giant marmot” is the ulna of the largest living rodent, the semiaquatic Central and South American capybara, Hydrochoerus, which translates to “water pig.” Capybaras, which can grow to nearly 150 pounds, are related to guinea pigs! But wait, there is more. Capybaras pale in comparison to the largest rodent that ever lived. The 8-million-year-old Proberomys from Venezuela was estimated to be the size of a large African antelope at 300 to 550 pounds. Yikes, now that is a giant guinea pig.

*Ulna (forearm bone) of select living and extinct rodents.*

Recently, one of my colleagues, Ornella Bertrand from the Universitat Autònoma de Barcelona, Spain, and coauthors have studied the evolution of the brain in squirrels. From CT scans of fossil skulls (see images below), they were able to recreate various parameters of the brain, including the relationship between brain size and body size. They found that squirrels living in trees had larger brains to their body size than other squirrels, that life in the complex arboreal environment was a driver of brain evolution in squirrels. The result of this evolutionary story for us may be that we will always be hard pressed to build a bird feeder that those big-brained tree squirrels can’t get into!

*Images courtesy of Ornella Bertrand. Middle, skull taken from CT scans of the 32-million-year-old fossil squirrel* Cedromus wilsoni from Wyoming with the blue indicating the reconstructed brain, shown separately to the right; left is Ornella’s reconstruction of the animal’s head. For 3D models made by Ornella Bertrand and more, see https://ornellabertrand.wordpress.com/3d-models/

John Wible, PhD, is the curator of the Section of Mammals at Carnegie Museum of Natural History.

2022 Rector Christmas Bird Count Results

by Annie Lindsay

*Red-shouldered Hawk. Image credit: Brady Karg*

On the morning of December 17, 2022, 41 birders assembled at Powdermill Avian Research Center to receive the maps and datasheets for the sectors they’d be visiting for the annual Rector Christmas Bird Count (CBC). During the CBC, participants identify and tally every bird they see or hear within a pre-established 15-mile-diameter circle on a selected day between December 14 and January 5. The Rector count was established in 1974, but the history of the CBC extends back to 1900, when a small group listed birds in 25 count circles on Christmas Day. Now sponsored by the National Audubon Society, the CBC has expanded to include nearly 3,000 circles throughout the Western Hemisphere. The CBC welcomes birders of all skill levels and is one of the largest and longest-term community science projects.

The Rector count’s center point is just northwest of Powdermill Nature Reserve, and encompasses a variety of habitats including the ridge-top forests of Chestnut Ridge, Laurel Summit State Park, Laurel Mountain State Park, and Forbes State Forest, the mountain stream valleys and hillsides of Linn Run State Park and Powdermill Nature Reserve, two lakes that often attract migrating or overwintering waterfowl, and rolling farmland interspersed with small towns. This habitat variety means that species diversity can be quite high, and since 1974, birders have tallied 131 species in the Rector circle.

Last year, warm weather extended far into the fall, and the Rector count recorded high totals of many species that we would normally expect to spend the winter a bit further south. This year, however, the fall weather was more typical of southwestern Pennsylvania, and temperatures on the day of the count hovered around freezing as large, fluffy snowflakes fell throughout the morning. The day began early as a few ambitious birders searched for owls before dawn, finding eight Eastern Screech Owls. By dawn, all participants headed to their sectors to count diurnal birds, while an additional eight birders counted what they saw and heard in their yards and visiting their feeders. As dusk fell, CBC participants met at Powdermill for a tally dinner, an evening of camaraderie and sharing stories from the day. Although the species total was only 59, which is slightly below average, individual numbers for each of these species were typical. A few, including Wild Turkey, Bald Eagle, Red-shouldered Hawk, Winter Wren, and Eastern Bluebird even saw new high-count records.

*Red-headed Woodpecker. Image credit: Tom Kuehl*

For the fifth year in a row, participants found Red-headed Woodpeckers during the count. This species is difficult to find in southwestern Pennsylvania, and the Rector count circle is one of the only reliable places to encounter them. A favorite of birders, this bold, color-block-patterned woodpecker always delights those lucky enough to spot one.

One of the most exciting sightings of this year’s count, and the last bird encountered for the day, was a Northern Saw-whet Owl spotted near Powdermill’s nature center just as the tally dinner ended. Northern Saw-whet Owls are found in southwestern Pennsylvania primarily during fall migration, but some overwinter here, and there is evidence that a few pairs may breed locally. Saw-whets are small and do not vocalize as readily as most of the other owls, which make them difficult to find. This fall, Powdermill’s ornithologists caught and banded 99 of these tiny owls, nearly a high fall record! As the 2022 Christmas Bird Count season wraps up, we’re already looking forward to 2023. Thank you to all participants for spending the day searching every corner of the count circle looking for birds, and to all landowners for granting participants access to their properties for a much more thorough and complete count.

March Mammal Madness 2023: Learn and Win

by Patrick McShea

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World Pangolin Day 2023 – The Mysterious Brain Bone

by John Wible

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Echoes of Freedom in an Owl’s Call

by Pat McShea

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Beyond the Simple Ecosystem Graphic: Teaching About Biodiversity and Pollination

by Pat McShea

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Groundhog Day 2023

by John Wible

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2022 Rector Christmas Bird Count Results

by Annie Lindsay

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