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I can't believe the giraffe drought has lasted this long!!

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How many species of Giraffes??">

Giraffes and their Noises">

Giraffes and the Grandmother Hypothesis:">

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Giraffes and Blood Pressure:">

Giraffes and Herding Peoples


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Good morning, John.

The year was 2007 and I put a picture of giraffe in the thumbnail of a video. It was actually just an image from a book I had—I bet I have still have the book actually. It was this book: Birds & Bees, and the image was this one. Just a couple of giraffes having a time. 

Back then in the way YouTube worked, you didn't upload your own thumbnail, it just chose the exact middle of the video. And I, intentionally, held that picture at the exact middle of the video and yeah, it got alotta views. That was followed up by a song in 2008, giraffe love questions in 2009, a complete introduction to giraffe sex in 2010, and then in 2016, it's more discussion of how giraffes mate. But it has now been more than seven years since we last discussed giraffes on this channel. It's the longest giraffe drought we've ever had. And I have the thought, "It's been such a long time, we must have—as a species—found out new things about giraffes since the last time I posted a giraffe video." And guess what, John? It's true. There's a bunch of stuff that we now know about giraffes that we didn't know when we last made a video about giraffes. In preparation for this video, I even got to email a giraffe scientist who is researching giraffes right now in Tanzania, finding out things that we don't know about giraffes. So I'm gonna hit you with five things that we didn't know about giraffes in 2016, but we know them now.

Starting with how many species of giraffes there are. This is a bit of a cheat fact because we still don't know how many species of giraffe there are. Also we kind of can't know how many species of giraffe there are because species is-is like a human idea, not something that nature does. But look, giraffes are spread out. They exist all the way from just south of the Sahara to South Africa. That's a bigger distance than you'd think. New York and London are closer together than giraffes. You, John, are closer to Brazil than West African giraffes are to South African giraffes. But, a series of whole genome analyses show that we probably should not be considering giraffes to be one species. There might be three, there might be four, there might be five, there might be six. But that conversation is super important because if you count all giraffes as just giraffes, then there's like hundreds of thousands of giraffes. But if you divide them up into four different species, then some of those species are very endangered. 

Now in 2016, we also didn't think that giraffes really vocalized. At least not much. Some people even thought that, like, their necks were too long for them to make vocalizations. They'd make noises. They'd do like coughs and snorts and snuffles, and they do lots of different communications with their heads and bodies. But it was in the last seven years that we realized that giraffes do vocalize. They just do it at night, often, and in a very very low-pitched hum, which is an amazing noise that I do not have access to the copyright of, but I will link it in the description. It's a beautiful noise that you can barely hear with the human ear, and these vocalizations are part of how giraffes communicate and maintain their culture.

And that's another thing that we've learned since 2016 is giraffes are intensely cultural and much smarter and more social than we thought. And one key thing here is something that they actually have in common with people and something that is very rare in the animal kingdom. Giraffes have females that continue to survive for a long time after they no longer are able to breed. Like 30% of the lifespan of a female giraffe is after it is capable of making babies. We see post-reproductive female in not very many species. Humans, killer whales, some other kinds of whales like pilot whales I think, kinds of elephants though people will argue about elephants, and now giraffes. The reason we think this happens is called the grandmother hypothesis. It's that it happens in species where information transmission from older to younger generations is really important. So like cultural information, like knowledge and understanding and, like, it needs to have a repository in older members of the social group so that the younger members can benefit from that. That indicates that giraffes are much more social and much more cultural and have much more knowledge than we thought they did.

Alright, big shift now because it's time to talk about blood pressure. Giraffes, as you might expect, have very high blood pressure because they have to get the blood to where it needs to go. Like high enough blood pressure that if it was your blood pressure, it would damage your heart to be pushing blood that hard. And so researchers were like, "It'd be nice if we figured out what's going on with the giraffes. Maybe we could help, uh, people not get damaged hearts if they have high blood pressure, maybe?" And they actually found a gene in the giraffe that seems to be responsible for some of their heart's resilience, and they took that gene and they put it into mice and then they gave the mice high blood pressure artificially. And the ones who had the giraffe gene experienced way less scarring of their heart when they had high blood pressure, so that's wild. I don't know what we're gonna do with that, but that's wild.

And finally, as we understand how remarkable giraffes are, how much more social they are, and also that there are a lot of species of them, and also that they're losing a lot of their habitat, and their population is decreasing quite quickly, the conservation of giraffes becomes even more important. Now it used to be imagined that wildlife and people who herd animals kind of exist in opposition to each other. And that is definitely true to some extent, like this relationship is extremely complicated. But it should also be noted that people have been herding in sub-Saharan Africa for many millennia. And so recently, there's been a lot more research into not just the antagonistic parts of the herder-to-wildlife relationship, but also the parts where actually the herding people might be in some ways good for the savanna and for the wildlife. And certainly when compared with other land uses like farming or mining or charcoal production, herding is much less impactful to the savanna and to the wildlife populations. And so, if you do it right, you can actually see a world where protecting traditional uses of land is actually also good for wildlife, even though we used to think those things were really, like, ultimately strictly in opposition to each other—which I've been reading about in this book called Savannas of our Birth by Robin Reid. It's not the world's greatest clickbait thumbnail or anything, but it is really good and fascinating.

And the thing to remember about all of this information is that people went out and got it. And that is so-it was illustrated by this book which looks quite long, right. And it is. But this part is the book and this part is the notes and references, which that's a lot of references because there's a lot of people working on this stuff! The scientist I emailed with said that a lot of times we miss what giraffes are up to because they do everything so amazingly slowly. But that doesn't mean that we as a species cannot do it. We just need to watch and to listen, especially to their nearly subsonic hums.

John, I'll see you on Tuesday.