Good morning, John. Recently, I got extremely lucky and was invited for a behind-the-scenes tour of the Denver Zoo. As it turns out, the Nightkeeper of the Zoo, and yes, that's a real thing, is a huge nerdfighter. Like, huge, huge was wearing a nerd-con-nerd fighter ya hoodie and had your face on her shoelaces huge. Basically, we're everywhere, including at the zoo, at night. And I learned so much on this tour that I would now like to tell you the top 17 coolest things that I learned on my behind-the-scenes tour of the Denver Zoo in no particular order. John, elephants can get tuberculosis, the same kind that people can get, so people can give it to elephants, and elephants can give it to people. Sumatra, which I don't think very much about, is the sixth largest island in the world and has its own elephant and tiger and orangutan that exists there and nowhere else. This fish, and I took this video, got a CT scan because it was listing to the side and no one was sure why it turns out it had gas, like intestinal gas. Now, whenever it starts to go sideways, they feed it some peas, and that fixes it. Penguins love to chase flies. Some rhinos are from areas of the world with very little iron, so rhinos that live a long time in other places that don't have very little iron will eat like the grass and other stuff that grows in their enclosures, and that will result in like the opposite of anemia. They have to keep this beautiful man on a low iron diet, but sometimes his iron levels will get too high, and when that happens, they have to take the iron out of him, literally by just removing a bunch of his blood. Oh, it's just dirt. There are fresh water stingrays. The Denver Zoo has a walk-in freezer full of antivenom, and actually serves as a local supply and national supply, because sometimes people get bitten by their exotic pet snakes, and then they call the zoo up, and they're like, do you got one of those? And then the zoo just like gives them their antivenom for free. Like if there's like rules where you can't sell it, so they have to give it away, and then buy more for themselves. That's not one of the reasons why I thought it would be good to have zoos, but there it is. Adult Lake Tidikaka frogs do not breathe. They have little lungs inside of them that are atrophied and never used. They breathe 100% through their skin. They look like that. I mean, they're kind of cute, but also kind of not. Also very strange, possibly because they look a little bit like certain parts of the male anatomy. They get like blended up and drunk as smoothies to increase health. It doesn't work. The Denver Zoo had a king cobra that got cancer. Scale cancer, like skin cancer of a snake. They biopsied it, confirmed it was cancer, did surgery to remove the cancerous area, and then gave adjuvant chemotherapy. Actually, a chemotherapy drug that humans also get, except humans don't usually have it put inside of a rat before they take it. Wild sheep and goats often live in areas without minerals in the soil, and so they will congregate in parking lots to find the salt transported either on cars or left behind when people pee, because as we once learned, they crave that mineral. I have been told that flamingos are pink because they eat pink shrimp, but that's kind of wrong. These are two different species of flamingos that are fed the exact same diet, and one is way more pink than another, and juveniles are basically not pink at all. They are not pink because they eat shrimp. They can be pink because they eat shrimp. They could just poop out the pink compounds. They're pink because it's evolutionarily advantageous to be pink. Friswalski's horse is not pronounced like that. It's pronounced shavalski's horse. The shavalski's horse is the last surviving species of non-domesticated horse. It very nearly went extinct, but was brought back through captive breeding programs, and now they are once again roaming Mongolia. Also, it was part of that effort, a shavalski's horse embryo was implanted in a domesticated horse and was born and is alive and is named Kurt. It is in San Diego, which that sounds great. This is actually raising hopes that we might one day be able to bring back species that are extinct, but have close living relatives like black rhinos. Male elephants have a hormonal cycle, and that leads to something called must. And when they are in must, they're super angry and irritable, in part because glands swell up on the sides of their head until the stinky oils start oozing through their thick skin, which we think probably hurts quite badly. Every year, this boy-vulture, who was raised in captivity, built a giant, beautiful nest. And then, this female-vulture, who was rescued from the wild with a broken wing, very deliberately lays her egg in a tiny pile of sticks a few feet away. I didn't learn anything new about giraffes, because most of the time I had no idea about giraffes, but I did get to touch one and feed it and be really close to it, and that was amazing. Thank you so much to everybody at the Denver Zoo, who took a little bit of time to talk with me, people who are working all across the world doing conservation efforts and trying to make life easier for animals, and especially to Disa and Eric up for it, showing us around. John, I'll see you on Tuesday. Also, the first issue of our new newsletter, we're here, went out today. I hope people like it. There's lots of opportunities to email us through the newsletter, share stuff with us, be collaborative. We do not want this to be like a one-way newsletter. This is going to be a every-directional newsletter. And among the many things we talk about in that newsletter is John, your new video on tuberculosis. It's on the Crash Course channel, an entirely new Crash Course format, where we give somebody a chance to give a lecture. John, you're just the giddy pig. I'm looking forward to seeing who comes next. It won't be me. Though I do want to do one. Tacking this out of the end, because we just sent out the newsletter. So if you want to check your email for it, if you don't see it, you can check your spam folder or just search for Hank and John, or wearing your inbox. I think it's the title of the email. And then you can reply to that if you want to. And we will get that email if you reply to it. Because if you reply to it, your spam filter will be kinder to it in the future. Okay, bye.