Webinar: Expedition to the Island of the Land Crabs

Webinar: Expedition to the Island of the Land Crabs

Aired March 31, 2022

Maggy Benson:

Welcome to Smithsonian Science How. We are so happy to have you here. My name is Maggy Benson, and I am a museum educator at the Smithsonian National Museum of Natural History and the host of Smithsonian Science How. I am here in Washington, D.C., where it's a little bit dreary so I am extra excited to travel to the tropical Christmas Island with our scientist Vicky Watson-Zink today to learn all about crabs. I hope you're excited too.

Before we meet Vicky, I want to go over just a couple of details about today's program. We are on a webinar, so a couple of reminders about a webinar. You will not be able to turn on your video or your microphone during today's program. However, you can communicate with us using the Q&A space, which you'll find on your Zoom window, and also with the polls. We have a lot of polls for you today. So those will pop up on your screen and you can vote in them. And we invite you to send questions in for Vicky because throughout today's program, we will be taking questions. We'll go through our program for about 45 minutes, and at the end, Vicky is going to answer as many questions as she can.

Today's program has closed captions. So to activate them, find the CC button on your Zoom window and click show subtitles. And finally, we have ASL interpretation today. So, thank you for the interpretation. We will be pinning that the entire time so you should be able to see it. If you do have trouble seeing the ASL interpreter, send us a message in the Q&A, and our team of educators behind the scenes who make this program possible will help troubleshoot.

One more detail before we dive in and meet Vicky, is we want to tell you about our program next week. Smithsonian Science How will be hosting ForestGEO's Nidhi Vinod, and she is going to be exploring how plants breathe and the connection to how plants breathe to forests in climate change. So that is next Thursday, April 7th at 1:00 PM Eastern Time. So we hope you can join us for that too.

Now, I want to introduce our scientist today, who is going to take us on a very special expedition, and that is Vicky Watson-Zink. Hello, Vicky. Thank you so much for joining us today.

Vicky Watson-Zink:

Hi. Hi everybody. It's so great to be here. I'm very excited to come and talk to you about a topic that's really close to my heart and in the work that I do at UC Davis as a graduate student. I'm just going to change something with annotation here. Sorry.

Maggy Benson:

Yep, looks great.

Vicky Watson-Zink:

Great. Awesome. So, I'm excited to take you to the wonderful island of Christmas Island, which is where I do a lot of my research as a graduate student. And today we're going to do a lot of really great work about learning about land crabs. So let's go ahead and get started. So first, a little introduction about me. I am Vicky. This is a picture of me when I was around your age. Really cute smile.

Part of what my background I want to talk about is, I grew up near the ocean. So this is a picture of John U. Lloyd Beach in Miami, Florida, and I spent many wonderful days out at this very beach in Miami when I was around your age. And I remember just running along the sandbars in the ocean with my cousins, collecting seashells on the shore, and just digging around in the scrub, looking for weird animals. I was a bit of a wild child, but that love for nature and my curiosity about animals and living things is something that defines me now as a scientist. And it's super important to how I approach my work now that I'm older.

Maggy Benson:

What a wonderful place to grow up.

Vicky Watson-Zink:

Yeah, it was fantastic. This is a more recent photo of me, collecting crabs in Zanzibar a few years ago. You can see from the huge smile on my face that not very much has changed. And even today, I still love the ocean and I love that my job every day gets me out there exploring all the ocean's mysteries. And so I'm really excited to come and share some of that and what I've learned with you during this webinar. So the first thing I want to do is start off with a really quick poll about crabs to see how much all of you know. So, true or false, all crabs live in the ocean.

Maggy Benson:

All right. So you'll see a poll pop up on your screen. Tell us what you think. All crabs live in the ocean. Is that true or is that false? All right. I'm thinking about my experience, all the crabs I have ever seen and held in touch have lived in the ocean. I wonder what you all think. All right. It looks like most of our friends have voted, so we will close it in about five, four, three, two, one.

Vicky Watson-Zink:

Wow. Excellent job. So yes, most of the crabs you might be familiar with that you might eat, if you eat seafood, do live in the sea. But today, I'm taking you on an expedition to learn about a lot of really cool crabs that actually don't live in the ocean anymore. They've adapted to living completely on land, which is a really exciting transition. So great job on everybody who voted. Let see how I get rid of that poll.

Maggy Benson:

You can just hit the red X to make the pole go away. It won't impact anything. So just drag it off your screen or hit the X.

Vicky Watson-Zink:

Perfect. Great. So yes, the correct answer is false. The next poll I have is just, what do you think crabs need water for? So do you think crabs need water to drink? Do you think they need it for breathing? Do you think they need it for using the bathroom, reproduction, or all of the above? So what do you think crabs use water for?

Maggy Benson:

All right. So we're going to the next step. We know that all crabs don't live in the ocean, but they all need water. What do they need that water for? All right, everybody is voting. It's wonderful. And we have some friends that have said hello. So hello, Dan. We're happy to have you here. Hello, Sarah. Thanks for joining us today.

Vicky Watson-Zink:

I'm seeing a lot of really good answers.

Maggy Benson:

We have a clear winner, but we'll give you all another couple of seconds. All right, we'll do another countdown. We will close this in five, four, three, two, one. All right. Great job using the polls, everyone.

Vicky Watson-Zink:

Yeah, great job and great answers too. So no matter what you guess here, you're kind of right in a different way, but the correct answer is all of the above. So crabs need water to drink. They need water for breathing. In my field, we call it respiration. They use the water to go to the bathroom, to reproduce. So the correct answer is all of the above, but thank you so much for all of your answers. Great.

So, I just want to give you a really quick introduction of Christmas Island. This is a picture from Christmas Island right on the shore. It's often called the Galapagos of the Indian Ocean, just because it's really diverse and really wild. And even though it's a very small island and you can probably drive around the whole island in a few hours, it has more species of land crabs living on that island than on any other place on earth, which is amazing. So if you love land crabs, like I do, Christmas Island is the place to be. It's just a magical, magical place.

So, I just want to give you a quick overview of what we're going to be doing today. And I want to thank all of you for signing up to my field assistants to go into the field with me. So the first thing we're going to do is visit four unique habitats on Christmas Island. We'll be going to the lower intertidal zone, the upper intertidal zone, sandy beaches, the coastal forest, and the tropical jungle. At each of those sites, we're going to look for land crabs in each habitat. So land crabs are really cool because they actually can be found in all of those really cool habitats. And so we're going to learn about those today. We're going to take field notes to learn about how these crabs are adapted to such different environments. And finally, we're just going to do a quick compare and contrast between the different species to see what comes out of that comparison. So, I have a really fun action packed day plan for all of you and I'm really excited to have you here.

Maggy Benson:

I can't wait to tag along. All right.

Vicky Watson-Zink:

Yeah. So a little bit about the data that we're going to be collecting about each crab. I've given you all a field notebook, and so the first thing I'm going to do is just write the crab's name on a sticky note. We're going to take a picture of the crab and then we're going to just take some notes about what we're observing. So how does a crab look? How do we think that crab breathes? What might that crab eat in its habitat? Where, specifically in that habitat, does it live? And how often does that crab reproduce based on some stuff I'm about to tell you right now?

In terms of how it looks, some observations you can take: What color is the crab? How big is it? What do its claws look like? What do its legs look like? So those are just some quick notes you can take about just what you're seeing from each of the crabs. In terms of how it breathes, marine crabs, the one that live in the ocean, breathe with gills, a lot like fish. And so this is just a picture of a marine crab with its carapace, the body part sort of opened up. And you can see that there are these little feather-like things along the sides of the carapace that it uses to breathe. But land crabs are different because gills are not as useful on land as they are in the water. And so land crabs have actually evolved a lung. And so this is the same sort of picture of a different crab that lives on land. And it has these tissues on the side of its inside of the body that it uses to breathe, that work like a lung.

So basically, how does it breathe? You can tell me whether you think it breathes with gills or whether you think it breathes with a lung, depending on how far it is from the ocean. So again, marine crabs will most likely have gills. Land crabs will most likely be breathing with a lung.

Maggy Benson:

Very cool.

Vicky Watson-Zink:

Super. What does it eat? It can either eat food from the seas, so things like dead fish and dead animals, seaweed, or marine snails. Or maybe if it lives more on land, it's eating food from plants. So that can be things like coconuts or fruit or leaves. And so marine crabs, because they live closer to the ocean, are more likely to eat food from the sea, and then land crabs are more likely to eat food that comes from plants on land. In terms of where it lives, I'm going to tell you a little bit more about this as we're going along, and so this might not be a pole that you'll do. But if a crab is living sort of near the water, it's more likely to be between the rocks. So if you've ever been in the intertidal, you might have seen crabs hiding in the rocks. But land crabs dig little burrows for themselves on land. So just little holes in the ground where they go to live and hide their food and reproduce.

And finally, in terms of reproduction, do you think it reproduces many times a year, or maybe just once a year? So again, marine crabs, because they're close to the ocean and all crabs need to develop their larvae in the sea, might reproduce many times a year because it's easier for them to drop their eggs in the water because they're closer to the ocean. But land crabs tend to only reproduce once a year because they're further from the ocean and they have to go back and migrate and drop their eggs in the water, so they reproduce once a year. So that's a lot, but we're going to give you a lot of hints as we're going along to keep track of things. But yes, we're just looking at how they look, how they breathe, what they eat, where they live, and how often they reproduce.

Maggy Benson:

And Vicky, this is real data that you collect when you go out into the field. So this isn't just an activity today for our friends who are watching, but this is actually simulating the kind of work that scientists do when they're doing field work.

Vicky Watson-Zink:

Yes. And so when I went to Christmas Island to do my field work, these were the kind of data that I were collecting. So you're actually really helping me do something that I do every day as a scientist. So, very, very realistic. In terms of why we're collecting all this data, we want to learn all the different ways that crabs are adapted to their environments and we want to see how these different traits or adaptations change as we look across these different habitats. So this is important because we can understand how the crabs might be related to each other. And since all lives started in the ocean, understanding how the crabs have adapted to living on land might tell us a little bit more how other animals have adapted with the living on land a long, long time ago. So really big questions in biology. So, pretty important work.

Great. Now that the spiel is over, we can pack to go to the field. So in the picture, I have all the stuff that I brought when I went to Christmas Island, so lots of equipment. But for today, all you'll need is a pencil, a notebook, and your awesome powers of observation. So if everybody's got all of that packed, we can go ahead and stamp your passport and get moving. And we're going to head to Christmas Island, Australia.

Maggy Benson:

All right. And this is a reminder for our friends. We are going to go into our expedition now. But if you have questions for Vicky along the way, just put them in the Q&A space, and we will be able to answer those or give them to Vicky so she can answer them. All right, Vicky, let's go to Christmas Island.

Vicky Watson-Zink:

We're boarding the plane. It is a very, very long flight. So if you are in D.C. right now, this is where D.C. is roughly on the map in United States. You have to fly across the United States to San Francisco, which is near where I live, I'm in Davis in California. Then you have to fly all the way across the Pacific Ocean to Sydney, Australia. And that's a really long flight, it takes about 18 hours. It lasts forever. Then you have to fly across Australia and then finally up to Christmas Island, which is a territory owned by Australia. So, very, very long flight. And so I just want to ask really quickly, have any of you ever been on a plane? And what's your favorite thing to do on a super long flight?

Maggy Benson:

Great. While our friends are typing into the Q&A, I will say my favorite thing to do is to sleep and watch movies.

Vicky Watson-Zink:

Same for me. I like to sleep. I like to eat a lot of snacks and then watching all the movies that show on the entertainment screen. That's definitely what I like to do.

Maggy Benson:

Oh, we have a friend that wants to go on a plane one day. All right. Definitely.

Vicky Watson-Zink:

Really.

Maggy Benson:

Watching movies. Irene, Megan wants to eat food, look at city lights. All right. Sleep and watch movies for Brantley. "I like to read and look out the window, trying to find water like lakes."

Vicky Watson-Zink:

That's really fun too, to just see what you can see from the airplane window. I have some cool photos of Christmas Island from the airplane window that I'll show you later.

Maggy Benson:

And a couple other friends want to go on a plane. Well, we will take you on a trip where you don't have to go on a plane today. All right. So we've flown, we've watched some movies, we've had some snacks, looked at some lights and some water out the window. What does it look like when we arrive in Christmas Island?

Vicky Watson-Zink:

We have now arrived in Christmas Island. So this is the Christmas Island Airport. It is very, very tiny. There's like half a terminal in there. It's really just a shack where the planes land. We've rented our field car, and now we're driving through the jungle to head into our first field site. So I hope you're really excited to see this first site. So the first site we're going to is named Dolly Beach. And at Dolly Beach, we're going to be looking at a habitat called the intertidal. When the tide goes out, it exposes lots of habitat where lots of animals live, so not just crabs, but we're going to find crabs in this space. And so this is just a picture of the intertidal zone at Dolly Beach. And so I just wanted to start with a quick question to see what you might have done or what you might expect to find in a habitat like this.

Maggy Benson:

Okay. So think about what kind of animals might live in this kind of habitat, which is a tide pool.

Vicky Watson-Zink:

Yeah. So have you ever gone tide pooling? And what kind of animals might you find in a tide pool?

Maggy Benson:

All right. We're looking at that Q&A. I know I used to work in tide pools and I used to love discovering new things. I felt like every time I visited a tide pool, I saw some kind of surprising thing happening in there, between the plants and the animals. All right, I'm going to read some of these responses for you, Vicky. Heather says, sea star; Irene, sea creatures; Ariana, clams; Robin, crabs, snails, periwinkles, sea stars, and urchins. All right, what is tide pooling? That's exploring those spaces right in between the rocks where the tide comes in and the tide goes out every day. Starfish, mollusks, barnacles, kelp, hermit crabs, snails, slugs, shellfish, urchins, crabs, manta rays. All right, what do you think, Vicky?

Vicky Watson-Zink:

All of those sound excellent to me and I've actually seen a lot of these animals in the tide pool myself. Manta rays tend to like deeper water, but that's a really good guest because they do live in the ocean. You might find other types of rays. So I think... I forgot the name of them, but there are some ways that might live closer to shore than manta rays. Definitely lots of snails, whelks, periwinkles, sea stars, sea urchins, sea cucumbers, lots of really cool stuff. I've even seen octopus once in the tide pool. So there's lots of really cool animals that live in the tide pool.

Great. So let's take a closer a look at that tide pool. So here it is. You can see that the water has receded. We see lots of the rocks that are exposed now that the tide has gone up. Oops, that went too fast. And then if we look at a certain part of the tide pool, we see... Boom, we found our first species of crab. Look at these creatures. They're pretty funny looking. So now we're going to start taking data on this crab that we've discovered. So this crab is called the red-eyed rock crab. So again, we're just going to first ask you, what do you see? What does a crab look like? Can you describe what you're seeing? And then we're going to do a poll to ask you how you think it breathes, what do you think it eats, and how often it might reproduce.

Maggy Benson:

All right. So now is your turn to be the scientist, use your powers of observation to tell us a little bit about how this crab looks. And remember those clues that Vicky gave us. You can look at its color, its claws, its legs. All right. And while you're answering that, we did have a question. Robin wants to know how warm the water is.

Vicky Watson-Zink:

Oh, it's like bath water. It's very, very warm. It's very nice to be in, very nice to swim, which is very different than the water we have in California, which is very cold. I think a lot of people wear wet suits out in California when they go in the water because it's very chilly, but this water on Christmas Island is very, very warm, great for snorkeling and scuba diving.

Maggy Benson:

Okay, so I'm going to read some of these observations. Red eyes, looks like a zebra with red eyes, orange red eyes, and it looks like it can camouflage.

Vicky Watson-Zink:

Oh, good.

Maggy Benson:

Big claws, white under the body and top, two front claws, gray brown top with a white bottom, one claw is larger than the other, has red eyes. It lives in the sea. It looks evil. All right, so how did our field assistants do?

Vicky Watson-Zink:

Excellent job. And there's some really awesome observations that I saw in there. I saw that someone said that it might be really good at camouflaging because the rock site it's on are very dark and so the body's very dark. So you imagine that it might be easier for it to hide from predators because of its body color. I saw an observation about the different claw sizes. So there's one really, really big one, and then a smaller one. I think the question was, is it always on one side or another? And so this is variable. So some crabs, once they have a claw that's big, that is a big claw forever. But then some crabs, once they drop that, they can switch which claw is bigger. So that's actually an active area of research, is how do you determine handedness, so right or left handedness in a crab. So, cool observation. That's a whole research study that's happening.

Maggy Benson:

That is very cool. Shall we launch our next poll so they can practice some of those other science skills?

Vicky Watson-Zink:

Yes. Yes.

Maggy Benson:

All right. So now you're going to have a chance to look at some of those other questions and make some predictions about how this crab breathes, how it eats, and how often it reproduces.

Vicky Watson-Zink:

I also see a question in the chat about, have I been pinched by a crab? Yes, it is not fun. It hurts quite a lot. When was the first coconut crab discovered? I don't know the exact date, but I do know that Charles Darwin, who's really big in our field of evolutionary biology, actually described coconut crabs in one of his journals. So a long time ago.

Are crabs like friends for you? I mean, I spent a lot of time with crabs, so probably yes. I just love them. They're just a fascinating group. Why do they have hairs on their legs? There's a lot of different reasons why that might be. Some crabs have hairs and they can actually grow algae on their leg that they can eat. Some crabs that live on land use those hairs to pull up water because water's a stressor. When they don't have water, they get stressed out. So lots of different reasons why they might have the hairs on their legs. Are they friendly? Not often. It's going to be sort of eerie, kind of angry little animals, especially if you pick them up.

Maggy Benson:

Great questions, everyone. We're going to end this poll now to look at some of your other responses in three, two, one. All right, so many good responses. So, Vicky, talk us through these.

Vicky Watson-Zink:

Great. So the first one, how does a crab breathe? We see that most people here said that this crab probably breathes with gills. And I would think that way too, because it is very close to the ocean. It's very easy for it to just dip back into water and breathe. So crabs that live in the intertidal zone do tend to breathe with their gills. So, great job on that one. What does it eat? Most likely, food from the sea. True. So this crab has that really big claw because what it likes to eat is snails. It's really nice for smashing snail shells. And how often does reproduce? Many times a year. So that's a great, great guest because it's very close to the ocean, it's very easy for it to go back and reproduce in the water. So, great job, everybody, on answering that pole.

And so here's just the completed version of our field notes from the red-eyed rock crab. So we noticed it was dark, it was spotted or striped with large claws and pretty short legs that have hairs. It breathes with its gills. It's a shell crusher so it eats snails, food from the sea. It likes to live inside of those rocks in the lower intertidal zone and it reproduces many times a year. So, great job on taking those observations. I'm super excited, everyone. Woo. You should give yourself a round of applause for completing that first field site. Great.

Maggy Benson:

Where are we going to next?

Vicky Watson-Zink:

Yes. Next, we're moving to a site called the blow holes. So I have a really cool video of this site that I've taken from Christmas Island. It's called the blow holes because as the water is coming in, it rushes through the rocks and it shoots up like a blow hole, like what you'd see in a whale. And so you'll see that in the video in a minute.

A lot of waves back in Christmas Island. It's very noisy. Lots of really sharp rocks. And there's the blow hole. So the way they come is, it shoots water up through the rocks, sort of like a whale. Really funny noise too, coming through it. But there's another blow hole that just showed up on the scene. What a site. And all of a sudden, we hear something sort of skittering down by our feet. I wonder what that is. It's a crab. We found our second crab. So, everybody, meet the mottled-lightfoot crab. So again, we're going to take observations from this crab. First, I just want you to look at the crab and just tell me how you think it looks. Tell me about its leg size, the size of the claws, what color it is. So all your cool observations. I'm really excited to see what comes through.

Maggy Benson:

My first observation is that, this is really beautiful. I love this crab.

Vicky Watson-Zink:

Very pretty crab. It's dressed up for a party.

Maggy Benson:

All right. And maybe while some of our observations come in, you can tell us how Christmas Island got its name. That is Miss Snyder's class would like to know.

Vicky Watson-Zink:

Hi everybody and Miss Snyder's class. So Christmas Island got its name because it was discovered on Christmas by the person that discovered it. They found it on Christmas, so they're like, "We're going to call this island Christmas Island." So, little bit of history there. Have I ever seen a spider crab? Yes, many, and they're really cool. They like to decorate their shells by putting little things on the back so it's harder for predators to find them.

Maggy Benson:

Okay, we have a couple responses here that I'm going to read. Joshua says, it has longer legs and smaller claws. Ariana, it's small. Brantley, yellow and black with red front claws. It looks like a rainforest spider. I love that connection. Looks like a peacock spider and very spooky. Eight legs. So many colors, red, orange, green body. Body looks kind of like a watermelon. Two orange dots in the middle of the back that look like eyes. Interesting. I hadn't seen that until now.

Vicky Watson-Zink:

Yeah.

Maggy Benson:

It looks like it's poisonous because of the coloring. It looks scary. All right, everyone is doing a great job making these observations. Well done.

Vicky Watson-Zink:

Yeah. And so I just want to make a comment about some of these. Someone says something about the number of legs. So crabs are decapods, which means they have 10 legs. And so even though you can see the four walking legs here, the two claws in the front also count as legs, so it has 10 legs. And they do look like spiders, which is actually funny because I'm very afraid of spiders, but I love crabs, so make that make sense. Right? All crabs have 10 legs. Oops. Okay, there we go.

Maggy Benson:

All right-

Vicky Watson-Zink:

Great. Well, great observations on how it looks. So how about we start the poll on how it breathes, what it eats, and how often it reproduces.

Maggy Benson:

All right. Poll will be popping up. And while you're voting on that, Vicky, I have to share that there was one really artistic response there. It looked like these two students made the observation that this crab looked like it was in a paint store during an earthquake in a lot of times. Science does look like art and art looks like science. There is a very fine line, I think, between those two.

Vicky Watson-Zink:

Yeah. And it's very, very beautiful. I love this crab. And another thing I'll say is, it is very big. So if that's my hand for scale, the leg span of this crab is longer than my hand so it has very, very, very long legs. I see the answers from the polls coming in. We got some winners coming out. Let's see what we're doing with what the crab eats.

Maggy Benson:

A couple neck and neck.

Vicky Watson-Zink:

Yeah. So excited.

Maggy Benson:

We'll share with you in a moment. We'll give you maybe about five more seconds. Five, four, three, two, one. All right, well done, everyone.

Vicky Watson-Zink:

Great.

Maggy Benson:

There are some really close.

Vicky Watson-Zink:

Yes, very close. And I can see why it's a little bit mixed because this crab is, we're starting to move up on the land and so things do get a little bit ambiguous in this area when it comes to crab traits. But this crab breathes with its gills. That site that we saw was pretty close to the ocean and so it can still sort of use that water in the ocean to respire. And so this crab still breathes with gills. It's almost a 50/50 split between what people said. This crab eats food from the sea. Those little claws on the front are much smaller than the crab we saw in the first place. It uses that to sort of pluck seaweed off of the rocks. So it eats food from the sea. It also reproduces many times a year, so I can see that everyone got that one correct too, because it's really close to the ocean. So it's in the same area or similar to the area that we saw for the first site, just a little bit higher up, but it's still very close to the water. Great. Great job, everybody.

So, to show our completed field notebook here for the mottled-lightfoot crab. It's a flat crab. It's very, very small so it's really easy for it to fit between the crevices in the rocks. It's fast. So those really long legs are really good for making it run really fast. So they call it the lightfoot crab because it's very light on its feet and has those super long legs for hanging onto rocks and running. It breathes with its gills like I mentioned. Sort of a scavenger that eats seaweeds off of the rocks with those little pincher claws. It lives in the rocks in the upper intertidal zone. And it reproduces many times a year. Just a quick question. Why might it be a good idea for this crab to be a fast runner?

Maggy Benson:

All right, so this is another poll opportunity for you. So we just learned about a lot of this animal's different traits and characteristics and adaptations, but now let's think about how it uses those.

Vicky Watson-Zink:

Mm-hmm (affirmative).

Maggy Benson:

So why do you think it's good for this crab to be a fast runner? Is it to escape predators? Escape the blow holes? They did look a little fearsome. Or race to the beach?

Vicky Watson-Zink:

And just for reference, here's another picture of that site of the blow holes.

Maggy Benson:

That looks like some treacherous terrain. Do you actually walk across those rocks when you are looking for crabs?

Vicky Watson-Zink:

Yes. It is very treacherous, I've definitely gotten a lot of scratches and scrapes from falling on it. And I have to wear rain boots with really thick soles and heels. Or boots ... what are they called? Hard to boots, whatever, to protect myself because those rocks are very sharp.

Maggy Benson:

It looks like it.

Vicky Watson-Zink:

A little bit tricky to navigate.

Maggy Benson:

Knee pads, it looks like would be helpful too in case you fall or need to bend down.

Vicky Watson-Zink:

Yeah.

Maggy Benson:

All right, so we will end our poll. We have lots of responses in and we have a clear winner. In five, four, three, two, one. All right.

Vicky Watson-Zink:

Great job. So everyone who said that they escape predators, that's totally right. So if you look at this site, it's really exposed. And if you imagine a seabird flying by, and you're a crab that's dressed like that in all those wild colors, it's going to be really easy for something to come and try to eat you. So if you're a really fast runner in this area, it's really great for escaping predators. Although I do imagine that they might also use this to avoid getting blown out of the blow holes and so that answer falls so true. And racing to the beach, it's always good to have fast legs if you're trying to get to the beach. So, great job, everybody, on those responses.

So before we move on to our third site, I just want to recap what we've done so far. We found two different crabs, the red-eyed rock crab and the mottled-lightfoot crab. A lot of their biology is similar, but one thing that we notice is that they look different. Their claws are different sizes, their legs are different length. And that's to help them adapt to their particular environment. We also noticed that they eat different things depending on that claw morphology, again, and where they're located. So the red-eyed rock crab crushes snail shells, and the mottled-lightfoot crab uses its little claws to pick off seaweed. And then they live in slightly different areas. One is in the lower intertidal, very, very close to the water, and one is in the upper intertidal, a little bit more distance. So I just want to pause here for a couple of quick questions, if anybody has any questions that they have.

Maggy Benson:

Yeah, we do have a couple questions, and a couple different people have asked just similar questions, including Joshua and Kelly. In that first crab, we saw that one claw was bigger than the other. Can you tell us again why is one claw bigger than the other?

Vicky Watson-Zink:

Yes. The claws have different purposes and so we see this a lot in other marine animals that have claws, where one claw is used for defense or for crushing and one is for pinching tiny things. And so it's because each claw has a different function. I also see a question here about molting. So crabs molt to get bigger. For those that don't know, they would shed their hard exoskeleton. So they're dropping their suit of armor, they pop themselves up with water, and then they get bigger. And that's how crabs get bigger. How often do they molt? They tend to molt more frequently when they're younger because they're a smaller size, but as they get older, they slow down how frequently they molt. And that's just because molting can be a little bit dangerous. Some crabs lose limbs, some crabs don't survive the molt. And so as you get older, it's more risky to molt, as you're reaching your maximum size.

Maggy Benson:

And-

Vicky Watson-Zink:

I have never seen a yeti crab in person. Someone asks if I've seen a yeti crab. Those are really cool. They have these really long, furry claws. I've never seen that, but I would love to. How old can-

Maggy Benson:

You'll have to travel to the deep sea.

Vicky Watson-Zink:

Yes, they're very, very deep. I see a question here about crabs being endangered and how old they get, that I will get to at the end of the presentation because I have a really cool crab to introduce you to.

Maggy Benson:

Okay, let's just take one more. Are crabs herbivores or omnivores?

Vicky Watson-Zink:

That's interesting. I might actually get through that through the presentation too. It varies. So the crabs that live in the ocean tend to be more, we call them, the detritivores. They eat whatever they can get their hands on, so dead animals, plants. But as you move further onto land, the crabs do tend to become herbivorous and they tend to eat more plant matter.

Maggy Benson:

Oh, I actually do want to ask a couple more questions. We got a couple more really good ones that came in. And before we move on from the mottled-lightfoot crab, this is from Megan, why is it beneficial for the mottled-lightfoot crab to be smaller? Perhaps smaller claws.

Vicky Watson-Zink:

Yes, that's a great point, why the body is smaller. So they are found in between those little rocks in the blow holes. Those little crevices tend to be pretty small. Am I lagging? I'm not sure. Anyway, those crevices tend to be a little bit small and so in order to fit its body between those holes when it's trying to escape predators, it makes more sense for that crab to be very flat because it'll be easier to fit into those little niches.

Maggy Benson:

And one more question. It looks like your audio did catch up to you so I think we're back on track. But this comes from Cedar Grove High, how long have you studied crabs?

Vicky Watson-Zink:

I've studied crabs since 2013, so almost 10 years now. I started studying them after I graduated from college. I worked at the Scripps Institution of Oceanography in San Diego, and that's where I fell in love with land crabs. And it's been done and dusted for me since then because they're just so cool.

Maggy Benson:

All right. So Vicky, do we have another field site on our agenda?

Vicky Watson-Zink:

We do. We're moving to our third field site. And again, I have a cool video here to show you of that third field site. So we're heading to a white sandy beach. So here is the video of that site. You can see this nice white stand. There's lots of wave action. You can see little fish sort of darting around in the water here. Great piece of sands.

Maggy Benson:

I want to be there now.

Vicky Watson-Zink:

Sounds really relaxing. I wish I was there too. You can hear a bird and so that might make you think a little bit about predators. The food might make you think about what these animals might be eating, their prey. This beach is called Ethel Beach on Christmas Island. Very, very beautiful site.

Maggy Benson:

And you can see that it still has some of those really sharp rocks surrounding it.

Vicky Watson-Zink:

Yes. Yes. Lots of bird action. Great. So here's just a segment picture of that site. So, very, very calm, very peaceful. We do see a lot of those sharp rocks in the corners here. But at the corner of my eye, I see something scuttling off to the left. What? What? What is that? Oh, we found our third crab. Look at this crazy dude. Those wild-

Maggy Benson:

This is wild.

Vicky Watson-Zink:

Eyelashes. And we found it-

Maggy Benson:

What is going on?

Vicky Watson-Zink:

It's like hanging out near this hole on the ground that we think it's dug. So let's take some observations about this wild looking crab. This is the horn-eyed ghost crab. So those little things are called horns on its eyes. So tell me really quickly what you think this crab looks like. You can think about the color of the crab, think about how the claws look and how they're shaped. You can talk about the legs, whatever comes to your attention. So let's see what you can observe.

Maggy Benson:

It looks like he just went to a disco party. All right. What else? What do other people think about this crab? What are some of your observations? Those horns are wild.

Vicky Watson-Zink:

Yeah.

Maggy Benson:

Sandy colored, big claws.

Vicky Watson-Zink:

Perfect. Sandy color, that's a really good observation.

Maggy Benson:

A very built structure. That's very... It has eye horns. Eyes on stocks. Blue green with gold joints. One claw is larger than the other. It's tiny leg and claws. Ooh, it has strange bumps on its arms, kind of like goosebumps.

Vicky Watson-Zink:

Cool. Cool. I love these observations. I'm just thinking of all the cool things you're observing.

Maggy Benson:

Bumpy texture. That's come in a couple times. Bumpy, bumpy texture. Well done.

Vicky Watson-Zink:

A grasshopper with a cat's mouth. So crabs' mouths are really weird to look at. If you ever seen a crab eat, which I'm sure maybe you haven't, but it's looks so funny.

Maggy Benson:

It's kind of-

Vicky Watson-Zink:

Yeah.

Maggy Benson:

Yeah.

Vicky Watson-Zink:

They're very, very weird morphology and that's because crabs are cool. Those little things, those mouth parts are actually modified legs that they just have in pairs, that they used to eat. It's very alien like.

Maggy Benson:

We have another person who has observed that it looks like a grasshopper. They do have a common ancestor. They're both arthropods. They both have exoskeletons. Green skin. Maybe it comes out only at night because it's a ghost crab. Mr. Crab eyes. All right. And it looks mean.

Vicky Watson-Zink:

Yeah, he looks a little mean.

Maggy Benson:

Those are a lot of really wonderful observations, everyone.

Vicky Watson-Zink:

Great. And a few that I just want to bring to the top here. So a lot of people mention that it's very bumpy. So these crabs do something really cool. The word is really big. It's called stridulation where they can actually rub their claw in different parts of their body as a way of communicating. So those bumps are actually important for this crab. We also mentioned, the color of the crab is sand colored. So again, thinking about camouflage. It's going to be really hard to see this crab against the sand because it's very close to the color of the sand. Very good observation.

Maggy Benson:

All right. So are we ready to make our next set of observations?

Vicky Watson-Zink:

Yes. Let's go to our next poll.

Maggy Benson:

All right, we are going to make our predictions about how it breathes, eats, and lives. This crab that makes a burrow in the sand. And you will be able to vote in just a moment.

Vicky Watson-Zink:

I see someone asking about relatedness. So which other animals are most closely related to crabs? You might think of things like shrimp or lobsters. So again, crustaceans that are in the same group as crabs.

Maggy Benson:

Everybody's doing a great job voting. Compared to the last crab, there are a couple clear front runners.

Vicky Watson-Zink:

Perfect. Yeah. Yeah, everyone's doing a really great job.

Maggy Benson:

All right, it looks like most people have voted so we are going to go ahead and close the poll in about five, four, three, two, one.

Vicky Watson-Zink:

Great job. I think all of those answers are really close to being right. Okay, so about the respiration questions. What do they breathe with? This is a bit of a trick question. So these crabs are really cool because they actually breathe with both gills and lungs. And so depending on like where they are, they can switch back and forth between what they're breathing with, which is really unique. So they're sort of sitting in the middle of using their gills and then the crabs that use their lungs. So very, very interesting adaptation we see in these crabs. It likes to eat food from the sea. Correct. It's very, very close to the beach. So most likely, it's a beachcombing scavenger, it'll eat whatever it finds on the beach. And how often does it reproduce? Many times a year is correct because they're very close to the water. So great job with that, everybody.

Let's show the completed field notebook for this site. So for the horn-eyed ghost crab on site three, we can see that they're sand-colored and they have shovel-like claws. I saw that there was a question in the chat about what they used to dig with. So they use that shovel-like claw in the front that sort of looks like a scoop, like a little spoon, and then they push the sand out of the way.

Maggy Benson:

And Vicky, that's a great point about why we make these observations because we kind of look at the form of the body to figure out the function. Right? You kind of look at that shape to be able to figure out how that animal might be using it.

Vicky Watson-Zink:

Yes, and it all works together. So these crabs adapted to the habitats that they use and the behaviors that they use every day to survive in their habitat. They breathe with their gills and their lungs. Like I said, it was a beach-combing, scavenger. It lives in the burrows that it digs on sandy beaches. And it produces many times a year. So great job, everybody, on site three.

Maggy Benson:

Now, before we go to site four, we did have a question from Megan, that wanted to know how easy it is to find the kind of car crabs that we've looked at. So if you were doing an expedition on site at Christmas Island, would it be really hard to find these three crabs?

Vicky Watson-Zink:

They're all over the place, especially the horn-eyed ghost crab. You can just stand on the beach and then they just are skittering around everywhere. Because they're really, really fast and they're sand-colored, it's a little bit trippy to watch that happen. The crabs that live in the intertidal are very easy to find. And then, again, with the light-footed crab, there's a whole bunch of them on the rocks and so they're kind of all over the place. Very easy to find.

Maggy Benson:

All right, great questions, everyone. Keep them coming. All right, should we move on to our next field site?

Vicky Watson-Zink:

Absolutely. So now we're going into the coastal forest. So, one of our more terrestrial habitats. This is just a picture of the forest floor, and you might see every so often that there are these little red dudes kind of in the leaf litter. What? What are those? And we take another look over here. Are those crabs? Just take a closer look at that guy. Boom.

Maggy Benson:

I mean, of course.

Vicky Watson-Zink:

One of the stars of our show. This is the Christmas Island red crab, and these crabs live in the coastal forest among the leaf litter. So let's just take some quick observations about what this crab looks like. And one thing you might note is that, because it's this really bright color, we were talking a lot about camouflage already, do you think this crab cares anything about camouflaging? If it's-

Maggy Benson:

It certainly doesn't seem like it. It looks like a tomato. It is red. You cannot miss that.

Vicky Watson-Zink:

Very, very bright red.

Maggy Benson:

All right, so make some observations. Again, we are looking at color, which on this one is pretty obvious if you can see that color. We're also looking at those claws, the legs.

Vicky Watson-Zink:

What's it got in its mouth, maybe that'll tell you a little bit about what it might eat as a hint.

Maggy Benson:

All right.

Vicky Watson-Zink:

Medium rotten tomato.

Maggy Benson:

"Red, no camouflage," says Hannah.

Vicky Watson-Zink:

Yep.

Maggy Benson:

Bright red with dark coloring on the top two big front claws. That's a good observation. This one seems to be about similar. Smooth and shiny texture, looking at that texture again. Cool. Tomato red.

Vicky Watson-Zink:

Looks like a berry.

Maggy Benson:

Equal-sized claws, spikes on lower parts of back legs. Bright, I wonder how they stay safe. Looks hard to camouflage. Look like devil horns. Top is black. There's a couple people who have said it looks like devil horns. Sharp bumps, orange and black. It looks funny.

Vicky Watson-Zink:

Is it poisonous? That's a really good observation. These crabs are toxic to eat. So maybe that's why it's bright red. It's like, "Don't eat me. If you eat me, you're going to be in trouble." It doesn't need to camouflage, so it uses a different way to avoid predators.

Maggy Benson:

Great prediction, Ash.

Vicky Watson-Zink:

Yes.

Maggy Benson:

All right, let's make our next round of predictions and launch that pole so that you can think about how it breathes... Or are we ready for that actually, Vicky? Or did you want to share something else with us first?

Vicky Watson-Zink:

Oh no, no, this is ready for the poll now.

Maggy Benson:

Okay.

Vicky Watson-Zink:

Yes.

Maggy Benson:

Great. Okay. Oh, while you're voting on that, Cali commented that it looks like it is eating a leaf.

Vicky Watson-Zink:

Yes. That's a very good observation. Maybe that'll tell you what it might be eating.

Maggy Benson:

Everyone's doing such a great job voting on these polls. And a reminder that, when you're making predictions, even if you don't get it right, it just matters that you kind of think about it and you make a prediction and then you explore kind of how that plays out. It's okay if you don't get them all right. Scientists never get it all right.

Vicky Watson-Zink:

Scientists really know right or wrong. It's just different paths of discovery. And so I've had a lot of my own projects where I'm like, "I think this will happen," then I find that the data supports a different hypothesis. And all that really tells me is that I'm learning more about my system and then it opens up different ways that we can sort of look at what we're learning about the crabs. And so, yeah, any answer here is completely awesome.

Maggy Benson:

Okay, we have a couple of more clear winners here. It looks like most people have voted.

Vicky Watson-Zink:

Yeah.

Maggy Benson:

So we will close this poll in three, two, one.

Vicky Watson-Zink:

Wonderful, great job, everybody. So everyone who guess that this crab probably breathes with lungs is correct. So these crabs live in dry burrows in the forest. They're quite far from the ocean. And so instead of using those gills, which like I said are not very useful on land, they do tend to breathe with lungs. And the picture I showed you of a lung is actually from this species of crab. They do eat food from plants. So this little crab picture gave you a little hint. It's got a little leaf in its mouth. It likes to eat leaf litter, berries, roots, things like that, from plants. And it's almost completely herbivorous. And it does reproduce once a year. Because it is a land crab, it's quite far from the ocean, it will take a lot for it to have to go back to the ocean to reproduce. So it only happens once a year, and these really... I don't want to give way too much there.

But let's look at our completed field notebook for this species. Okay, so again, for the Christmas Island red crab, it's bright red and black. It breathes with lungs. It eats leaves and plants. It lives inside of burrows and coastal forests. And it reproduces once a year.

Great. And one thing I did want to tell you about the species is, they do have these really incredible migrations. So one of the wonders of Christmas Island is the fact that these crabs migrate. And so here's a picture of some of those crabs migrating. So each one of these little crabs is a crab that's about this big. And so there are millions of these crabs that go across the island every year, once a year. It's one of the natural wonders of the world that happen on Christmas Island. So if you're ever on Christmas Island on November, December, you will be here for this. And it is incredible. So this is just a park ranger, just trying to control the crabs. We can see that they have a little wall up to help keep the crabs out of the road because people do live on this island, and they don't want the crabs getting run over and so they try to control where the crabs are to keep them safe. One of them-

Maggy Benson:

That's one of incredible. And I'm actually trying to put myself there. I feel like it would also be a little bit noisy with those little crunchy crab sounds.

Vicky Watson-Zink:

Yeah. So they're settling across the ground and everything, it's very noisy, very active, and the whole forest floor is just a moving ocean of red crabs. So it's really, really amazing.

Maggy Benson:

So cool.

Vicky Watson-Zink:

One of the most amazing things they do on this island to keep the crab safe is they've built this amazing bridge that goes across the road, so the crabs are safe. And so, again, they have these walls that sort of fumble the crabs up the bridge. The crabs, because they have the really sharp claws and feet, they can sort of move up the side of this bridge and then come down on the other side and continue on toward the ocean. So just as a question, why do you think these crabs are... Oops, I think I lagged. Okay, why do you think these crabs are migrating? Where are these crabs going?

Maggy Benson:

Okay, so this is another poll opportunity. So, what are they doing? Why are they migrating? You can tell us in the poll. We'll pop that up. And there we go. So you can vote and tell us in the poll. And while you're doing that, I wonder if we can also think about, there's a couple questions in the chat, about why there's so many, and if they have any predators, thinking about just that volume of crabs.

Vicky Watson-Zink:

How do crabs hear? And if they do, where are their ears located? That's a very interesting question. I guess some crabs can feel vibration through the floor and then there's an organ in their legs that they can use to feel that. I'm trying to think if they actually can. That's a really good question.

Maggy Benson:

That's a good thing to look up when we're done here.

Vicky Watson-Zink:

Yeah, exactly.

Maggy Benson:

Okay. We have a lot of responses in. We're going to go ahead and share those results in three, two, one. All right. We have a clear hypothesis, Vicky.

Vicky Watson-Zink:

Whoo. And you would be correct. So these crabs are moving to the ocean to reproduce. So like I've been saying, a lot of the crowds that live closer to the ocean can reproduce many times a year because they're close to the water, but these crabs actually have to leave their burrows in the forest, walk all the way back to the ocean to reproduce. And they drop their eggs in the water, the eggs develop, and then little itty-bitty baby crabs come back on shore. So great job with that answer. They are migrating to reproduce.

And to show you the opposite, I guess, I call it the reverse migration of the young crabs coming back up into land. So these are baby crabs. So imagine that each of these crabs is like a little grain of rice. There are billions of baby crabs here in this one picture. So after they complete development in the ocean, they come back up through the intertidal, and then they just cover everything with red, the little baby crabs, as they're coming back up onto land as land crabs. Very, very impressive migration in both ways, with the parents leaving the forest, and then the young, a month later, coming back up out of the water to start their new lives as land crabs. Here's another picture of that. And it's just impressive.

Maggy Benson:

Carpet of crabs. Yes.

Vicky Watson-Zink:

They go everywhere. There are people who live on the island, they find these crabs like in the air conditioning vents in their cars. They get into the houses. Because they're very tiny, they can get in all sorts of weird places. But yes, it's a very, very impressive migration of these crabs, that had to come up with a really unique way of reproducing now that they're on land. So, very, very cool.

Maggy Benson:

Now, Vicky, we have about eight or nine minutes left, and I'm wondering if you can just answer a couple questions about these before we move on to our final crab, which somebody's asking how long this migration lasts. Once they get to the sea, how long is it when the adults get to the sea and then these babies get to the forest?

Vicky Watson-Zink:

I want to say it takes about three months total. So maybe it takes a month for the adults to get to water, a month for the babies to develop in the ocean, and then a month for them to come back up on the land. So maybe about a three-month time period. So, very, very impressive.

Maggy Benson:

And Mrs. Lou's class wants to know if it's true that the mother crabs eat their babies.

Vicky Watson-Zink:

They can. So if there's an adult crab in this area, this is basically just food for them. And that's not great to hear, but life, I guess.

Maggy Benson:

Right. Now, from Robin, do these crabs die after reproducing? We know some animals, like salmon, do that.

Vicky Watson-Zink:

No. So the adults crab, once they finish reproducing, they just walk back to their burrows in the forest, and then they do the whole thing over the next year. So they don't die after reproducing. They just produce lots of eggs, they drop them in the water. And then after that, they come back to their burrows.

Maggy Benson:

All right. And why don't these crabs dominate the forest, seeing so many of them?

Vicky Watson-Zink:

They kind of do, especially in Christmas Island. These crabs are all over the place, especially if you go to a place where there are a lot of burrows. So near the blow hole site that we saw before, there's a forest that's just every foot and a half, there's a burrow with a crab in it. So they kind of are all of over the place. When it rains, they all come out their burrows and they can just be really a spectacular thing to see.

Maggy Benson:

Okay. And one final question before we go onto our final, really charismatic crab is... Oh, did I lose it? What part of them is poisonous?

Vicky Watson-Zink:

Oh, interesting. I think it's just the tissue part. So maybe something in the muscles, or maybe part of the internal structure inside of the crab body, the carapace. Yes, so they're definitely not good to eat, for us anyway.

Maggy Benson:

Yeah. Stay away. All right, so let's go to our final crab. We just have a couple minutes left in. If anybody does have to drop off early, I do want to remind you that there will be a survey that pops up in your browser window once you exit Zoom today, and we would really appreciate you filling out that survey about your experience during today's program. But for now, let's go to our final field site.

Vicky Watson-Zink:

Great. So our final field site is the tropical jungle. And so this is just what the jungle looks like on Christmas Island, lots of really weird plants with very long roots. And as we're walking along this tropical jungle path, we see this weird animal on the tree here. What is that? Let's take a closer look from a different angle. Wait, is that a crab? Okay, I'm just going to very carefully take this crab off the tree so we can take a closer look at it. And boom, this is a coconut crab. This is probably one of my favorite species of crabs.

So, coconut crabs are really special. They like to live on tropical islands. So every blue circle here is a place where we've recorded coconut crabs living. So they like the islands. They like living in the tropics. And they're sort of spread all the way throughout the Indian Ocean and the Pacific Ocean, the Western Pacific Ocean. So they're kind of all over in the tropics.

But one thing that you might not know about coconut crabs is, they are actually really big hermit crabs. And so I just have a coconut crab here on the left and then another hermit crab here on the right. And I just want you to very, really quickly spot the difference between these two crabs.

Maggy Benson:

I think I can see a really clear difference. I think with our time, we'll go ahead and call that out. That there is a shell.

Vicky Watson-Zink:

Shell.

Maggy Benson:

Yes, exactly.

Vicky Watson-Zink:

Yes, so coconut crabs are really big hermit crabs, and they get to this size because there's no snail shell that gets to be big enough to hold a coconut crab. When they start out as babies, they do live inside of a snail shell, like other hermit crabs. But then eventually, they get so big and so they just harden the part of their body that would live inside of the shell and then just start getting big. And so they're one of the biggest terrestrial arthropods on planet earth. So very, very special crabs. They live until they're 70 years old. They have these really massive claws on the front that they used to tear open coconuts. Maybe I'll skip this video for time, and then we'll move on to the observation part.

Maggy Benson:

All right. And I just want to emphasize something you just said, that these crabs lived to 70 years old. That is wild.

Vicky Watson-Zink:

Yeah. And so sometimes I'll be handling a really big crab and I'm like, "This crab is probably older than I am." So they're very, very impressive animals. So very quickly, we're going to take some notes about this crab from our last field site. So again, this is a coconut crab. So again, I want you to describe how it looks or just think about how it breathes. What does it eat? How often does it reproduce? Or maybe in the interest of time, I'll just show you the answers.

Maggy Benson:

Well, we can do that, and let's launch our final poll at the same time so that we can give everyone a chance to be field assistants for Vicky one last time. This is our last crab of our expedition, this crazy coconut crab. So you can vote in the poll and use the chat to tell us what you think about how it looks.

Vicky Watson-Zink:

Perfect.

Maggy Benson:

It looks like a turtle. Hard, has a hard shell.

Vicky Watson-Zink:

So I'm seeing a lot of really good answers here. So yes, they like to eat food from plants. They reproduce once a year. They also migrate. And they breathe with lungs. So I'm seeing really, really clear cut winners here. So great job on all of that. It's very big. Yes, they get very big. Their legs span can be up to a meter long, so very big crab.

Maggy Benson:

It looks like, seeing all of these responses, that all of our friends who have viewed today have really, truly understood all of the different kind of adaptations that these crabs have. And you've been able, by the end here, to be able to really quickly figure out these different adaptations. So well done, everyone. I think you all have a future as a field assistant and crab scientists along with Vicky.

Vicky Watson-Zink:

Yeah. And so just going through, they're really big crabs. They move really slow. They have really strong claws. They breathe with lungs. They eat fruits, coconuts, anything tasty. So when I was cooking food out in Christmas Island, I would often hear them climbing up the gate outside the kitchen and try to get in because they have an amazing sense of smell. They like to live in rocky caves or burrows, and they reproduce once a year and migrate.

So I just want to thank you all. Oops. Yeah. Okay, sorry. I lagged. Thank you all so much for helping me as my field assistants today. I've loved all the observations and all the questions, and I want to congratulate everybody on finishing our very successful field trip to Christmas Island. So just go ahead and give yourself a round of applause for all of your hard work.

And then to recap really quickly. We went to five different habitats and found crabs in each place. We used our observational skills and learned a lot about each species, specifically how each one is specifically adapted to its habitat. We learned a lot about those adaptations and about migrations. We saw that as the crabs get farther from the ocean, a lot of their biology changes to help them live on land. And thinking back to that first poll about what crabs use water for, we can see that a lot of these adaptations have changed because the land crabs have less access to water or they're further away from the ocean. So that's really important in the work that I do and understanding how the crabs adapt to land.

So you all should feel so proud of yourself because today, you did something I do every day as a scientist. So great job. And it's been really amazing having you as my field assistants. So go out into the world and make your own observations. And goodbye, Christmas Island. This is a picture of Christmas Island from the airplane window. So unfortunately, all of the great field trips must come to an end. So as we look out at Christmas Island, let's just remember all the cool things that we learned. And if any of what you learned excited you, maybe one day when you're older, you can be a marine biologist too. Yay.

Maggy Benson:

Yay. Oh, and look at that. Vicky, this has been such a fantastic expedition to Christmas Island. I learned so much. You've answered so many questions throughout this program. And we want to thank all of our friends for sending all of those wonderful questions and observations. And even some actions. We have some friends that actually said that one class lives in Puerto Rico, and they're going to go out and explore their island for crabs. So, thank you all so much for joining, sending such a great questions, and making such great observations. And Vicky, thank you so much for being here today.

And I do want to tell everyone that's still on... Oh, I'm going to launch a final survey for anybody that is still here about how you enjoyed today's program. So I'm going to... So tell us what you think about this. And I do want to mention to everyone that we are working on a couple of resources about Vicky's land crabs. So when we follow up with our recording of this program, which we will email to you, we'll send a couple of extension worksheets and posters so that you can learn about crabs a little bit more in your classrooms. So thank you for that, Vicky.

Vicky Watson-Zink:

Awesome. Thank you so much again for being my field assistants. Once I get started talking about crabs, it's hard to shut me up. I just love them so much. So thank you again for your participation.

Maggy Benson:

All right. Well, thank you all so much for being here. Thank you, Vicky. We will be back here on Smithsonian Science How next we week at the same time, Thursday, 1:00 PM where we explore plant respiration, how trees breathe, and how forests and climate change, how those are all connected. So we hope to see you then. For now, we are signing off. Thank you so much, Vicky. Thank you friends. Thank you to our ASL interpreter. We appreciate all of you and all of the educators behind the scenes who made this program happen.

Vicky Watson-Zink:

Thanks, everyone. Bye.