Enjoy the Museum from Home via our Blog

Can't make it to the museum in person? We've done our best to help cultivate resources for you to enjoy from home. Activities for the whole family, different ways to experience our exhibitions and more are included in these blogs.

March 25, 2021 by wpengine

Carnegie’s Cactus: Carnegie gigantea

by Patrick McShea

Diplodocus carnegii, a sauropod star of Dinosaurs in Their Time, is not the only large organism exhibited at Carnegie Museum of Natural History that bears the founder’s name. Within the Hall of Botany, the tree-sized saguaro cactus whose prickly form visually anchors the Sonoran Desert diorama is a species know to science as Carnegie gigantea.

Carnegie gigantea — A blooming saguaro in a diorama depicting the Sonoran Desert of southern Arizona.

The name honors Andrew Carnegie’s support, through the Carnegie Institution, for the 1903 establishment of the Desert Botanical Laboratory in Tucson, Arizona. This groundbreaking research facility, which enabled long-term studies of desert plant adaptations, was sold to the U.S. Forest Service in 1940, and later was purchased by the University of Arizona in 1956.

Today the facility is known simply as the Desert Laboratory, and visitors to its website find an immediate reference to its location on Tumamoc Hill, a site of cultural and spiritual significance to the Tohono O’odham and other Native peoples. A mission statement follows, clarifying the expanded scope of the Laboratory’s work:

The role of the Desert Laboratory is to build on the complementary strengths of culture, science, and community rooted at Tumamoc Hill and the larger Sonoran Desert to become an integrative hub of novel research, education, and outreach about how linked human and natural systems face the future of life in the desert.

Ongoing studies of the Desert Laboratory’s 5,800 saguaros fit perfectly into this mission because of the plant’s importance to the region’s Native peoples for thousands of years.

A carving depicting the saguaro harvest.

In Pittsburgh, museum visitors can learn something about the ancient connection between people and the iconic cactus by following a Hall of Botany stop with one in the Alcoa Foundation Hall of American Indians. Here, near the middle of the exhibition’s central corridor, a series of displays exploring use of plants by Native peoples includes a carving by artist Danny Flores (Tohono O’odham) that depicts the traditional harvest of saguaro fruit by Tohono O’odham women.

Consider the walk between the blooming life-sized saguaro in the Sonoran Desert diorama and the tiny carved replica to represent a spring-into-summer transition when white cactus blossoms, pollinated by bird, bat, or insect, transform into ripening red fruit.

A text panel near the model explains how gathered fruit is boiled to create a syrup which is then fermented into wine used in rituals invoking the summer rains to begin. The label also identifies the source of the specialized harvesting tool, an implement as long as a saguaro is tall. The pole is a saguaro rib, a part of the wood skeleton that once helped to hold a massive cactus upright.

Patrick McShea works in the Education and Visitor Experience department of Carnegie Museum of Natural History. Museum employees are encouraged to blog about their unique experiences and knowledge gained from working at the museum.

Groundhog Architecture

drawing of a groundhog standing out an opening of a tunnel with tunnel illustrated underground

Contrary to the pervasive myth that is revived for public amusement every February 2, groundhogs are not able to predict the approach of an early spring. If these large members of the squirrel family possess a notable skill, it’s in the field of excavation. The image above was created to provide a hint of the remarkable subterranean earthworks groundhogs construct in suitable habitat.

For the species known scientifically as Marmota monax, and whose common names include woodchuck and whistle pig, burrow digging is a solo effort. For a greater part of the year, burrow occupancy is limited to one groundhog per unit. Exceptions occur when males visit the burrows of females during a late winter breeding season, and consequently, following a 32-day gestation period, when females give birth to four to six kits. After approximately a dozen weeks of rapid development, these young disperse from their maternal burrow to dig their own lodging.

Groundhogs excavate a complex, multi-chambered burrow system in which the total length of tunnels can measure up to 65 feet. When digging a burrow groundhogs use their powerful short front legs, which are tipped with sturdy claws, to loosen soil and rocks. Loosened materials are then moved, by mouth, and deposited on the surface at the main entrance. The groundhog depicted in the illustration is standing on a distinctive subsoil-covered mound of excavated material. In a research study where several entrance mounds were removed and their soil and rock contents weighed, the average weight of these animal-built features was 275 pounds.

Typically, burrows include as many as four additional entrances, all unmarked by tell-tale signs of soil disturbance because groundhogs excavate these features from below the surface. Although the ankle-turning potential of these hidden holes is enough for some people to regret having groundhogs as neighbors, there are under-appreciated benefits to tolerating some patches of burrow-riddled property. On the coldest winter days and nights, the upper portions of groundhog burrows provide shelter to other forms of wildlife while the burrow’s owner, curled in a grass-lined chamber, remains suspended in a hibernation state a few feet below. Cottontail rabbits, for example are common squatters.

Teaching About Trees

Joe Stavish doesn’t need any reflection time to summarize the impact of the COVID-19 pandemic on his work. “The new challenge to me as an outdoor educator is working with students who are watching a screen.” The Associate Director for Community Education at Tree Pittsburgh laments months spent planning and presenting programs in which students never have the opportunity to get their hands dirty. “If you’re limited to showing pictures,” he explains, “the wow factor just isn’t there.”

Joe Stavish holding a hickory leaf in pre-pandemic times.

Tree Pittsburgh is a 15-year-old non-profit organization dedicated to the restoration and protection of our region’s urban forest through tree planting and care, education, advocacy, and land conservation. Joe’s role, in the eight years he’s worked for Tree Pittsburgh, is to make sure the organization’s contact with communities it serves are as broad as possible. He kids about “cradle-to-the-grave” points of contact before listing near parallel audience segments, K-12 school classes, scout groups, youth groups, university students, neighborhood groups, adult classes, and garden clubs.

Some of the presentations he is involved with are part of formal programs, such as One Tree Per Child, a school-focused tree-planting initiative, or Explorer’s Guide, a collaborative effort with Pittsburgh’s Park Rangers for 4^th and 5^th grades that is scheduled to soon expand beyond its initial test audience in the City’s Northside neighborhoods. Other programs can currently be described as situational. “Teachers have been eager to have any type of virtual program we want to present.” Joe concedes in recognition of the ongoing and widespread problems with remote learning.

Although Joe is concerned about the limits of screen learning, I found the videos he directed me to on an Explorer’s Guide website to be very well done. Since 2018 Tree Pittsburgh has been headquartered in a riverside campus in Lawrenceville spacious enough to include what is termed a Heritage Tree Nursery. Much of a short video titled, The Life Cycle of a Tree, was shot in the nursery, a facility at the forefront of urban forestry. I never cried “Wow” while I watched the segment, but I learned a lot.

Winging It: Quetzalcoatlus and the History of Aviation

When I see Quetzalcoatlus northropi soaring above the Cretaceous in Dinosaurs in Their Time, I’m often reminded of the Spirit of St. Louis suspended aloft at the Smithsonian National Air and Space Museum. It might sound strange that a pterosaur from 70 million years ago would bring to mind an icon of twentieth century flight, but Q. northropi is a perfect starting point for exploring modern aviation history and the interconnections between nature and aeronautical engineering.

The Spirit of St. Louis in the Smithsonian, Washington, D.C.

When I was first introduced to Q. northropi, I knew it was named after the Mesoamerican feathered serpent god Quetzalcoatl, but I assumed the northropi part came from the name of the paleontologist who discovered the great pterosaur’s remains. I soon found to my surprise that the specific name northropi was bestowed in honor of Jack Northrop, the aeronautical engineer who experimented with flying wing aircraft designs in the 1940s. When the pterosaur was discovered in Big Bend National Park in the early 1970s by graduate student Douglas A. Lawson from the University of Texas at Austin, Lawson and his advisor were struck by its size (adults could grow as large as a giraffe), wingspan (up to 36 feet), and its lack of a tail. The last of these three features made Northrop a natural namesake for the species. As the fantastic news of Quetzalcoatlus spread in 1975, the journal Science unveiled one of its most memorable cover pages: depicted on the cover of its mid-March issue to dramatic effect is a Northrop flying wing aircraft (think the grandfather of the Stealth bomber), Quetzalcoatlus, a Pteranodon (with a puny wingspan of only 18 feet), and a condor (looking like a harmless sparrow in comparison). From the moment of its discovery in Far West Texas, Quetzalcoatlus northropi captured the imagination of both the paleontological and aviation communities and does so to this day.

The tailless design of Northrop’s flying wing allowed for better fuel efficiency and increased aerodynamics compared to traditional airplane designs. Debate, however, has raged over whether or not Quetzalcoatlus’s anatomy allowed the creature its own advantage in flight…or if it could fly at all. The jury is still out on the particulars of Q. northropi’s flying ability. Recent theorizing, from the mind of paleontologist Michael Habib, has the pterosaur capable of perhaps short flights powered by quadrupedal take-off as opposed to bipedal take-off, the method used by birds. Regardless of the debate, Q. northropi has itself inspired experimentation in drone technology. In 1985, at the behest of the Smithsonian, engineer Paul MacCready and a team of fellow scientists built and tested an orthocopter modeled after Quetzalcoalus with a modified wingspan of 18 feet. While the project was not without its technical hiccups, the team successfully test-flew their human-constructed pterosaur over Death Valley that year. This drone, called QN, is now housed at the Smithsonian National Air and Space Museum and remains an ambitious and fascinating example of how scientists attempt to fathom the biomechanics of extinct species. With this in mind, maybe it isn’t so strange that I’ve imagined Quetzalcoatlus and the Spirit of St. Louis in the same thought after all.

Comparison of *Q. northropi* with a similar plane to the *Spirit of St. Louis*, the Cessna 172

While Q. northropi’s flying skills remain ambiguous, its namesake’s design is indeed found directly in nature. Northrop’s flying wing shares its form and function with the seeds of the Javanese flying cucumber (Alsomitra macrocarpa), a fruit-bearing vine found in Southeast Asia. When its fruit, football-sized gourds, have ripened they release their seeds from high in the canopy of the rainforest. These seeds, light-weight, papery in texture, and shaped like flying wings glide to the ground sometimes several hundred meters away using autogyration to guide and slow their descent; this is the same phenomenon, for example, that guides maple trees’ “whirligig” seeds, known scientifically as samaras, to the ground. Nature is full of designs and forms that aeronautical engineers mine for the advancement of flight technology. Paul MacCready, when lecturing before an esteemed audience at MIT, once called dragonflies, hummingbirds, and hawk moths “nature’s helicopters.” Happily, each of those animals will be common in Southwestern Pennsylvania when spring and summer finally return. So, whether you’re marveling at Quetzalcoatlus northropi any time of year at the Carnegie Museum of Natural History or taking a leisurely walk at your local park, you’ll be able to ponder with renewed attention the interconnections between the natural world and the science of aviation.

Young maple tree samaras, still attached to their branches.

Nicholas Sauer is a Gallery Experience Presenter in CMNH’s Life Long Learning Department. Museum staff, volunteers, and interns are encouraged to blog about their unique experiences and knowledge gained from working at the museum.

Works Cited

Bryner, Jeanna. “How Huge Flying Reptiles Got Airborne.” Livescience.com. 7 Jan. 2009. <https://www.livescience.com/3190-huge-flying-reptiles-airborne.html>.

Carlson, Mark. “Northrop’s Radical Flying Wing Bomber of the 1940s.” July 2020. <https://www.historynet.com/northrops-radical-flying-wing-bomber-of-the-1940s.htm>.

MacCready, Paul and John Langford. “Human-Powered Flight: Potentials.” MIT Gardner Lecture, 27 April 1998. MIT Video Productions. <https://www.youtube.com/watch?v=t8C8-BB_7nw>.

Miller, David. “It’s A Bird; It’s a Plane; It’s a…Cucumber?” Boston University. 25 Nov. 2012. <http://blogs.bu.edu/bioaerial2012/2012/11/25/the-stabilizing-characteristics-of-alsomitra-macrocarpa/>.

“Texas Pterosaur Flies into Spotlight this National Fossil Day.” The University of Texas at Austin, Jackson School of Geosciences. 17 Oct. 2018. <https://www.jsg.utexas.edu/news/2018/10/texas-pterosaur-flies-into-limelight-this-national-fossil-day/>.

Super Science: She-Ra, the American Kestrel

Hi, my name is She-Ra and I’m an American kestrel. A scientist might call me Falco sparverius because that’s my species’ scientific name, but my friends just call me She-Ra or sometimes RaRa as a nickname! I may look small, but I am not—I am big, I am brave, and I am important.

American Kestrel perched on rope and wood — I’m a beautiful bird!

Kestrels like me are a part of the falcon family and are closely related to bigger birds like peregrine falcons. All the other falcons are bigger than us, because we are the smallest member of the falcon family in North America, where we are also the most populous and widely distributed falcon species. This means that there are a lot of birds like me living in the wild!

Falcons like me are raptors, or birds of prey, which means that we are meat eating birds. Wild kestrels will eat all sorts of insects, small rodents, lizards, and even smaller birds! We like to grab our prey with the sharp talons on our feet. Just like humans, some of us like to eat certain type of prey over others. My favorites are mice and bugs!

close up of American Kestrel talons — Look at my powerful talons!

I live at Carnegie Museum of Natural History in Pittsburgh, Pennsylvania, but I used to live in the wild. But I can’t live in the wild anymore: four years ago, I was hit by a car and broke my wrist, which is in the top-central part of my wing. I was taken in by the nice humans at the West Virginia Raptor Rehabilitation Center after my accident, who nursed me back to health. But even after I got better, they realized that I was never going to be able to fly well enough again to survive in the wild—even though kestrels are fierce, we’re also tiny, and sometimes bigger birds of prey try to pick on us. If I returned to the wild, I wouldn’t be able to fly away from a bigger bird! I also wouldn’t be able hover in midair, which is something really cool that kestrels can do.

American Kestrel peeking out of a Bankers Box

These are photos of me on my first day at the rehab center. It was scary, but I’m happy the humans took care of me there!

Because I couldn’t return to the wild, I needed somewhere to live, so I came to the museum, where my coworker humans take good care of me. Yes, I have coworkers because I am a bird with a job! I am an educational ambassador animal, which means I help my coworkers teach people about kestrels by appearing in Live Animal Encounters.

American Kestrel perched on the arm of a blonde person wearing a blue shirt — Here I am, doing a Live Animal Encounter with my coworker, Jo Tauber.

Coming to live at the museum took a lot of special planning, care and attention. I am protected by something called the Migratory Bird Treaty Act of 1918, as are all kestrels and over 1,000 other migratory bird species in North America. The museum needed to get special permits, which gave them permission to have me live here. There are even special permits for my coworkers, which grants them the great privilege of working with me!

The Migratory Bird Treaty Act of 1918 is important because it keeps birds safe. It prohibits people from killing or injuring birds or removing them from the wild. There are special cases like mine, where a bird needs to live somewhere they can be cared for by humans, but they are an exception. Something you may be surprised to hear is that the Treaty Act also protects eggs and nests, and even things like feathers! That’s right—even taking a feather from a protected migratory bird out of the wild is prohibited!

These are kestrel eggs. Please leave them alone if you see them!

Even though kestrels are the most populous and widely spread falcon species, wild populations seem to be decreasing. No one is quite sure why there are fewer kestrels in the wild, but some possible reasons include human interference with our habitats, the use of pesticides, bigger birds preying on us more often, and road collisions (like what happened to me).

There are things you can do to help keep my wild relatives safe. One big thing is please don’t litter, especially on roads. Litter attracts delicious bugs and mice and kestrels might try to hunt them and get hit by a car. Another thing you can do is respect our space; if you see us in the wild, just leave us alone. If we seem to be sick or injured, please call the local game commission or a wildlife rehabilitation center, they have people that are trained to take care of us, much like my coworkers are trained to care for me.

If you really feel like you want to do something more to help kestrels, look into building a nest box, which will give my wild relatives somewhere safe to lay their eggs and raise their babies. If you build a nest box, you can even monitor whether any kestrels come to use it and report that information. That will help scientists learn where kestrels are living and keep track of how many of us are in the wild!

Thank you for taking the time to read my story! I hope you enjoyed learning about me and my relatives. Please check out the videos linked below. I am the star and they can teach you even more information about me!

Enrichment Time for She-Ra

Weighing She-Ra

To report injured kestrels, or other wildlife:

PA Game Commission Southwest Region: 724-238-9523

Humane Animal Rescue: 412-345-7300

Jo Tauber is the Gallery Experience Coordinator in CMNH’s Life Long Learning Department. Museum staff, volunteers, and interns are encouraged to blog about their unique experiences and knowledge gained from working at the museum.

Detecting Objects with Invisible Waves: Using Radar, Sonar, and Echolocation to “See”

The ability to see visible waves of light can be beneficial for determining the size, shape, distance, and speed of things in our surrounding environments. But in many situations, reliance on sight might not be the best option for the remote detection of objects. For example, most animals do not have eyes on the backs of their heads; many cannot see very well at night; and some live in the depths of the ocean where visible light doesn’t reach. Yet these conditions don’t hinder the ability to sense objects for many animals. So, how do humans and other animals “see” distant objects without depending on the use of sight?

One answer is that other types of waves outside of visible light exist and animals have developed methods for detecting them. Two of these methods, sonar and radar, are man-made detection systems that allow us to “see” what our eyes can’t. The other, echolocation, is a natural way for some animals to detect motion through sound waves.

Radar

Radar is a system used to detect, locate, track, and recognize objects from a considerable distance. R.A.D.A.R is an acronym for “radio detection and ranging.” It was initially developed in the 1930s and 1940s for military use, but is now common for civilian purposes as well. Some of these uses include weather observation, air traffic control, and surveillance of other planets.

Radar works by sending out radio waves, a type of electromagnetic wave, in pulses through a radio transmitter. The waves are reflected off of objects in their path back toward a receiver that can detect those reflections. Radar devices usually use the same antenna for transmitting and receiving, which means the device switches between being active and passive. The received radio wave information can help observers determine the distance and location of the object, how fast it is moving in relation to the receiver, the direction of travel, and sometimes the shape and size of the objects, too.

Radio waves have the longest wavelengths and lowest frequencies of all electromagnetic waves. Because they move slower and require less energy, they travel well through adverse weather conditions like fog, rain, snow, etc. Detection systems like lidar that operate through infrared and visible waves with shorter wavelengths and higher frequencies do not function well in such conditions.

While radar can effectively move through or around various environmental conditions, it is much less effective underwater. The electromagnetic waves of radar are absorbed in large bodies of water within feet of transmission. Instead, we use Sonar in underwater applications.

Sonar

S.O.N.A.R, an acronym for “sound navigation and ranging,” is a similar system to radar in terms of transmitting and receiving waves through pulses to determine distance and speed. However, it functions through the use of sound waves and is highly effective underwater.

Sound waves are mechanical waves, which means they are oscillations, or back and forth movements at regular speeds, of matter. When a mechanical wave strikes an obstacle or comes to the end of the medium it travels in, some portion of the wave is reflected back into the original medium. Water turns out to be a fantastic medium – albeit a slow one – for carrying mechanical waves long distances, making Sonar the top choice for underwater object detection.

Echolocation

Echolocation is a natural sound wave transmission and detection method used by animals to accomplish the same goal of object detection. Though sometimes referred to as sonar in casual conversation, echolocation requires no human-made device to function and is used both above and below water. Animals use echolocation by sending out sound waves in the air or water before them. They can then determine information about objects in their path through the echoes produced when those sounds are reflected.

Echolocation can be utilized by any animal with sound-producing and sensing capabilities. Humans have been known to develop methods of systematically tapping canes or clicking their tongues to produce the sounds needed for echolocation. However, echolocation is more generally associated with the use of ultrasound by non-human animals. Ultrasound is sound that has a mechanical wave frequency higher than the human ear can detect though they operate the same as audible sound waves.

Bats are among the most well-known users of echolocation. They use relatively high, mostly ultrasonic wavelengths and some can create echolocating sounds up to 140 decibels – higher than a military jet taking off only 100 feet away. In order to handle such intense sound wave vibrations, bats turn off their middle ears by just before calling to avoid being deafened by their own calls. They use muscles in their middle ear to pull apart bones that carry sound waves to the inner ear leaving no path for the sound waves to damage the cochlea. Similar to radar devices switching between active transmitters and passive receivers, Bats restore their full hearing a split second later to listen for echoes.

Most of the more than 1300 species of bats use echolocation to hunt and navigate in poor lighting conditions. Fossil evidence indicates that this capability developed in bats at least 52 million years ago. They can detect an insect up to 15 feet away and determine its size, shape, hardness, and direction of travel through their skillful use of echolocation.

Wave Echoes

Animals have long been able to detect objects at a distance through the manipulation of nonvisible waves using technologies like radar and sonar or natural echolocation. Though each of these methods operates a little differently and relies on various shapes, sizes, and types of waves, they each work by emitting waves then determining characteristics based upon the echoes of those waves.

Try it at Home

Go to a corner of a quiet room and close your eyes. Without moving your body too much, try turning your head while making clicking noises with your mouth. Can you tell when you are turned more toward a wall or if there are any objects near you through the way the clicking sound changes? Try holding your hand up in front of your face and moving it back and forth while you click. Can you tell how far away it is or which direction it is moving by the sound? Get creative and try it with different types of objects and different locations!

Jane Thaler is a Gallery Experience Presenter in CMNH’s Life Long Learning Department. Museum staff, volunteers, and interns are encouraged to blog about their unique experiences and knowledge gained from working at the museum.

Carnegie’s Cactus: Carnegie gigantea

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Carnegie Museum of Natural History Blog Citation Information

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Groundhog Architecture

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Teaching About Trees

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Winging It: Quetzalcoatlus and the History of Aviation

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Super Science: She-Ra, the American Kestrel

To report injured kestrels, or other wildlife:

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Detecting Objects with Invisible Waves: Using Radar, Sonar, and Echolocation to “See”

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Sonar

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Wave Echoes

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