Wildlife biologist and host of ABC's "Ocean Treks" Jeff Corwin brings us another postcard from his adventures abroad. This time, Corwin's quest is to fulfill a lifelong dream: finding a Giant Japanese Salamander.
Note: The Japanese Giant Salamander is designated as a Special Natural Monument, and capturing them is prohibited by Cultural Assets Preservation Act. This was recorded when the crew joined the habitat survey authorized by Agency for Cultural Affairs.
Jeff Corwin: For 50 years, this has been one creature that has haunted and I've come to find it here deep in the mountains of Kyoto — in a river known as Kyoto Key, which literally means “pure falls.” And it's in these cold, pristine, highly oxygenated waters where one of the most mysterious creatures lives; A creature I've waited my whole life to find: the giant Japanese salamander.
This river is absolutely spectacular. We have this verdant landscape, these almost Bonsai-like trees are folding, bridging above our heads. There are rapids, cascades, and waterfalls. I'm with Kanto San. He's a professor of biology, a salamander master, with the University of Kyoto, and his assistant, Kanto. This river twists and winds through this remote rocky landscape. The water is cold and it is crystal clear, but surprisingly we're not seeing any salamanders. And that's probably because they're endangered.
Kanto San: Yes. Endangered and threatened.
Corwin: Why are they threatened?
Kanto San: Because humans destroyed the habitat for them, so that they have nowhere to live.
Corwin: And Kanto, these salamanders, they really need healthy clean waters.
Kanto: Exactly. Their skin is very sensitive to pollution, and if there's toxins and bad chemicals in the water they're going to be the first to react.
Kanto San: Yes. Pollution’s a big problem.
Corwin: But the good news today: this river is healthy and supposedly, there are salamanders here, and we need to find them. And to do that, we're going to turn over rocks and look in every hole we find until we discover one of these Giant Japanese Salamanders. All right, let's search.
Kanto: All right.
Corwin: So we're just flipping over rocks like this. A lot of these rocks are pancake-shaped, they're very flat and they're very heavy. And strategically what the Salamander does is he tucks his way under those rocks. He's hidden from predators, but then he becomes the ultimate predator. Kanto, what are these salamanders feeding on?
Kanto San: Fish, crab, and some insects.
Corwin: So we'll continue our search, and hopefully we will find one of these salamanders.
Sound of searching through the water.
Kanto San: Oh. Here! There’s a salamander.
Kanto San: Here. Here. Look.
Corwin: Oh my goodness. Holy cow. So right under this rock.
Kanto San: Yes.
Corwin: It's right there. You can see it. It is absolutely giant. This salamander. It's huge. The salamander is wedged under this rock so I'm going to, Kanto San, put the net in front of the head like this?
Kanto San: And touch the tail – softly. Push it.
Corwin: So I’ve got the net in front of his face. And I'm going to touch the tail, slowly, methodically, he crawls. It's like a hippopotamus with a tail. He crawls his way into the net, and now we’ve got a Giant Salamander.
Kanto San: Yes. Yes. Good job. Good job.
Corwin: Now, what do we do?
Kanto: Next we're going to measure them, weigh them, and then check their microchip tags.
Corwin: OK, so we found our way to the edge of this beautiful stream. And we've got this gray colored pipe. It's actually half of a pipe and it's graduated. It has these different lines, which basically give us the measurement. So we slide the salamander in. And so the measurements here I see --
Kanto: He’s kind of squirming.
Corwin: It's a very squirmy, and it's very slimy. So we're measuring it out. And the tail comes to about 82 centimeters. This is almost a 3 ft. long salamander. The most amazing characteristic about the salamanders is that they have lived on our planet practically unchanged for many many millions of years. Before the age of dinosaurs, these creatures were roaming the waters of the world. But today, there are only three species remaining. We've got the Giant Japanese Salamanders, and where are the two other ones found?
Kanto San: Another from China.
Corwin: The Giant Chinese Salamander.
Kanto San: Yeah. And the Hellbender from U.S.A.
Corwin: In the United States, we have the Giant Hellbender, a salamander like this, but smaller in size — up to 1.5 to 2 ft. in length. Named the Hellbender because they would frighten those folks who discovered it. But this is a harmless creature. It’s not aggressive. It's not dangerous.
Kanto: No. Exactly.
Corwin: So we've got these measurements, what's next?
Kanto: We're going to check for microchip tags that we might have embedded.
Corwin: So we have this wand and as we wave this wand over near the shoulder area this number comes up: 00075a36. Where did that number come from?
Kanto San: This individual we collected last year.
Corwin: You've discovered him before.
Kanto San: Yes.
Corwin: That means for however long this salamander lives – and it could live for how long?
Kanto San: At least 60 years.
Corwin: 60 years.
Kanto San: At least.
Corwin: If science continues and scientists study this creature, they'll always know who he is. And because we have this microchip identification, we can compare the measurements of today with the measurements of before. So we know who this guy is. OK. So we have all the data; we know who the salamander is. What else do you need?
Kanto San: Next we take the DNA samples from the animal.
Corwin: What do you hope to learn?
Kanto San: To identify [if] this is a true, pure Japanese GiantSalamander or not.
Corwin: What else could it be?
Kanto San: Now, many Chinese Giant Salamander in Japan.
Corwin: So today, living in these rivers, the Giant Japanese Salamander is not the king. There are salamanders now --
Kanto San: Yeah, now competing.
Corwin: Competing with Giant Chinese Salamanders. The Giant Chinese Salamander is larger and more aggressive than the Japanese species. How they are out-competing?
Kanto San: They're fighting for nests for breeding.
Corwin: They're fighting for the nesting.
Kanto: They’re very territorial in the breeding season.
Corwin: So during the breeding season, they're very territorial and they're also cross-breeding, aren't they, Kanto?
Kanto: Yeah. In several rivers in Kyoto prefecture, there are many hybrids right now between the Japanese Giant Salamander and the Chinese Giant Salamander.
Corwin: So the challenge for this species and the scientists trying to save it is to keep its genetics pure — as a Japanese Giant Salamander. And unfortunately, with the invasive species Chinese Salamanders out-competing and outbreeding the native ones. How did the Giant Chinese Salamanders get here?
Kanto San: Probably for the food or a pet.
Corwin: People brought them from China as food and pets.
Kanto San: Yeah, imported from China.
Corwin: But today in Japan, the Giant Japanese Salamander, it's protected isn't it?
Kanto San: Yes, so now, very difficult to import. But formerly not protected, so many people imported, I think.
Corwin: Kanto San and Kanto, for over a thousand years the Japanese Giant Salamander has been the fodder for legends and folklore. And some have even argued that this is the original dragon.
Kanto: Yeah. Maybe.
Corwin: And for the people of Japan what place does the salamander hold?
Kanto San: Yes. The Japanese Giant Salamander is protected as a national monument, so totally protected.
Corwin: We normally reserved that for landscapes or places or culture and education and science. What the bald eagle is to America, the salamander is for you.
Kanto San: Exactly, Yeah.
Corwin: Why do you study this salamander?
Kanto San: It's very important for the ecosystem in [the] Japanese River because it’s the top of the food chain. So if we protect [the] Giant Salamander, we can protect all the creatures in the river system.
Corwin: By protecting the Giant Japanese Salamander --
Kanto: And their habitat.
Corwin: — and their habitat, it becomes an umbrella protecting all the species under it. And Kanto, it's also an indicator species isn't it?
Kanto: The Giant Japanese Salamander has a very sensitive skin. Toxins and chemicals in the river will affect them immediately.
Corwin: So in a way, this is a canary in the coal mine for this ecosystem because if the salamander is in trouble, so is the entire living community where it thrives. But the good news today is because of this work, this salamander — this species — is surviving. So we have one last thing to do which is to --
Kanto San: Yeah, we must get back to the nature.
Corwin: Get back to the nature. Before we do that. Kanto San is taking out a scale. What’s that say?
Kanto: 4.93 kg. So that would be a little bit over 10 lbs.
Corwin: A 10 lb. salamander that lived even before the time of dinosaurs. And this is why for me, experiencing the salamander, was checking off a big moment on the Jeff Corwin bucket list. So back to the waters it goes.
Kanto: All right.
Sound of walking through the water.
Corwin: We open the net. And there it goes. Out comes this Giant Salamander back to the ecosystem where it belongs, where it has lived for millions of years — where it has built up the culture of Japan for over a thousand years. Thank you so much.
Kanto San: You're welcome.
Corwin: Thank you. Arigato.
This segment aired on September 8, 2017.