Welcome to an exciting journey into the world of whales, dolphins, and porpoises! Today, we’re visiting the Smithsonian’s Whale Warehouse, the largest collection of whale materials in the world. This amazing place is located in Maryland, just a short drive from Washington, D.C. Here, scientists study both living and extinct marine mammals to learn more about these fascinating creatures.
Dr. Michael McGowen, a curator of marine mammals, introduces us to some incredible animals known as cetaceans. Cetaceans include whales, dolphins, and porpoises. One of the most familiar is the bottlenose dolphin, but did you know there are also river dolphins? These dolphins, like the Amazon River Dolphin and the Indian River Dolphin, have adapted to live in rivers, even though they’re not closely related. This is an example of convergent evolution, where different species develop similar traits independently.
The Indian River Dolphin has special growths on its skull to help it navigate using sound, a process called echolocation. This is crucial in murky river waters where seeing is difficult. Bottlenose dolphins also use echolocation but in a different way, without the bony growths.
One of the coolest things about the Whale Warehouse is how scientists use old specimens to learn new things. For example, a skin sample from an Indian River Dolphin collected in 1910 can be used to study DNA and understand how the species has changed over time. This helps scientists see if there’s been a loss in genetic diversity, which is important for conservation efforts.
We also meet the pygmy sperm whale, known for its asymmetric skull, which helps it with echolocation. These whales have a unique ability to squirt ink, similar to a squid, possibly to escape predators. Another fascinating creature is the narwhal, famous for its long tusk, which is still a bit of a mystery to scientists.
Some whales, like the strap-toothed whale, have very unusual teeth. Their tusks grow in a way that limits how wide they can open their mouths, so they feed by sucking in squid. Other whales, like baleen whales, don’t have teeth at all. Instead, they use baleen plates to filter food from the water. By studying baleen, scientists can learn about a whale’s diet and even its stress levels over time.
Did you know that whale earwax can tell us a lot about their age and life history? Like tree rings, layers of earwax build up over time, providing a record of a whale’s life. Another interesting substance is ambergris, found in the intestines of sperm whales. It has a pleasant scent and is used in perfumes!
Finally, we learn about the vaquita porpoise, a critically endangered species with only about 17 individuals left in the wild. Having specimens like the vaquita’s skull in museums is crucial for research and conservation. Even if these animals disappear from the wild, scientists can still study them and learn valuable lessons.
Thanks to the Smithsonian and museums like it, we can continue to explore and understand the incredible diversity of marine mammals. Every specimen, no matter how old, holds the potential for new discoveries.
Research different species of cetaceans, including whales, dolphins, and porpoises. Create a family tree that shows how these species are related. Include interesting facts about each species, such as their unique adaptations or habitats. Present your family tree to the class and explain the concept of convergent evolution using examples from your research.
Choose a specific whale species and create a poster that highlights its unique adaptations. Include information on how these adaptations help the whale survive in its environment. Use drawings, diagrams, and labels to make your poster visually appealing. Share your poster with classmates and discuss the importance of these adaptations.
Imagine you are a scientist at the Smithsonian’s Whale Warehouse. Choose a whale specimen and write a report on what you could learn from it. Consider aspects like DNA analysis, genetic diversity, and historical changes in the species. Present your findings to the class and discuss how this research can aid in conservation efforts.
Learn about echolocation by conducting an experiment. Use a blindfold and a simple sound-making device, like a bell or a whistle. Have a partner guide you through a course using only sound. Reflect on the challenges and discuss how cetaceans use echolocation to navigate and hunt in their environments.
Research the critically endangered vaquita porpoise and create a conservation campaign. Develop a presentation that includes the current status of the vaquita, threats to its survival, and actions people can take to help. Present your campaign to the class and brainstorm ways to raise awareness in your community.
This episode is brought to you through a collaboration with the Smithsonian’s National Museum of Natural History in Washington, D.C., and the Field Museum in Chicago, Illinois.
Emily: We’re here at the Smithsonian’s Whale Warehouse, which is the largest collection of whale material found anywhere in the world. The Whale Warehouses are located at the museum Support Center in Maryland, about 45 minutes away from the Smithsonian’s location on the Mall. It’s actually two giant warehouses that house both extant and extinct specimens. With over half a million square feet of storage space, the Museum Support Center is home to some of the largest specimens ever collected, like the 23-foot-long right and left jaw bones of the largest blue whale specimen in any museum in the world. Today, we’re going to talk with Curator of Marine Mammals, Dr. Michael McGowen, about cetaceans—marine mammals like whales, dolphins, and porpoises—and see how the Smithsonian’s Natural History Museum is using their collections in unexpected ways to better understand this diverse group of animals.
Michael: First, I just wanted to show this generic bottlenose dolphin that people are really familiar with, and compare that to these other forms over here. These are different river dolphins, including the Amazon River Dolphin and the Indian River Dolphin. They are not closely related but have invaded river systems separately.
Emily: So this is a case of convergent evolution?
Michael: Yes, it is. The invasion of rivers is an instance of convergent evolution. The Indian River Dolphin has growths on its skull, which some interpret as an adaptation for navigating in environments where they can’t rely on vision. They use echolocation, which reverberates off the bone and helps them “see” through sound. Bottlenose dolphins also have echolocation but do not have these bony protuberances, allowing them to focus their echolocation broadly into their environment.
Emily: Gotcha.
Michael: This is one of the bizarre things in the collection. This is a skin sample from an Indian River Dolphin. We can sample DNA from specimens like this to understand genetics from the past. This specimen was collected in 1910, and we can compare it to the species today to see if there’s a reduction in diversity. In the case of rare specimens, this might be one of the few left of this species outside of India or Pakistan.
Emily: That’s a great example of how when this was collected, it wasn’t clear how it could be used in the future, but now, thanks to technology and advancements in DNA analysis, you can make use of it in ways that were not predicted before.
Michael: Exactly, and we can do that with bone as well. All of these specimens now become genetic repositories of specific points and places from the past.
Emily: That’s pretty mind-blowing.
Michael: It is pretty mind-blowing.
Emily: Can I smell it?
Michael: Sure!
Emily: Is this weird? I’m sorry.
Michael: It’s not weird at all. The smell of marine mammals is lovely.
Emily: It smells just like leather. This smells just like shoes.
Michael: Well, it’s made out of a lot of the same material that our skin is.
Emily: This smells pretty good.
Michael: This is a pygmy sperm whale. They have some of the most asymmetric skulls among cetaceans. This is their nasal passage, which goes up to the blowhole. You can see one side is much larger than the other, which is related to echolocation. They can tell the direction of sound based on this asymmetry.
Emily: That blew my mind!
Michael: These animals are really unique. They also have an anal sac that can squirt ink.
Emily: Like a squid?
Michael: Yes, they feed on squid, and it’s thought they may use some of the ink to squirt at predators.
Emily: Wow! I had no idea! So these guys are just unique?
Michael: Yes, cetaceans have evolved many bizarre tooth morphologies. One example is a narwhal’s tusk, which is mostly found in males, although about 10% of females have one. It’s thought to be used for male-male competition, but its exact purpose is still a mystery.
Emily: So, what is this thing?
Michael: This is a model of a strap-toothed whale, whose tusks grow together and completely enclose the mouth. It can only open its jaw a little bit.
Emily: How does it eat anything?
Michael: It feeds on squid by sucking them in, so it doesn’t need a large gape.
Emily: That is very weird.
Michael: Cetaceans have a lot of unusual dental structures.
Emily: We were just discussing the diversity of cetaceans, and while we are in a museum collection, we don’t just look at skeletal material when we have questions.
Michael: Right, I brought out some other materials we might collect. One of the things people might know about is baleen. Many large whales don’t have teeth and feed by filtering through baleen.
Emily: That’s what this is?
Michael: Yes, as you can see, there are different plates. Water comes through, and food gets caught in the fringe-like structures.
Emily: Hair-like structures.
Michael: Exactly. Baleen grows incrementally throughout the whale’s life, so by drilling at different points, we can learn about what the whale was doing at those times.
Emily: Wow!
Michael: We can analyze hormones, cortisol levels (indicating stress), and isotopes to understand their diet and feeding locations. We can even look at baleen specimens from the 1800s to learn about whale life back then.
Emily: That’s amazing! So it’s like a time machine through the mouth of a whale?
Michael: Exactly, a time machine.
Michael: Another piece we can study is earwax.
Emily: Their earwax?!
Michael: Yes! It’s a lipid-like structure in the ear canal of a whale. Different layers are deposited throughout their life, allowing us to age large whales.
Emily: So it puts down layers like a tree?
Michael: Yes, it’s like a whale’s tree-ring.
Emily: That’s a little gross, but I’m okay with it.
Michael: In this collection, we also have this fragrant piece that looks like resin. What is this?
Michael: This is ambergris, from the intestinal tract of a sperm whale. It’s still used in perfumes today because it has a wonderful musky scent.
Emily: Admittedly, it does smell really good. It kind of smells like sandalwood or an earthy, tree-like scent.
Michael: Yes, it’s essentially condensed waxy whale waste.
Emily: That’s an interesting way to describe it!
Emily: We’ve talked a lot today about the diversity of whales and the importance of their specimens in collections like this one at the Smithsonian. We have one last specimen to discuss, which highlights why these collections are so important for research.
Emily: This is a species called the vaquita porpoise. It lives in the Gulf of California, and there are only about 17 individuals left. This serves as a cautionary tale. At least we have this specimen in the museum, so hopefully, they won’t go extinct, but if they do, we have representations of them here.
Michael: Exactly! This skull can help answer questions about an organism that might not be available for study in the wild. We don’t know what new scientific advances will occur and what information we could extract from this skull. When some of these specimens were collected in the 1880s, they had no idea we could extract DNA or analyze isotopes or hormones from baleen, but it’s great that all this material is preserved. Every specimen, no matter how old, is valuable.
Emily: Thanks, museums!
Whales – Large marine mammals that are part of the cetacean family, known for their impressive size and intelligence. – Whales migrate thousands of miles each year to find food and warmer waters for breeding.
Dolphins – Intelligent and social marine mammals that are closely related to whales and porpoises. – Dolphins use a series of clicks and whistles to communicate with each other in the ocean.
Porpoises – Small, toothed marine mammals that are similar to dolphins but have shorter beaks and different fin shapes. – Porpoises are often seen swimming in coastal waters and are known for their shy nature.
Cetaceans – A group of marine mammals that includes whales, dolphins, and porpoises. – Cetaceans are adapted to life in the water, with streamlined bodies and flippers for swimming.
Adaptations – Changes in physical structure or behavior that help an organism survive in its environment. – The thick blubber of seals is an adaptation that helps them stay warm in icy waters.
Echolocation – A method used by some animals, like bats and dolphins, to locate objects by emitting sounds and listening for the echoes. – Dolphins use echolocation to hunt for fish in murky waters where visibility is low.
Conservation – The protection and management of natural resources to prevent exploitation, destruction, or neglect. – Conservation efforts are crucial to protect endangered species from extinction.
Diversity – The variety of different species and forms of life found within a particular environment or ecosystem. – The Amazon rainforest is known for its incredible biodiversity, hosting thousands of plant and animal species.
Species – A group of similar organisms capable of interbreeding and producing fertile offspring. – Scientists discovered a new species of frog in the remote jungles of Madagascar.
Preservation – The act of maintaining or protecting something in its original state or in good condition. – Preservation of natural habitats is essential for maintaining the balance of ecosystems.
