Drawings by Sarah C. Williams, Curatorial Assistant, Section of Botany
Super Science Days
Scientist Takeover: What is a Dichotomous Key?
A dichotomous key is a tool that allows the user to determine the identity of items in the natural world, such as trees, wildflowers, mammals, reptiles, rocks, and fish. Keys consist of a series of choices that lead the user to the correct name of a given item.
Let’s think of a plant or animal and practice using a very simple example of a dichotomous key together!
[gravityform id=”68″ title=”false” description=”false”]
Scientist Takeover: Mammals!
What is the largest mammal?
This is an easy one because it is not even close; the blue whale, which is also the largest animal to ever live on Earth, weighs around 100 tons (220,000 pounds) and is about 100 feet long. Females are typically larger than males. Despite their bulk, blue whales are filter feeders subsisting on krill, small crustaceans less than an inch in length.
In 1758, Carl Linnaeus gave the blue whale the Latin name Balaenoptera musculus. The first part, Balaenoptera, the genus name, means winged whale for its long, slender flippers; the second part, the species name, is thought to be a joke by Linnaeus because it is also the species name he gave to the house mouse, Mus musculus.
What is the smallest mammal?
This is harder than the largest one—the blue whale—because there are two mammals considered to be very close in weight: the Etruscan shrew with a Mediterranean and Asian distribution weighs in about 1.8 grams, which is less than the bumblebee bat from Thailand and Myanmar, weighing in around just 2 grams, but the shrew is longer than the bat. Remember there are 28 grams in one ounce and 2 grams is the weight of one paperclip!
What is the fastest land mammal?
The cheetah is hands down the fastest, but it does not sustain speed over a great distance; the cheetah is a burst-predator with a chase lasting typically less than a minute. The cheetah goes from 0 to 60 miles per hour in about three seconds, which is what a good sports car can do! At top speed, the length of one stride is 21 feet and there are four strides per second.
What is the slowest land mammal?
The name says it all…sloth! There are two types of sloths found in the tropics of Central America and northern South America, usually called three-toed and two-toed sloths. This is a misnomer as both types have three toes on their hindfeet; what differs is the number of fingers on the forefeet. So, they really should be called three- and two-fingered sloths. Both sloths live most of their lives in trees on a diet of leaves and move so slowly or so little that algae grow on their fur, providing camouflage. Of the two sloths, the three-digited one is smaller and slower.
What is the strongest mammal?
This is just a playful question. It usually isn’t one of the comparisons that scientists try to make. However, the armored hero shrew seems like a good nominee. This shrew lives in the forested region of central Africa. Its spinal column is unique among mammals. The mid-portion is extremely modified with many interlocking bony tubercles that project forward and backward to fortify the spine. The exact purpose is unknown. However, it has been reported that a full-grown man could stand on the back of an armored shrew without harming the animal.
John Wible is Curator of the Section of Mammals and Sue McLaren is Collection Manager of the Section of Mammals at Carnegie Museum of Natural History. This post is part of Super Science Days: Scientist Takeover!
Related Content
Stuffed Animal Safari: Mountain Goats
Super Science: The Virtual Amazon
No, we’re not talking about a video game featuring an ancient woman warrior. We’re talking about making the museum’s Amazon Basin collections electronically accessible to the people of that region, as well as to scientists and the public. Through collaboration with the indigenous people whose cultures these objects represent, we hope to more widely and authentically share information about the way of life in Amazon Basin villages. The significance of fishing, hunting, gardening, and even rituals ablaze with celebrated feather work can all be better understood through the visual exploration of materials already in the CMNH collection.
With the ongoing massive deforestation in the Amazon by neo-Brazilians for logging, farming, and mining, the “lungs of the world” are under threat, as are the lives of the indigenous people whose way-of-life depends on the flora and fauna of the forest they have managed successfully for centuries. If the forest disappears, or is even diminished much more, its loss will have a devastating effect on the world’s climate. A number of scientists and non-government organizations (NGOs) from Brazil and other countries are partnering with the indigenous people to preserve their lands, their cultures, and their lives.
Although the CMNH project will take some time—and a lot of planning and resources, the growth of collaborative efforts to address the looming threats to the Amazon Basin have made conditions optimal to bring collections-centered stories to the American public. The idea to provide wider access to the artifacts got started two years ago, when on September 2, 2018, Museu Nacional, the national museum of Brazil, was almost entirely destroyed by a fire. The blaze destroyed a magnificent natural history collection, and also one of the largest archeological and ethnographic collections in the world. The institution’s holdings of Amazon Basin material were unparalleled, and are now gone.
By great good fortune and the foresight of then-curator James B. Richardson, the CMNH Section of Anthropology developed an outstanding Amazon Basin collection, starting in the early 1980s. Richardson was also a professor of anthropology, and divided his time between the University of Pittsburgh and the museum. As an archeologist working in Peru, he regularly advised South American-focused graduate students. Whenever one of these students prepared for fieldwork, Richardson would make museum funds available for artifact collection and shipping. Through this process, and aided by purchase of existing collections, the museum amassed materials from 72 Amazon Basin tribes. The three most-complete assemblages (with associated collectors) are from the Yanomamo [Dr. Giovanni B. Saffirio], the Kayapo [Dr Darrel A. Posey], and the Kuikuro [Dr Michael J. Heckenberger]. With the loss of Museu Nacional, these collections are now the best and most complete in the world.
The COVID-19 pandemic has made it difficult to predict project timing, but we plan to eventually document every relevant item with high-resolution digital images, and a smaller number with 3-D images, beginning with the Kuikuro collection. Ideally, we would like to bring several Kuikuro people to Pittsburgh to co-curate the artifacts by identifying component materials, and explaining each item’s creation process and use.
Dr. Heckenberger, whose archeological findings were recently featured on the Discovery Channel’s 3-part series, “Lost Cities of the Amazon,” continues to work with the Kuikuru in the upper Xingu River basin. Chief Afukaka Kuikuro, who helped Heckenberger gather materials for the museum in the early 1990s, and is involved in other collaborative projects, will likely play a critical role. Because ethnographers were historically male, women’s views and artifacts got short shrift in museum research. In an effort to remedy such bias, several Kuikuro women will be included in the project.
What will be the outcome of this endeavor? At the very least, a small exhibit in the museum will make select artifacts accessible to the people of the Pittsburgh Region as windows into the culture of the Kuikuro. Other possibilities include an online catalog, or a large installation with visiting Kuikuro to present lectures and show the films of film-maker Takumā Kuikuro. At the very least, artifact images will be shared with the Kuikuro themselves, so that they have a record that will remain available to their craftworkers, children, and grandchildren.
These ambitious plans might not happen anytime soon. With time and funding, however, bringing these wonderful objects to the attention of the public will provide a glimpse of life in a very different world. The Kuikuro have much knowledge to share, and we’d like to be a part of making it available to the rest of the world.
Additional resource: The Xingu Firewall
Deborah Harding, M.A. is the Collection Manager of the Section of Anthropology at Carnegie Museum of Natural History. This blog is part of Super Science Days: Scientist Takeover!
Related Content
Scientist Takeover: What is a Dichotomous Key?
Meowfest: Oglebay Good Zoo Big Cats
Cats: The Original Social Distancers
Science is always changing as ideas grow and evolve—it’s one of my favorite things about the topic. During my undergraduate years at Canisius College, I joined a research team to experience this first-hand. We were focused on studying the welfare of shelter cats to find ways to lessen their stress, so they were more likely to be adopted. The project I worked on focused on space requirements in colonially-housed cats and the conclusions are very relevant to current world events. I am lucky enough to have worked with an amazing advisor who has become a very good friend—Dr. Malini Suchak, Associate Professor of Animal Behavior, Ecology, and Conservation at Canisius College and Feline welfare and cognition researcher. I reached out for her personal experience and description of some of the findings of the project:
Although I’ve studied cats for eight years, and animal behavior much longer, the pandemic has offered me a unique, 24 hours per day look into my cat’s life. I’ve found myself fascinated by how he socializes with me on his own terms—at times endlessly “Zoom-bombing” my meetings, demanding attention, and other times disappearing for hours at a time into some secret napping spot I still haven’t found. This independence of spirit at least partially stems from the fact that cats were domesticated from a solitary species, the near Eastern wildcat. In fact, in true independent cat fashion, we didn’t domesticate them; they did it themselves in a process called self-domestication that took place about 9,000 years ago.
Fast forward to 2020, and we have a (sometimes) cuddly companion, living a posh life in the house, sometimes with other cat companions. Cats are interesting because their ability to tolerate (or maybe even like) being around other cats is dependent on them being exposed to other cats early in life. They tend to vary a lot in this regard; while some cats have close friends, most fall somewhere between accepting other cats and barely tolerating their presence.
When they do live together, whether at home or in animal shelters, cats are experts at keeping distance between themselves and others, which might help them cope with too much social contact. They might “time share” favorite resources like a box or a windowsill, where everyone gets a turn at different times of day. They use items in their environment, like shelves, crates and boxes to create “personal space bubbles” and physically separate themselves from others. All these actions help increase their distance, or their sense of distance from other individuals.
In fact, we found that cats living in groups at a shelter kept an average of 6ft (2m) from each other. If that sounds familiar, it’s because that’s the recommended distance we humans should maintain to social distance and reduce the spread of coronavirus. We also found that cats living in groups were no more likely to develop an upper respiratory infection than those housed alone, despite the fact that you would predict exactly the opposite—increased disease-risk is one of the major costs of living in groups. Now, there could be a lot of reasons why the disease rate was the same, but we can’t discount the fact the cats naturally keep the recommended distance between themselves.
Being part of this team changed my life in many ways; I realized collecting and processing data (which is most of research) wasn’t what impassioned me. I found I loved teaching others what the research was discovering instead.
So, here’s hoping you enjoy the rest of Meowfest a comfortable distance from your feline friend!
Abbey Hines is a Gallery Experience Presenter as well as an Outreach Educator and Animal Handler in CMNH’s Life Long Learning Department.
Dr. Malini Suchak teaches courses in introductory animal behavior, animal cognition, and animal welfare at Canisius College, as well as researches how nonhuman animals think about other individuals in their social groups.
Related Content
Cat Chat 101: The Basics of Domestic and Wild Vocalizations
