WEBVTT - The Remarkable Beaver, Part 1 0:00:03.040 --> 0:00:06.840 Welcome to Stuff to Blow Your Mind, the production of iHeartRadio. 0:00:13.160 --> 0:00:15.680 Hey you welcome to Stuff to Blow your Mind. My 0:00:15.760 --> 0:00:19.480 name is Robert Lamb, and I'm Joe McCormick. We've covered 0:00:19.640 --> 0:00:23.720 numerous examples of this before. But obviously, in days before 0:00:23.840 --> 0:00:29.120 photography and videography, one had to depend on illustrations and 0:00:29.200 --> 0:00:33.640 written descriptions to convey the reality of an organism, you know, 0:00:33.760 --> 0:00:37.479 be it a bird or a fish, what have you. 0:00:38.240 --> 0:00:41.360 But this is especially true for creatures that lived in 0:00:41.479 --> 0:00:45.400 lands beyond your direct experience. You know, what are the 0:00:45.840 --> 0:00:48.879 what are the mammals, what are the birds? Like on 0:00:48.960 --> 0:00:50.960 another continent. Well, you have to send people out in 0:00:50.960 --> 0:00:52.320 the world. They can, you know, to a certain extent. 0:00:52.360 --> 0:00:54.800 They can bring specimens back. Certainly, they can bring parts 0:00:54.800 --> 0:00:58.600 of specimens back, but it's those illo in some cases. 0:00:59.400 --> 0:01:04.080 But it's those illustrations that really bring things alive. Now, 0:01:04.480 --> 0:01:07.520 certainly there are some fine examples of naturalist illustration out there, 0:01:07.600 --> 0:01:11.160 especially from recent centuries. I mean there's some gorgeous, like 0:01:11.200 --> 0:01:14.520 you say, like Audubond illustrations and paintings that sort of thing. 0:01:15.080 --> 0:01:17.840 But there are also countless examples, and we've touched on 0:01:17.880 --> 0:01:22.399 these before in the show of rougher drawings, drawings that 0:01:22.440 --> 0:01:24.440 feel like, you know, there's been a game of telephone 0:01:24.880 --> 0:01:28.880 at play. And this is especially the case for examples 0:01:28.920 --> 0:01:33.479 found in various bestiaries and medieval manuscripts, among other places. 0:01:33.959 --> 0:01:37.840 And when we think of such misconstrued animals, you know, 0:01:37.880 --> 0:01:39.319 what do we tend to think about? You know, we 0:01:39.360 --> 0:01:43.520 think about the rhino, We think about the lion, the whale, 0:01:43.640 --> 0:01:48.120 the elephant, you know, great animals, apex, predators, and megafauna. 0:01:48.560 --> 0:01:50.880 But in this episode, in the next episode, at the 0:01:51.000 --> 0:01:53.840 very least, we're going to get into another creature that 0:01:53.880 --> 0:01:59.360 has also experienced extreme inaccuracy in historic illustration, and that 0:01:59.520 --> 0:02:03.200 is a common beaver. Based on just some of the 0:02:03.240 --> 0:02:06.640 images we've been looking at, a beaver might well be 0:02:07.080 --> 0:02:10.520 a kind of strange dog or a pig, with perhaps 0:02:10.800 --> 0:02:13.560 a fish tail on its body and a real hybrid 0:02:13.639 --> 0:02:17.800 feeling like it is, almost like it's a strange like 0:02:18.120 --> 0:02:23.400 dog mermaid. It might be in almost all respects a deer, 0:02:23.919 --> 0:02:28.200 like a creature with long legs and hooves, And it 0:02:28.560 --> 0:02:32.560 may also look like a strange and confused rodent with 0:02:32.680 --> 0:02:36.480 a great button seam running down its chest. It may 0:02:36.520 --> 0:02:39.400 even look like a weirdly serpentine lion. 0:02:40.040 --> 0:02:45.080 So Rob has been sharing medieval and Renaissance illustrations of 0:02:45.120 --> 0:02:48.840 beavers with me for a couple of days now, and 0:02:49.200 --> 0:02:51.160 I really do love all of them, but I do 0:02:51.200 --> 0:02:53.000 think the one I like the most is the one 0:02:53.040 --> 0:02:56.639 that's just straight up a deer with hooves, except it 0:02:56.680 --> 0:03:00.680 has razor blades for teeth, just like the rectangular blades. 0:03:01.240 --> 0:03:03.000 Yeah, yeah, this one. I had to go deeper on 0:03:03.080 --> 0:03:05.600 this one because I was it initially came up in 0:03:05.639 --> 0:03:07.799 an image search, and you know, I think it was 0:03:07.840 --> 0:03:09.600 maybe on a Pinterest or something. I was like, I 0:03:09.600 --> 0:03:12.080 can't trust this, but I eventually looked it up in 0:03:12.120 --> 0:03:17.520 the catalog of illuminated manuscripts and it is a Northern 0:03:17.600 --> 0:03:24.000 Italian illustration from somewhere around the year fourteen forty, and yeah, 0:03:24.040 --> 0:03:26.880 it just looks like a It is labeled as a beaver, 0:03:27.240 --> 0:03:29.840 but it is in all respects of deer. So I 0:03:29.919 --> 0:03:33.240 was just really astounded, like here, especially as an image, 0:03:33.680 --> 0:03:38.520 that it not only gets the form wrong regarding the 0:03:38.560 --> 0:03:41.600 target organism, it gets everything about like the energy of 0:03:41.640 --> 0:03:43.800 the creature wrong, you know, cause it's it's one thing 0:03:43.800 --> 0:03:45.680 if you have a depiction of a rhino. That okay, 0:03:45.680 --> 0:03:48.120 it's like a big armor plated thing with four legs. 0:03:48.160 --> 0:03:50.600 It's like, all right, I mean, that's it's an extravagant 0:03:50.680 --> 0:03:54.640 version of the truth. But this it's like, how wrong 0:03:54.760 --> 0:03:56.080 did this game of telephone go? 0:03:56.680 --> 0:04:00.200 Right? With the right you like, with deerors rhinoceros, you 0:04:00.240 --> 0:04:04.800 can see that beginning as a rhinoceros but with embellishments, yes, 0:04:05.280 --> 0:04:07.480 But with the beaver, it's like, oh, I'm sorry, did 0:04:07.560 --> 0:04:10.160 you say beaver? I thought you asked for a depiction 0:04:10.360 --> 0:04:13.880 of a lion with a snake neck biting its own genitals. 0:04:14.440 --> 0:04:16.560 That's right, because and this is this is something we'll 0:04:16.560 --> 0:04:19.640 probably get into mostly in the next episode, but there 0:04:19.720 --> 0:04:24.279 is this pervasive myth that existed for a very long 0:04:24.320 --> 0:04:27.440 time that when pursued by hunters, a male beaver would 0:04:27.480 --> 0:04:29.880 chew off its own testicles. And so many of these images. 0:04:30.360 --> 0:04:33.840 Be your creature more dog or catlike or or or 0:04:33.880 --> 0:04:36.479 actually just a deer with razor sharp teeth, it is 0:04:36.520 --> 0:04:40.840 often depicted g nine at its testicles. That at least 0:04:40.880 --> 0:04:43.480 we have some answers for in the next episode where 0:04:43.520 --> 0:04:45.760 that idea comes from and why it's so pervasive. 0:04:46.279 --> 0:04:48.000 Right, So you've got to stick around for next time 0:04:48.040 --> 0:04:48.520 to hear that. 0:04:49.240 --> 0:04:52.760 Yeah, so let's let's start with what we know. Let's 0:04:52.760 --> 0:04:55.200 start with the reality. We're gonna start by talking about 0:04:55.440 --> 0:04:59.359 just basic beaver anatomy and behavior. And I probably don't 0:04:59.400 --> 0:05:01.960 have to tell most listeners out there what a beaver 0:05:02.040 --> 0:05:05.640 looks like. I mean, for starters, like, we have images 0:05:05.680 --> 0:05:08.680 all over the place of them, we have documentary footage. 0:05:08.720 --> 0:05:12.559 Many of you can go and see a live beaver 0:05:12.600 --> 0:05:15.159 at least in some sort of like a zoo environment, 0:05:15.480 --> 0:05:17.760 or you have seen them in the past. But on 0:05:17.800 --> 0:05:19.760 the other side of the coin, it's like, I still 0:05:19.880 --> 0:05:21.680 kind of have to tell you what a beaver looks 0:05:21.760 --> 0:05:24.080 like because the beaver is kind of in the same 0:05:24.160 --> 0:05:27.040 category as the spouting whale, as we discussed in some 0:05:27.120 --> 0:05:29.600 of our recent whale episodes, that's particularly the ones on 0:05:29.720 --> 0:05:35.520 spouting and spouts. Because despite all this access to actual, 0:05:36.080 --> 0:05:39.320 solid documentary footage of the beaver, we still have this 0:05:39.440 --> 0:05:42.880 rich history of cartoon depictions of beavers that inevitably cloud 0:05:42.920 --> 0:05:44.360 our understanding of the creatures. 0:05:44.640 --> 0:05:46.720 I mean, I think you get a fairly accurate mental 0:05:46.760 --> 0:05:50.080 picture if you just cross a squirrel with a grizzly bear. 0:05:50.560 --> 0:05:53.640 You know, you mash those two up your most of 0:05:53.640 --> 0:05:55.840 the way there. But while that does get you sort 0:05:55.880 --> 0:05:59.400 of the shape the outline, right, that does not tell 0:05:59.400 --> 0:06:01.640 you everything you need to know about beaver's. Beavers are 0:06:01.800 --> 0:06:06.200 much stranger and more beautiful than I realized. 0:06:06.760 --> 0:06:07.000 Yeah. 0:06:07.120 --> 0:06:10.680 Yeah, there's a lot of weird and wonderful aspects to 0:06:10.760 --> 0:06:14.880 their morphology, to their behavior, and a lot of this 0:06:14.920 --> 0:06:18.360 is stuff that our popular conceptions of the beaver don't 0:06:18.400 --> 0:06:20.279 get into. I mean, you know, they do get some 0:06:20.320 --> 0:06:22.159 of the things right. You know, the basic shape of 0:06:22.160 --> 0:06:24.480 the beaver is far better in cartoon than it is 0:06:24.520 --> 0:06:27.640 in many of these eliminated manuscripts. You know, some things 0:06:27.680 --> 0:06:29.880 hold up. Obviously, beavers are not going to sell you 0:06:29.920 --> 0:06:33.720 out to the White Witch. That's absolutely true. So C. S. 0:06:33.800 --> 0:06:35.640 Lewis was right on that count, even if he got 0:06:35.640 --> 0:06:39.440 the whole diet of the beaver wrong, because in Narnia, 0:06:39.440 --> 0:06:42.479 apparently beavers like to eat fish and chips. That's not 0:06:42.600 --> 0:06:45.920 happening in the actual natural world. 0:06:46.520 --> 0:06:48.599 On the other hand, I will say, there is the 0:06:48.680 --> 0:06:51.320 kind of food and organism usually seeks out to eat 0:06:51.360 --> 0:06:54.880 in its environment, versus what an animal will eat if 0:06:54.880 --> 0:06:57.280 given the opportunity. I kind of wonder. I feel like 0:06:57.279 --> 0:07:00.919 if you gave a beaver a basket chips and some 0:07:01.000 --> 0:07:02.839 malt vinegar, I don't know they might get into that. 0:07:03.800 --> 0:07:05.800 All right, Well, let's start with the basics here. So 0:07:05.839 --> 0:07:09.800 beavers are rodents and are in fact the second largest 0:07:09.840 --> 0:07:14.760 extant rodent, surpassed only by the mighty capybara. Beavers can 0:07:14.800 --> 0:07:18.280 weigh up to fifty kilograms or one hundred and ten pounds. 0:07:18.840 --> 0:07:21.480 There are two extant species of beaver. There's the North 0:07:21.480 --> 0:07:27.000 American beaver or Castor canadensis and the Eurasian beaver caste 0:07:27.080 --> 0:07:33.240 or fiber. But the Castoridae family includes some impressive extinct 0:07:33.440 --> 0:07:36.760 species as well. In fact, there were giant beavers that 0:07:36.840 --> 0:07:40.920 lived during the Pleistocene, reaching weights of up to one 0:07:41.000 --> 0:07:43.520 hundred and twenty five kilograms or two hundred and seventy 0:07:43.560 --> 0:07:46.640 six pounds, So that is more than twice as big 0:07:47.000 --> 0:07:50.480 as extant beavers, though I was reading they seem to 0:07:50.560 --> 0:07:55.160 have had smaller brains, among other morphological differences. But yeah, 0:07:55.240 --> 0:07:58.280 so they were bigger, and you know, maybe to some 0:07:58.360 --> 0:08:00.960 extent they didn't have to or at not yet developed 0:08:01.520 --> 0:08:05.240 these very impressive behaviors and abilities that we'll get into 0:08:05.280 --> 0:08:08.600 concerning modern beavers. Now, one note on these guys. They 0:08:08.640 --> 0:08:12.560 were still smaller than the fifteen hundred kilogram or thirty 0:08:12.560 --> 0:08:18.240 three hundred pound giant pacaranas of South America. Extant pacaranas 0:08:18.400 --> 0:08:21.160 only get up to like thirty three pounds or fifteen kilograms, 0:08:21.360 --> 0:08:23.440 and they can still be found in the western Amazonian 0:08:23.560 --> 0:08:27.800 River basin. But the giant ones they were pretty massive. 0:08:28.160 --> 0:08:32.199 A lot of rodents of unusual size in prehistory, all. 0:08:32.160 --> 0:08:35.120 Right, So no beavers today in that territory. But beavers 0:08:35.120 --> 0:08:36.680 can still get pretty chunky. 0:08:36.880 --> 0:08:39.480 That's right. Yeah, they're pretty big. And this is like 0:08:39.480 --> 0:08:43.600 a fact. I frequently forget that they're the second biggest rodent. 0:08:43.920 --> 0:08:45.880 The Caapi bear is easy to remember, but it's sometimes 0:08:45.920 --> 0:08:48.199 it's easy to forget who's coming in second. Now, it's 0:08:48.240 --> 0:08:52.760 extremely important to note that beavers are semi aquatic, having 0:08:52.800 --> 0:08:57.040 evolved to thrive in various freshwater habitats. So a number 0:08:57.040 --> 0:08:59.280 of the things we're going to be discussing about them 0:08:59.720 --> 0:09:02.800 lying up with their habitat. For instance, they can hold 0:09:02.800 --> 0:09:07.360 their breath for fifteen minutes. They have transparent third eyelids 0:09:07.440 --> 0:09:11.040 called micitating membranes to aid them in their swims much 0:09:11.120 --> 0:09:16.079 like manates. They also famously have long, flat, black tails. 0:09:16.120 --> 0:09:19.040 We know this from the cartoons obviously, and these aid 0:09:19.120 --> 0:09:22.040 them and they're swimming, but they can also use them 0:09:22.040 --> 0:09:24.880 to sound an alarm by slapping the water, slapping the 0:09:24.880 --> 0:09:27.480 surface of the water, and they also use them to 0:09:27.640 --> 0:09:31.680 balance when they're carrying wood or other loads across the ground. 0:09:32.720 --> 0:09:34.640 For any of you out there who watch a lot 0:09:34.679 --> 0:09:37.600 of animal videos on Instagram and so forth, you may 0:09:37.600 --> 0:09:43.040 have seen videos of adorable beavers carrying carrots around, and 0:09:43.400 --> 0:09:45.800 if you're not looking closely enough, you might think they're 0:09:45.840 --> 0:09:48.800 dragging their tails. But if you will look closely, you 0:09:48.800 --> 0:09:51.880 can see that the tail is off the ground and 0:09:51.920 --> 0:09:53.080 it's helping them balance. 0:09:53.600 --> 0:09:55.840 One of the things I've noticed about watching beavers try 0:09:55.880 --> 0:09:59.000 to move objects around is how much more gracefully they 0:09:59.000 --> 0:10:01.000 do it in the water than on the land. So 0:10:01.040 --> 0:10:04.320 these are semi aquatic mammals, but I don't know, it 0:10:04.360 --> 0:10:07.040 seems to me that the water is where they're really 0:10:07.040 --> 0:10:10.319 in their element. They can swim fast and gracefully, even 0:10:10.360 --> 0:10:14.840 carrying like an unwieldy branch that's kind of unbalanced or something. 0:10:15.520 --> 0:10:17.360 They do that all quite well in the water and 0:10:17.360 --> 0:10:20.559 then once you see them sort of toddling along across 0:10:20.640 --> 0:10:23.960 the dry land, it looks much more comical and awkward. 0:10:24.679 --> 0:10:26.319 Yeah, and this is going to be important to keep 0:10:26.320 --> 0:10:29.000 in mind when we talk about the amazing ways that 0:10:29.000 --> 0:10:33.920 they transform an environment to better fit their needs and desires. 0:10:34.520 --> 0:10:36.280 Oh but before we get into that, we of course 0:10:36.320 --> 0:10:38.440 have to talk about the teeth of the beaver. This 0:10:38.559 --> 0:10:43.280 is something that is generally an important part of cartoon 0:10:43.360 --> 0:10:46.760 imagery concerning the beaver. A lot of times cartoon beavers 0:10:46.840 --> 0:10:49.640 will speak with a kind of whistle in their voice, 0:10:50.200 --> 0:10:51.880 but we also tend to get it quite wrong. 0:10:52.200 --> 0:10:54.400 Okay, so I'm trying to picture the cartoon beaver. I 0:10:54.400 --> 0:10:57.680 think what we always see is an overbite with two 0:10:57.840 --> 0:11:01.040 kind of square shaped teeth grouped right together in the middle, 0:11:01.120 --> 0:11:05.600 like a person's front two teeth, but large and overlapping 0:11:05.640 --> 0:11:07.440 the bottom lip. Is that about it? 0:11:07.880 --> 0:11:09.000 Yeah? Yeah, pretty much. 0:11:09.480 --> 0:11:11.080 The truth is much more shocking. 0:11:12.440 --> 0:11:17.520 Yeah, yeah, they have these. You know, if you look 0:11:17.520 --> 0:11:20.600 at a skull of a beaver, it's pretty remarkable because 0:11:20.880 --> 0:11:24.680 it's like this, the really kind of exaggerated rodent skull 0:11:25.480 --> 0:11:29.240 with just incredible incisors, you know, with these two big 0:11:29.280 --> 0:11:32.200 shovel like teeth coming down from the top, two big 0:11:32.240 --> 0:11:35.480 shovel like teeth coming up from the bottom, and then 0:11:35.520 --> 0:11:38.800 the rest of the back teeth or much further back, 0:11:38.840 --> 0:11:41.560 you know, giving them some ample room to do the 0:11:41.679 --> 0:11:44.240 kind of a woodwork that they need to do with 0:11:44.320 --> 0:11:45.080 those chompers. 0:11:45.760 --> 0:11:49.360 The skull is a powerful bone hinge, and it's like 0:11:49.520 --> 0:11:54.760 it's like a kind of alien biotechnological set of bolt cutters, 0:11:54.800 --> 0:11:57.280 except the bolt cutters are orange teeth. 0:11:57.960 --> 0:11:59.760 That's right. The orange is key. This is something I 0:11:59.800 --> 0:12:02.800 will almost never see in like a cute c illustration 0:12:02.920 --> 0:12:06.960 or a cartoon depiction of a beaver. So, yeah, these 0:12:07.040 --> 0:12:11.040 teeth have thick layers of enamel which has this orange colorization. 0:12:11.280 --> 0:12:15.720 Because while other rodents boast magnesium enriched tooth enamel, beavers 0:12:15.800 --> 0:12:19.320 have iron enriched enamel. They're like, I mean, it's it's 0:12:19.400 --> 0:12:21.480 like something out of out of a comic book, right. 0:12:22.640 --> 0:12:25.520 The iron makes their teeth stronger against this the pure 0:12:25.600 --> 0:12:28.800 mechanical stress that they put them through. We should also 0:12:28.840 --> 0:12:31.800 note that these teeth continue to grow throughout their lives, 0:12:32.200 --> 0:12:34.040 to the point where they have to gnaw them down 0:12:34.080 --> 0:12:36.640 on trees to keep them down. But yeah, they're just 0:12:36.800 --> 0:12:40.440 super resilient, always growing, and they're also more resilient to 0:12:40.480 --> 0:12:42.719 acid as well based on their composition. 0:12:43.320 --> 0:12:45.440 Just some tough, rusty looking teeth. 0:12:45.960 --> 0:13:03.680 Yeah, yeah, the orange is really quite shyy. 0:12:58.160 --> 0:13:02.079 Okay. Another essential biological aspect of the beaver before getting 0:13:02.080 --> 0:13:05.520 into their behavior is that they have a cloaca. So 0:13:06.040 --> 0:13:10.239 most mammals do not have a cloeca. There are some exceptions, 0:13:10.280 --> 0:13:14.360 you know. You look at the monotremes, golden moles, marsupial moles, 0:13:14.760 --> 0:13:19.760 ten rex just a few examples, but mammals have mostly 0:13:19.880 --> 0:13:23.800 lost these general purpose openings over the course of their evolution, 0:13:24.160 --> 0:13:27.320 but in beaver's they seem to be present as a 0:13:27.320 --> 0:13:31.880 case of secondary evolution, perhaps as an adaptation I've read against. 0:13:32.160 --> 0:13:34.440 It may have to do with the watery environments they 0:13:34.440 --> 0:13:39.040 find themselves in, protecting themselves against infections that might occur 0:13:39.360 --> 0:13:42.199 due to the state of that water. But it's also 0:13:42.240 --> 0:13:44.800 something and this will become important, I believe in the 0:13:44.840 --> 0:13:47.000 next episode as well. It can make it difficult to 0:13:47.040 --> 0:13:50.559 sex a beaver, as males and females look pretty much 0:13:50.600 --> 0:13:53.600 the same unless the female happens to be pregnant or 0:13:53.679 --> 0:13:56.839 nursing at the time. That you're trying to sex them. 0:13:56.960 --> 0:13:58.959 And when I say you, I of course mean people 0:13:59.000 --> 0:14:02.200 who have authority and expertise to be out in the 0:14:02.200 --> 0:14:05.040 wild trying to sex the beaver. You know, leave it 0:14:05.080 --> 0:14:07.360 to the professional biologists. 0:14:06.960 --> 0:14:08.400 Leave it to beaver scientists. 0:14:08.640 --> 0:14:13.000 Yes, so these various features aid the beaver in its 0:14:13.040 --> 0:14:18.640 primary enterprise of ecosystem engineering. We all know that beavers 0:14:18.640 --> 0:14:21.520 build dams. You know, this is of course is true 0:14:21.520 --> 0:14:24.840 of the cartoons. But what does that really mean? Why 0:14:25.160 --> 0:14:28.400 why are beavers building dams? What are they accomplishing? So 0:14:28.440 --> 0:14:32.280 they actively alter their ecosystem via the blockage of rivers 0:14:32.320 --> 0:14:37.200 and streams with structures of like, you know, sticks, mud, 0:14:37.720 --> 0:14:41.000 chunks of trees, that sort of thing, all cobbled together 0:14:41.400 --> 0:14:43.880 to dam up the water, and this allows them to 0:14:43.880 --> 0:14:49.520 create new lakes, new ponds, whole floodplains. Meanwhile, the lodges 0:14:49.560 --> 0:14:52.320 they construct for themselves are also made out of this 0:14:52.400 --> 0:14:54.720 kind of stuff, branches and mud and so forth, and 0:14:54.760 --> 0:14:58.800 they can only be accessed from underwater entrances in their 0:14:58.840 --> 0:14:59.960 constructed ponds. 0:15:00.600 --> 0:15:02.560 Yeah, so this is something I don't know if I 0:15:02.640 --> 0:15:05.160 realized before. I think a lot of people assume that 0:15:06.040 --> 0:15:09.760 beavers live in their dams. But I think the better 0:15:09.760 --> 0:15:13.560 way to think about it is beavers construct dams in 0:15:13.680 --> 0:15:19.000 order to block waterways, which causes the area upstream of 0:15:19.040 --> 0:15:22.400 the dams to deepen and have a more lake like 0:15:22.560 --> 0:15:26.160 environment rather than a flowing river or stream. And then 0:15:26.360 --> 0:15:29.200 in that flooded area that is where they build the 0:15:29.280 --> 0:15:32.000 lodge they live in. So they sort of create a 0:15:32.120 --> 0:15:35.880 flooded area, which can it conserve multiple purposes, one to 0:15:36.120 --> 0:15:39.040 house the lodge, but then also they can sort of 0:15:39.600 --> 0:15:41.640 dig out from there. I think you're about to mention 0:15:41.720 --> 0:15:42.360 something about this. 0:15:42.920 --> 0:15:46.000 Yeah, they're a lot like humans. Human beings do this 0:15:46.080 --> 0:15:49.200 with their modern technology. They come to say a dry 0:15:49.280 --> 0:15:53.160 desert environment or a swamp environment, and they're like, you 0:15:53.200 --> 0:15:54.960 know what would go great here? What I would like 0:15:55.720 --> 0:15:57.880 for my purposes of living here. I'd love it to 0:15:57.920 --> 0:15:59.720 be just like a nice little park with some nice 0:16:00.480 --> 0:16:03.120 you know, and maybe a few trees. I'm going to 0:16:03.200 --> 0:16:06.600 change everything so that it fits my needs. So the 0:16:06.640 --> 0:16:10.240 primary purpose for the beaver dam is to create a 0:16:10.280 --> 0:16:14.280 protective body of water for that lodge, making it even 0:16:14.360 --> 0:16:17.440 more difficult for predators to get at them. And even 0:16:17.520 --> 0:16:20.360 if predators were to get to them, they have that 0:16:20.480 --> 0:16:23.560 underwater escape route in the event of an attack, that's 0:16:23.600 --> 0:16:25.840 the only the only way in and out. Now. It's 0:16:26.200 --> 0:16:29.560 worth noting, however, that especially in parts of Eurasia, beavers 0:16:29.560 --> 0:16:32.240 don't always have the same predator threat they once did, 0:16:32.680 --> 0:16:34.880 but they build anyway because no one told them not to. 0:16:35.400 --> 0:16:38.480 And also, more seriously, like, even though they are not 0:16:38.560 --> 0:16:41.000 predators now, I mean that's you know, any kind of 0:16:41.040 --> 0:16:45.440 evolutionary change would occur over a much vaster period of 0:16:45.480 --> 0:16:49.400 time than the removal of their predators amounts to. 0:16:50.120 --> 0:16:52.680 Right, So an environment full of say like gray wolves 0:16:52.680 --> 0:16:54.840 and bears may have shaped them. And even if there 0:16:54.880 --> 0:16:57.640 are many fewer of these predators than there once was, 0:16:57.760 --> 0:17:00.280 that they are still the animal made by that world. 0:17:00.720 --> 0:17:00.920 Right. 0:17:00.960 --> 0:17:04.040 For instance, they're still certainly nocturnal creatures. I mean they're 0:17:04.080 --> 0:17:06.840 also active, you know, dusk and dawn a little bit, 0:17:06.920 --> 0:17:11.119 but during the day proper they're inside, they're resting, and 0:17:11.240 --> 0:17:14.200 part of that is to avoid predators. Now, you mentioned earlier, 0:17:14.280 --> 0:17:16.760 Joe that even just looking at videos you can tell 0:17:16.760 --> 0:17:19.679 that they're more awkward on land than they are in 0:17:19.720 --> 0:17:24.240 the water. And that's of course another big important aspect 0:17:24.520 --> 0:17:27.920 of their damming of waterways, creating this sort of vast 0:17:27.960 --> 0:17:32.360 flood plain, like turning a stream going through a forest 0:17:33.720 --> 0:17:36.280 or something to this effect into kind of a flooded 0:17:36.320 --> 0:17:40.879 forest environment. This opens up speedy water routes back to 0:17:40.960 --> 0:17:43.440 their lodge. From perspective, feeding grounds. 0:17:43.680 --> 0:17:45.720 Yes, sort of the same way. You could imagine it, 0:17:45.800 --> 0:17:50.399 like humans creating roads like paved roads between say the 0:17:50.520 --> 0:17:53.040 farms that they work during the day and the houses 0:17:53.119 --> 0:17:55.919 they live in. But beavers would do this by instead 0:17:56.000 --> 0:17:58.800 creating flooded areas. Especially, they can sort of like dig 0:17:58.800 --> 0:18:01.760 out channels along the bottom that the water from these 0:18:01.760 --> 0:18:05.479 flooded areas can run into, allowing them to have a 0:18:05.520 --> 0:18:08.359 sort of canals like roads made of water where they 0:18:08.400 --> 0:18:11.040 can move quickly, where they can move submerged, which is 0:18:11.640 --> 0:18:14.280 safer and better for them than trying to move awkwardly 0:18:14.320 --> 0:18:14.960 over land. 0:18:15.640 --> 0:18:18.399 Yeah. Now, in doing this, of course, they alter the 0:18:18.440 --> 0:18:22.440 ecosystem local ecosystem in a major way, opens up opportunities 0:18:22.440 --> 0:18:26.000 for various other organisms as well, and also discuss some 0:18:26.080 --> 0:18:29.879 of the potential downsides at least for some organisms in 0:18:29.920 --> 0:18:32.120 a bit. But at any rate, this cements the beaver's 0:18:32.160 --> 0:18:37.760 place as a keystone species. Beaver's just just completely change 0:18:37.840 --> 0:18:41.879 the immediate environment, produces more open water, higher water tables. 0:18:42.520 --> 0:18:45.240 And yeah, it's this entire system they have going for 0:18:45.400 --> 0:18:48.000 them here is just so fascinating. You can if you 0:18:48.000 --> 0:18:51.840 look online, you can find some some side profiles, some 0:18:51.920 --> 0:18:55.720 cutaways of what the lodge looks like, and it's pretty ingenious. 0:18:56.040 --> 0:18:57.760 It also serves as a place for them to store 0:18:57.840 --> 0:19:01.479 food and even provides recue huge during frozen months. They 0:19:01.480 --> 0:19:05.320 don't hibernate properly, but they can hold up in there. 0:19:05.840 --> 0:19:07.720 One of the things I've read about is that they 0:19:08.800 --> 0:19:12.480 often can store lots of food, so they are vegetarians 0:19:12.480 --> 0:19:16.159 that eat actually, like you know, parts of trees, vegetation 0:19:16.320 --> 0:19:19.359 from all around them, which they can keep stored in 0:19:19.440 --> 0:19:24.639 the water underneath the pond created by their dams. And 0:19:24.680 --> 0:19:27.520 that's an interesting thing. They can raise the water level 0:19:27.680 --> 0:19:32.560 in order to help protect areas of food storage in 0:19:32.640 --> 0:19:35.359 the water for the winter, because by raising the water 0:19:35.480 --> 0:19:38.640 level they create more area underneath that won't freeze over 0:19:38.760 --> 0:19:39.840 when the weather gets cold. 0:19:40.240 --> 0:19:43.239 Yeah, and these these lodges and dams that they can 0:19:43.880 --> 0:19:48.440 they even though the beavers themselves tend only live about 0:19:48.440 --> 0:19:51.879 I think eight years max. A single lodge and dam 0:19:51.920 --> 0:19:55.280 can be maintained over generations, so the lodges may end 0:19:55.359 --> 0:19:58.480 up with like several stories to them, and the dams 0:19:58.480 --> 0:20:01.840 can get quite massive. There's an Alberta area dam that 0:20:02.000 --> 0:20:06.560 was built apparently in the nineteen seventies, initially wasn't discovered 0:20:06.640 --> 0:20:08.640 till around two thousand and seven because it's just out 0:20:08.640 --> 0:20:10.880 in the middle of nowhere. It's not like in downtown Alberta. 0:20:10.920 --> 0:20:14.119 It's like out in the boonies. And it's thought to 0:20:14.119 --> 0:20:17.439 be the world's largest beaver dam known beaver dam anyway, 0:20:17.480 --> 0:20:20.960 covering a good half mile. There's actually an Alice Obscure 0:20:21.040 --> 0:20:23.399 article about it. If anyone's interested, just look up world's 0:20:23.480 --> 0:20:26.440 largest beaver dam and you can see some like aerial photographs. 0:20:27.160 --> 0:20:28.960 You know, something interesting I was reading about was the 0:20:29.040 --> 0:20:34.479 role of beavers in maintaining ecosystem health by allowing for 0:20:34.520 --> 0:20:38.280 a greater diversity of different types of plant life to thrive. 0:20:38.359 --> 0:20:40.720 I think sort of in the same way that forest 0:20:40.840 --> 0:20:43.439 fires you might think of them as purely destructive. Of 0:20:43.440 --> 0:20:46.760 course they are destructive, but you know, forest fires occur 0:20:47.320 --> 0:20:51.080 naturally all the time, and when a forest burns, that 0:20:51.119 --> 0:20:55.040 creates sort of new opportunities for new types of plants 0:20:55.040 --> 0:20:57.600 and other life forms to thrive in a place that 0:20:57.720 --> 0:20:59.600 was once covered up by you know, a lot of 0:20:59.600 --> 0:21:03.240 tree camp. So in the areas around beaver dams and lodges, 0:21:03.320 --> 0:21:05.640 they will clear out lots of the trees. They literally 0:21:05.760 --> 0:21:07.840 chew them down and they'll fall, and you know, the 0:21:07.840 --> 0:21:10.600 beavers will do what they will with them. But this 0:21:10.720 --> 0:21:14.040 creates all kinds of opportunities for other plants and other 0:21:14.320 --> 0:21:17.359 life forms that wouldn't normally thrive in the forest to 0:21:18.320 --> 0:21:18.919 have a shot. 0:21:19.640 --> 0:21:24.360 Yeah. Yeah, the paper that I came across was talking 0:21:24.359 --> 0:21:26.520 about sort of like the pros and cons. I have 0:21:26.560 --> 0:21:28.920 another one I'll get into about some of the potential benefits, 0:21:28.920 --> 0:21:32.840 but just to give you a full idea of sort 0:21:32.840 --> 0:21:36.560 of the rodent altered landscape we're talking about here, I 0:21:36.600 --> 0:21:39.720 was looking at a twenty fifteen paper published in IOP 0:21:39.920 --> 0:21:43.760 conference series or presented in the IOP conference series Earth 0:21:43.760 --> 0:21:48.360 and Environmental Science. This one is this was by Raskova 0:21:48.480 --> 0:21:51.359 to Mina at All, and they talk about some of 0:21:51.400 --> 0:21:55.000 the positive and negative consequences, at least initially stressing some 0:21:55.040 --> 0:21:58.639 of the negatives maybe that are not at least instantly 0:21:58.680 --> 0:22:02.280 discussed as much. But you get soil overwetting obviously, because 0:22:02.440 --> 0:22:06.000 you're getting flooding occurrently that occurs, you also can have 0:22:06.119 --> 0:22:10.960 water stagnation that results in lack of oxygen, high carbon concentration, 0:22:11.320 --> 0:22:14.720 and the death of many aquatic organisms. And then the 0:22:14.760 --> 0:22:18.359 flooding can also cause vegetation death. But at the same time, 0:22:18.560 --> 0:22:20.800 the authors are stressed that it can result in a 0:22:20.920 --> 0:22:25.679 rise in the biodiversity of water organisms. So you know, 0:22:26.960 --> 0:22:29.880 they're changing everything. They're changing the balance of the local ecosystem, 0:22:30.680 --> 0:22:33.399 and it's creating a lot of opportunities for new things, 0:22:33.480 --> 0:22:36.919 but it is also cutting things short for things that 0:22:36.960 --> 0:22:41.359 we're living there already. Now, a really interesting study that 0:22:41.400 --> 0:22:44.880 I came across this was a twenty twenty two Stanford 0:22:44.920 --> 0:22:48.760 study by Dewey at All published in Nature Communications, And 0:22:48.880 --> 0:22:52.160 in this paper they point out that beaver habitat ranges 0:22:52.200 --> 0:22:54.719 in the US are going to continue to widen with 0:22:54.800 --> 0:22:58.440 warming temperatures driven by climate change, but the benefits of 0:22:58.520 --> 0:23:04.080 their dam building will actually quote overshadow climate extremes quote. 0:23:04.119 --> 0:23:06.679 So this is not to say beaver dams will cancel 0:23:06.760 --> 0:23:09.920 out climate change or anything like that, but in some 0:23:10.000 --> 0:23:13.960 respects it kind of lessens the blow specifically as far 0:23:14.040 --> 0:23:20.160 as water quality in mountain watersheds are concerned. Beaver dams 0:23:20.400 --> 0:23:25.520 can raise water levels upstream and divert water into soil 0:23:25.640 --> 0:23:28.840 and surrounding waterways, and this ends up sort of, This 0:23:28.960 --> 0:23:31.920 ends up like creating a robust filter system, a filtration 0:23:32.080 --> 0:23:36.920 system for excess nutrients and contaminants for the water before 0:23:36.960 --> 0:23:41.439 it passes on downstream. So today beaver's in North American 0:23:41.480 --> 0:23:45.760 Eurasia are both doing great. They have bounced back from 0:23:45.800 --> 0:23:48.800 near extinction due to hunting, and we may touch on 0:23:48.880 --> 0:23:52.720 some of that a little bit more in the next episode, 0:23:52.760 --> 0:23:55.280 but because there are a few different reasons that have 0:23:55.359 --> 0:23:59.480 driven beaver hunting over the years. But to go back 0:23:59.520 --> 0:24:03.720 to speaking of their construction of dams and their changing 0:24:03.760 --> 0:24:08.120 of the environment, there's another great illustration I came across 0:24:08.320 --> 0:24:12.159 by Nicholas Defer, who lives sixteen forty six through seventeen twenty, 0:24:12.720 --> 0:24:15.680 and this is just a small scene from a larger map. 0:24:15.720 --> 0:24:20.240 He was a French cartographer, so this illustration is just 0:24:20.800 --> 0:24:23.000 filling in some of the blank spaces, like we've discussed 0:24:23.000 --> 0:24:26.200 before on some of these older maps. But this illustration 0:24:26.320 --> 0:24:31.240 shows beavers at work. They are downing trees and they 0:24:31.280 --> 0:24:35.640 are dragging off the wood to build things. The beavers 0:24:35.680 --> 0:24:39.800 themselves look largely accurate. There may be a little more 0:24:39.800 --> 0:24:44.760 bear like, but the basic morphology is there. The main 0:24:44.880 --> 0:24:48.359 problems here are that, first of all, there's like, you know, 0:24:48.400 --> 0:24:51.680 one hundred beavers in this one image, like they're working 0:24:51.720 --> 0:24:55.640 as an army. And then also like clearly there wasn't 0:24:55.640 --> 0:24:57.960 a lot of detail on how they carry the wood, 0:24:58.240 --> 0:25:01.920 because the central beav that you see is standing up 0:25:02.160 --> 0:25:06.040 in a bipedal posture with an armload of wood thrown 0:25:06.080 --> 0:25:08.040 over his shoulder like a human being. 0:25:08.320 --> 0:25:11.760 Yeah yeah, like a Paul Bunyon carrying an axe. 0:25:12.400 --> 0:25:13.640 Yeah. 0:25:13.680 --> 0:25:16.440 But I like the spirit of industry that they captured here, 0:25:16.840 --> 0:25:20.760 despite some of the ridiculous details, and again a huge 0:25:20.840 --> 0:25:24.480 improvement over some illustrations from previous centuries. 0:25:24.800 --> 0:25:26.920 I wonder is this one of the maps we looked 0:25:26.960 --> 0:25:29.520 at in our Horror Vakae episodes where we were talking 0:25:29.520 --> 0:25:32.080 about maps with excessive illustrations. 0:25:32.400 --> 0:25:35.439 I don't believe it is. I looked at a bigger 0:25:35.520 --> 0:25:37.280 version of the map and I almost included it in 0:25:37.280 --> 0:25:39.679 our notes, and I don't think I had seen it before. 0:25:40.520 --> 0:25:43.800 It was a map that it's known as the Beaver map. 0:25:43.840 --> 0:25:47.240 And has to do with the locations of beavers, because 0:25:47.240 --> 0:25:49.840 it has to do with the hunting of beavers, which 0:25:49.880 --> 0:25:52.800 again was quite a big industry for a while there, 0:25:53.080 --> 0:25:56.040 so big that it just about wiped them out. So 0:25:56.160 --> 0:25:59.600 the large semi aquatic rodents have come to flood the 0:25:59.640 --> 0:26:04.199 world and to remake it according to their designs. But 0:26:04.520 --> 0:26:09.120 the weirdness and the complexity doesn't stop there. Joe tell 0:26:09.160 --> 0:26:13.679 us a little bit about beaver society and about beaver 0:26:13.840 --> 0:26:14.520 tool use. 0:26:15.280 --> 0:26:18.280 Yeah, Rob, I think you found one of these papers first, 0:26:18.320 --> 0:26:20.440 and that's what started this whole thing. But I got 0:26:20.480 --> 0:26:23.880 lost on a going down a rabbit hole or maybe 0:26:23.920 --> 0:26:29.280 a beaver canal, trying to search out examples of possible 0:26:29.480 --> 0:26:34.080 tool use documented in beavers, and in fact, there are 0:26:34.160 --> 0:26:38.119 a few very interesting different observations corresponding to each of 0:26:38.160 --> 0:26:42.520 the extant species. Beavers clearly are an interesting type of 0:26:42.560 --> 0:26:45.600 animal to look at for signs of tool using intelligence, 0:26:45.640 --> 0:26:49.560 since they are masters of manipulating their environment through the 0:26:49.640 --> 0:26:53.360 dams and the lodges they build. Though I think it's 0:26:53.359 --> 0:26:56.879 interesting that nest building is often not typically thought of 0:26:57.080 --> 0:26:59.520 or not sort of front of mind as an example 0:26:59.560 --> 0:27:02.320 of tool use, and there are different examples the different 0:27:02.680 --> 0:27:06.879 zoologists or animal behavior experts will use to try to 0:27:07.000 --> 0:27:10.480 define tool use. So in the papers I was looking at, 0:27:10.480 --> 0:27:14.800 a few different standards were cited. One is a definition 0:27:14.840 --> 0:27:18.399 of tool use by a researcher named Alcock, who says 0:27:18.480 --> 0:27:22.119 it is quote the manipulation of an inanimate object that 0:27:22.240 --> 0:27:26.439 improves the organism's efficiency in altering the position or form 0:27:26.640 --> 0:27:30.600 of some other object. So, you know, using an inanimate 0:27:30.680 --> 0:27:35.000 object from the environment to better alter the former position 0:27:35.280 --> 0:27:39.080 of something else. Another definition I've found cited this is 0:27:39.119 --> 0:27:43.760 from Beck in nineteen eighty quote the external employment of 0:27:43.800 --> 0:27:48.960 an unattached environmental object to alter more efficiently the form, position, 0:27:49.280 --> 0:27:53.480 or condition of another object, another organism, or the user 0:27:53.520 --> 0:27:56.879 itself when the user holds or carries the tool during 0:27:57.320 --> 0:28:00.199 or just prior to use, and is responsible for the 0:28:00.240 --> 0:28:04.680 proper and effective orientation of the tool. Now, I appreciate 0:28:04.720 --> 0:28:06.960 all of the conditions on that, because I think it 0:28:07.040 --> 0:28:09.960 is important for people to be specific about what they're 0:28:10.000 --> 0:28:12.360 talking about when they look for examples of tool use. 0:28:12.440 --> 0:28:16.399 But I also wonder, once you're specifying that many conditions, 0:28:17.160 --> 0:28:20.560 is the category of tool use becoming more like a 0:28:20.600 --> 0:28:25.520 function of the definition you lay out than a fundamentally 0:28:25.560 --> 0:28:29.040 different type of activity itself than some other activity that 0:28:29.320 --> 0:28:31.000 wouldn't quite fit this definition. 0:28:31.440 --> 0:28:33.320 Yeah, I mean, and sometimes we can almost get too 0:28:33.400 --> 0:28:35.600 hung up, I think, on the on the idea of 0:28:35.680 --> 0:28:37.560 tool use and the definition of tool use, because we'll 0:28:37.560 --> 0:28:40.880 look at the most complicated burden, nest or bower that 0:28:40.960 --> 0:28:43.160 you can imagine and will be like, well, it's intricate, 0:28:43.240 --> 0:28:47.040 it's amazing, it's beautiful. But have you seen this monkey 0:28:47.240 --> 0:28:51.240 stabbing a smaller monkey with a stick? You know, it's 0:28:51.680 --> 0:28:55.320 you know, it can almost you can almost set it 0:28:55.400 --> 0:28:57.800 up as this this thing that is the thing that 0:28:57.880 --> 0:29:00.000 we do. You know, that is a very there's something 0:29:00.080 --> 0:29:02.760 very human about tool use, and you know, obviously a huge, 0:29:03.080 --> 0:29:08.240 huge aspect of human life and human development. But yeah, 0:29:08.240 --> 0:29:11.880 it seems like at times a lot of extra mental 0:29:11.880 --> 0:29:16.480 gymnastics has to be utilized in order to even discuss it. 0:29:16.640 --> 0:29:18.600 So I'm not going to get super hung up on 0:29:19.120 --> 0:29:21.840 definitions of tool use or what really counts as tool 0:29:21.920 --> 0:29:24.360 use today. We've talked about some of those debates in 0:29:24.760 --> 0:29:28.000 plenty of episodes in the past. Instead, I'm just going 0:29:28.040 --> 0:29:31.560 to like talk about some studies describing specific behaviors and 0:29:31.600 --> 0:29:33.320 you can make up your own mind about whether it 0:29:33.320 --> 0:29:35.600 seems like tool use to you. So the first thing 0:29:35.640 --> 0:29:39.120 I want to talk about is an older observation. It's 0:29:39.160 --> 0:29:41.560 older than either of the two papers that I'm going 0:29:41.600 --> 0:29:43.840 to discuss here, but it's cited in the first of them, 0:29:43.840 --> 0:29:46.320 and I'll get to that paper itself in the second. 0:29:47.000 --> 0:29:51.600 But the observation is that a researcher named Georgio Pilleri 0:29:52.200 --> 0:29:56.520 observes something interesting while studying two captive beavers at the 0:29:56.640 --> 0:30:02.200 Burn Brain Anatomy Institute in nineteen eighty. So, the beavers 0:30:02.200 --> 0:30:05.040 were living in a concrete pool that was supplied with 0:30:05.120 --> 0:30:09.240 a constant flow of fresh water, and overflow of this 0:30:09.320 --> 0:30:13.400 pool was routed away through a series of three drain holes, 0:30:13.520 --> 0:30:17.520 each zero point eight centimeters in diameters little holes, And 0:30:17.600 --> 0:30:21.080 the beavers had been given a supply of sticks and 0:30:21.120 --> 0:30:24.760 twigs to do what they wanted with, and for some reason, 0:30:25.080 --> 0:30:29.440 what they did is they selected and cut three sticks 0:30:29.520 --> 0:30:33.800 from their supply to the exact dimensions needed to plug 0:30:33.920 --> 0:30:37.200 the tiny drain holes that where water drained away from 0:30:37.240 --> 0:30:40.840 their pool, and this completely stopped the flow of water 0:30:41.000 --> 0:30:44.760 away from the pool. Now, what's going on here? At first, 0:30:44.800 --> 0:30:46.480 It was kind of hard for me to believe this 0:30:46.560 --> 0:30:50.280 would be fully intentional behavior, as in, like the beavers 0:30:50.360 --> 0:30:53.720 understood that they were plugging the drains to stop the 0:30:53.760 --> 0:30:57.160 flow of water from their enclosure. But then I thought, 0:30:57.200 --> 0:30:59.840 you know, I guess I wouldn't be surprised if beaver 0:31:00.280 --> 0:31:03.920 have like a sense for detecting gaps in dams and 0:31:03.960 --> 0:31:07.520 plugging them, Like maybe they're good at sensing. My first 0:31:07.520 --> 0:31:10.400 instinct was maybe they sense like the delta pee, you know, 0:31:10.480 --> 0:31:13.080 the difference in pressure, like when water from a large 0:31:13.080 --> 0:31:15.320 pool is flowing out of a small pipe or hole, 0:31:15.360 --> 0:31:17.480 and you could feel that pressure that would like get 0:31:17.520 --> 0:31:19.480 your hands stuck to the hole if you held it there, 0:31:19.840 --> 0:31:22.720 or which in larger scenarios can be of a great 0:31:22.800 --> 0:31:25.120 danger to divers. You know, you don't want to go 0:31:25.200 --> 0:31:27.640 near like the intake hole and a dam if you're 0:31:27.680 --> 0:31:31.959 diving near it. I thought, maybe they sensed the delta pee, 0:31:32.040 --> 0:31:35.640 and so they sense that and they naturally want to 0:31:35.680 --> 0:31:39.440 plug it up. But I didn't know. However, I then 0:31:39.480 --> 0:31:42.280 sort of came across an answer. So I was watching 0:31:42.320 --> 0:31:46.680 a segment on North American beavers from BBC Earth, narrated 0:31:46.680 --> 0:31:51.640 by David Attenborough, and this documentary segment captured a scene 0:31:51.760 --> 0:31:56.520 of beavers finding a leak in their dam and then 0:31:56.600 --> 0:31:59.840 getting right to work retrieving wood, vegetation and clumps of 0:32:00.120 --> 0:32:02.600 ediment down from the bottom of the pond to plug 0:32:02.760 --> 0:32:04.960 up the leak in the dam where water was running 0:32:04.960 --> 0:32:09.080 over the top, and Attenborough in this documentary segment narrates 0:32:09.080 --> 0:32:13.360 that beavers are thought to detect these leaks by hearing 0:32:13.440 --> 0:32:17.000 the sound of trickling water, and when they do, they 0:32:17.040 --> 0:32:21.440 begin repair work almost immediately. So it seems to be fastidious, 0:32:21.480 --> 0:32:26.040 almost compulsive, this compulsive desire to fix the holes when 0:32:26.080 --> 0:32:28.760 they hear the water trickling, and this would make the 0:32:29.000 --> 0:32:32.760 drain plugging behavior in the concrete enclosure in the eighties 0:32:33.280 --> 0:32:36.240 make a lot more sense. So I decided to look 0:32:36.280 --> 0:32:39.440 into this further to see if this was indeed true 0:32:39.760 --> 0:32:43.200 to some degree. It seems it is, and so I 0:32:43.240 --> 0:32:45.840 didn't have time. This was soon before we started recording. 0:32:45.880 --> 0:32:48.240 I didn't have time to find the primary reference on this, 0:32:48.720 --> 0:32:52.080 but I did find a good twenty fifteen Gizmoto blog 0:32:52.120 --> 0:32:57.200 post by Esther inglis Arkele writing up summarizing the research 0:32:57.320 --> 0:33:01.480 of a Swedish zoologist named Lars Wilson, who studied beavers 0:33:01.480 --> 0:33:04.480 back in the nineteen sixties, and according to the summary, 0:33:04.720 --> 0:33:09.480 Lars Wilson found that dam building was instinctual rather than learned, 0:33:09.600 --> 0:33:12.720 and the way Wilson identified with this was that if 0:33:12.720 --> 0:33:15.680 you took young beavers and you separated them from their 0:33:15.760 --> 0:33:19.600 parents at birth, they would still build dams basically the 0:33:19.640 --> 0:33:22.320 same way, using the same techniques as their parents, even 0:33:22.360 --> 0:33:24.800 though they were clearly not having the opportunity to be 0:33:24.880 --> 0:33:27.240 taught to do that. So it seems based on that 0:33:27.280 --> 0:33:30.080 at least this is probably a routine behavior. It's based 0:33:30.120 --> 0:33:32.960 on beaver DNA. They don't have to be taught. But 0:33:33.560 --> 0:33:38.200 Wilson also found that beavers didn't always build dams. In 0:33:38.280 --> 0:33:42.480 environments with still water or only very gently moving water, 0:33:43.000 --> 0:33:45.320 dam building was not a priority. The beavers would just 0:33:45.320 --> 0:33:47.080 maybe they like dig a hole in the mud and 0:33:47.160 --> 0:33:49.760 just chill there, you know, they just wouldn't build. And 0:33:49.840 --> 0:33:54.600 so by manipulating different variables, Wilson identified the sound of 0:33:54.680 --> 0:33:58.640 trickling water as the primary trigger for dam building, even 0:33:58.680 --> 0:34:00.480 to the point of a discovery that I this was 0:34:00.520 --> 0:34:02.840 the part I found most fascinating. If you put a 0:34:03.000 --> 0:34:07.479 speaker in the beaver's enclosure and you played the sound 0:34:07.560 --> 0:34:11.239 of trickling water through it, the beavers would go to 0:34:11.280 --> 0:34:13.719 the speaker and start building on top of it. They 0:34:13.719 --> 0:34:17.880 would start piling up sticks and mud and branches over 0:34:18.040 --> 0:34:21.080 the speaker playing the water sounds. They were trying to 0:34:21.200 --> 0:34:24.040 plug the speaker to make it stop leaking. 0:34:24.760 --> 0:34:25.640 Oh my goodness. 0:34:26.040 --> 0:34:29.359 Wilson also found that if outflow pipes, so you had 0:34:29.400 --> 0:34:33.200 a place where there was actually water leading away from 0:34:33.360 --> 0:34:36.680 the from the pool, but you carefully designed the pipe 0:34:36.719 --> 0:34:39.120 so that they made no noise, the beavers would not 0:34:39.160 --> 0:34:41.600 be able to find and cover them. So this might 0:34:41.680 --> 0:34:44.200 lead you to think, okay, so like the louder the 0:34:44.320 --> 0:34:47.040 rushing of the water, the more beavers want to make 0:34:47.080 --> 0:34:49.239 a damn there. But it also seems like it's not 0:34:49.320 --> 0:34:53.040 quite that simple, because I was reading a news article 0:34:53.080 --> 0:34:55.840 from the Harvard Graduate School of the Arts and Sciences 0:34:56.200 --> 0:35:00.760 called Damned if They Do by Paul Massari. This article 0:35:00.800 --> 0:35:04.640 profiles the research of an environmental engineer named Jordan Kennedy 0:35:05.320 --> 0:35:08.880 who has done research on beavers and their dam building 0:35:08.880 --> 0:35:13.640 practices and the environmental effects thereof. And Kennedy says that 0:35:13.840 --> 0:35:17.640 it can't just be about like the magnitude of sound 0:35:17.680 --> 0:35:20.120 of moving water, or beavers would be trying to build 0:35:20.200 --> 0:35:23.800 dams across Niagara Falls, you know, just like loud, violent, 0:35:23.880 --> 0:35:27.560 rushing waters where building would be totally impractical. So instead, 0:35:27.600 --> 0:35:30.000 there's got to be a kind of Goldilocks zone for 0:35:30.120 --> 0:35:34.600 damn construction, something that the beavers naturally detect that allows 0:35:34.640 --> 0:35:37.120 them to know, Okay, this is about the right amount 0:35:37.200 --> 0:35:39.160 of flow to try to dam up. 0:35:39.680 --> 0:35:42.640 Yeah, yeah, damming up Niagara Falls. Like obviously that would 0:35:42.640 --> 0:35:45.960 be great, Like that's kind of like the beaver fan fiction, 0:35:46.080 --> 0:35:49.680 that's the pipe drain, But is it practical. No, you 0:35:49.680 --> 0:35:52.480 need to have that just the right environment that can 0:35:52.520 --> 0:35:56.760 then be manipulated to make the ideal environment for the beaver. 0:35:57.400 --> 0:36:00.560 Right, So the author of this article right now, it's quote, 0:36:00.600 --> 0:36:02.759 the water in a beaver's habitat needs to be a 0:36:02.760 --> 0:36:06.160 certain depth, for instance, to keep a food cash from 0:36:06.200 --> 0:36:09.160 freezing to the bottom in winter and to enable them 0:36:09.200 --> 0:36:12.640 to evade predators. The plants that beavers prefer to eat 0:36:12.760 --> 0:36:16.600 flourish best when water flows at a certain velocity. So 0:36:17.040 --> 0:36:20.400 you're looking for this Goldilocks zone, an area of a 0:36:20.560 --> 0:36:23.680 certain amount of water flow, maybe a certain narrowness of 0:36:23.719 --> 0:36:26.760 the channel or certain depth of the channel and that's 0:36:26.840 --> 0:36:28.960 the place where you want to dam it up. And 0:36:29.320 --> 0:36:33.000 beavers apparently they locate that A big part of the 0:36:33.880 --> 0:36:37.520 sense data informing them of that area appears to be sound. 0:36:37.640 --> 0:36:40.239 Maybe the overwhelming part of it is sound, but there 0:36:40.239 --> 0:36:43.799 may be other cues as well, And so I don't know. 0:36:43.840 --> 0:36:45.759 I thought this was so interesting, And I'm just trying 0:36:45.760 --> 0:36:48.680 to imagine what it's like to be a beaver to 0:36:48.840 --> 0:36:54.720 have this powerful instinctual drive to plug leaks. So imagine 0:36:54.760 --> 0:36:58.200 the same kind of base level instinctual drive that humans 0:36:58.280 --> 0:37:02.319 might have for sex, or for food, or to care 0:37:02.400 --> 0:37:05.920 for children, all the like the most powerful drives in 0:37:05.960 --> 0:37:09.319 our brains. But there's a drive like that to hunt 0:37:09.400 --> 0:37:12.360 down the source of anything that sounds like trickling water 0:37:12.520 --> 0:37:16.800 and to just plug it with junk. You know, I 0:37:16.840 --> 0:37:19.080 don't know, that's like that's another that's another type of 0:37:19.440 --> 0:37:22.120 mind experience or relationship to the environment. 0:37:22.840 --> 0:37:26.560 Wow wow, yeah, Like what would yeah, how would like 0:37:26.920 --> 0:37:29.319 we can't help but extravolate that into like a a 0:37:29.440 --> 0:37:32.360 human like intellect and human like culture, Like what would 0:37:32.440 --> 0:37:36.760 advance beaver civilization be? Like? Would they actually go after 0:37:36.880 --> 0:37:41.640 like complete inundation, like a complete flooding situation, the destruction 0:37:41.920 --> 0:37:45.799 of of of all naturally occurring waterfalls, or would they 0:37:45.840 --> 0:37:48.000 just kind of dream about it? Or what would their 0:37:48.000 --> 0:37:51.280 TV shows be? Would it just be like countless channels 0:37:51.320 --> 0:37:54.080 of leak plugging and so forth. 0:37:54.680 --> 0:37:56.960 The speaver thought she had it all, but then she 0:37:57.160 --> 0:38:01.400 heard the trickle and couldn't find it searching, Like all 0:38:01.680 --> 0:38:04.200 dramas begin with the conflict of hearing a trickle. 0:38:05.040 --> 0:38:06.440 That's the called adventure. 0:38:06.560 --> 0:38:18.600 Yeah, but anyway, all that stuff I just read about 0:38:18.600 --> 0:38:21.919 got kicked off because I was reading that anecdote about 0:38:21.920 --> 0:38:25.919 the findings of Giorgio Pillari in nineteen eighty three, which 0:38:26.040 --> 0:38:29.360 was cited in a paper by D. M. Barnes called 0:38:29.520 --> 0:38:33.600 Possible tool use by beaver's Castor canadensis in a Northern 0:38:33.640 --> 0:38:37.400 Ontario watershed published in The Canadian Field Naturalist in two 0:38:37.440 --> 0:38:39.799 thousand and five. So this is one of the main 0:38:39.800 --> 0:38:43.160 two papers I was looking at about possible cases of 0:38:43.200 --> 0:38:46.440 tool use in beaver's Barnes says that this report is 0:38:46.440 --> 0:38:50.120 based on evidence relating to the North American beaver that's 0:38:50.200 --> 0:38:53.600 Castor candidensis at a remote damn site in the Chapleaux 0:38:53.680 --> 0:38:57.279 Crown Game Preserve in northern Ontario. The author says, at 0:38:57.280 --> 0:39:01.440 this location they found a clump of willow stems, so 0:39:01.560 --> 0:39:05.560 like little small tree trunks that had been cut by beavers. 0:39:05.840 --> 0:39:09.080 But the fascinating thing was they were cut at the 0:39:09.200 --> 0:39:15.480 extraordinary height of approximately one meter off the ground. Beavers 0:39:15.480 --> 0:39:18.480 are not that tall Normally, these beavers cut at an 0:39:18.480 --> 0:39:23.000 average height of about thirty centimeters, so the beavers were 0:39:23.040 --> 0:39:26.880 chomping off these willow trees at three times the normal 0:39:26.920 --> 0:39:30.960 height they could reach with their teeth. Barnes writes, quote, 0:39:31.000 --> 0:39:34.360 I made a careful examination of the area and found 0:39:34.360 --> 0:39:37.000 that there was no apparent way the beavers could have 0:39:37.160 --> 0:39:40.000 cut the stems at such a height. When I studied 0:39:40.000 --> 0:39:42.360 the willow clump more closely, I noted that there was 0:39:42.400 --> 0:39:46.560 a freshly cut willow stem approximately twelve centimeters in diameter, 0:39:47.160 --> 0:39:51.080 leaning against the main stem of the willow clump. Its 0:39:51.080 --> 0:39:55.280 approximate angle was forty five degrees. In addition, I observed 0:39:55.360 --> 0:39:59.360 cutting at both ends of the leaning willow segment, and 0:39:59.400 --> 0:40:01.480 then there was a There was a photo accompanying this 0:40:01.520 --> 0:40:04.799 in the article. Now, at first the author thought that, okay, 0:40:04.880 --> 0:40:07.440 so this is a log propped up forty five degrees 0:40:07.520 --> 0:40:11.239 against the tree that is cut off very tall. The 0:40:11.280 --> 0:40:16.560 author thought, maybe this log there had simply fallen that way. 0:40:16.600 --> 0:40:18.440 I don't know, it's something that the beaver cut and 0:40:18.480 --> 0:40:21.560 then it fell. But that seemed impossible on further examination, 0:40:22.000 --> 0:40:25.160 because the log was clearly from a different tree than 0:40:25.200 --> 0:40:27.600 the stem it was leaning against, like there was different 0:40:27.640 --> 0:40:32.480 bark texture and color and so forth, and its position 0:40:32.640 --> 0:40:35.400 just did not seem plausible if it had fallen from above. 0:40:36.120 --> 0:40:39.880 Another possibility the author considered was that these willow trunks 0:40:39.880 --> 0:40:43.080 had been foraged while there was heavy snow on the 0:40:43.080 --> 0:40:45.479 ground in the winter. So maybe the beavers were able 0:40:45.520 --> 0:40:48.680 to reach a meter up the trunks of these trees 0:40:49.600 --> 0:40:52.200 by crawling around on top of the snow. 0:40:52.840 --> 0:40:54.399 Okay, but the. 0:40:54.360 --> 0:40:57.520 Author things that's really unlikely given the position of the 0:40:57.520 --> 0:41:01.359 willow clump relative to the beaver dam and lodge and 0:41:01.440 --> 0:41:04.680 its entrance and exit. It seems it would have required 0:41:04.719 --> 0:41:09.080 a major overland journey by the beavers on the top 0:41:09.120 --> 0:41:12.160 of the snow in the winter at a time where 0:41:12.200 --> 0:41:16.040 this just would not fit with their normal behavior. Instead, 0:41:16.040 --> 0:41:19.040 the author suggests that maybe what happened here is the 0:41:19.080 --> 0:41:23.000 beaver used a prop. The beaver used a piece of 0:41:23.040 --> 0:41:25.520 a log that it had cut off at both ends 0:41:25.960 --> 0:41:28.400 and propped it up against the base of the trees, 0:41:28.600 --> 0:41:31.319 and then climbed up that and was able to chew 0:41:31.400 --> 0:41:35.080 off the willow stems at an upper level rather than 0:41:35.120 --> 0:41:37.920 a lower level. Now, why would this even be beneficial? 0:41:38.480 --> 0:41:42.760 The author says this would be probably to reduce foraging time. 0:41:43.400 --> 0:41:46.320 So the longer you forage, number one, the more thermal 0:41:46.360 --> 0:41:50.440 stress you're exposed to not being the right temperature, but 0:41:50.480 --> 0:41:54.360 more importantly, the longer you are exposed to predation. Apparently 0:41:54.360 --> 0:41:56.800 beavers do not like to spend a lot of time 0:41:57.080 --> 0:42:00.399 out on the ground out of the water. They were 0:42:00.400 --> 0:42:03.239 trying to hustle as fast as they can whenever they're 0:42:03.239 --> 0:42:06.759 out there cutting, and in this case, apparently using a 0:42:06.840 --> 0:42:11.040 cut stem to climb up the willow trunks to access 0:42:11.080 --> 0:42:13.960 a higher up part of the tree to chew through 0:42:14.280 --> 0:42:16.800 would have meant that they had to spend less time 0:42:16.880 --> 0:42:18.280 chewing and less time cutting. 0:42:18.920 --> 0:42:20.920 All right, So they go like a little bit higher. 0:42:21.239 --> 0:42:23.320 They just it's going to be less it's going to 0:42:23.360 --> 0:42:25.879 be a narrower bit of wood to chew through. 0:42:26.280 --> 0:42:29.720 That's what I assumed. It didn't specify exactly why cutting 0:42:29.760 --> 0:42:32.759 higher up was reduced foraging time. But that was my interpretation. 0:42:32.880 --> 0:42:36.560 I could be wrong, and that's why they potentially could 0:42:36.640 --> 0:42:41.439 be using essentially a beaver ladder a beaver bit of scaffolding. 0:42:41.160 --> 0:42:43.759 Right, but we don't know. This is just one observation. 0:42:44.040 --> 0:42:46.719 And also they didn't see them doing it. They just 0:42:46.800 --> 0:42:49.760 found this strange piece of scaffolding there later. 0:42:50.280 --> 0:42:52.799 Yeah. More mysteries related to and I mean, I guess 0:42:52.800 --> 0:42:54.440 this is kind of cutting into some of the mysteries 0:42:54.560 --> 0:42:58.880 involved in these wildly inaccurate depictions of beavers, is that 0:42:58.960 --> 0:43:03.600 these are creatures that live of often in very rural situations, 0:43:03.960 --> 0:43:08.040 far from human activity. They're probably doing it at night, 0:43:08.400 --> 0:43:11.799 and they're spending as little time necessary doing it out 0:43:11.840 --> 0:43:13.799 where other eyes could see them. 0:43:14.280 --> 0:43:18.479 Right, Okay. Second paper I came across alleging possible tool 0:43:18.560 --> 0:43:22.000 use behaviors by beavers. This is called tool use in 0:43:22.040 --> 0:43:26.279 a display behavior by Eurasian beavers or castor fiber in 0:43:26.360 --> 0:43:29.279 the journal Animal Cognition by Thompson at All in two 0:43:29.360 --> 0:43:32.400 thousand and seven. So here the authors write that documentation 0:43:32.520 --> 0:43:36.800 of tool use is relatively rare in rodents, and prior 0:43:36.840 --> 0:43:40.120 to this paper there were no documented cases. They knew 0:43:40.120 --> 0:43:43.160 of of tools being used by rodents in what are 0:43:43.200 --> 0:43:47.440 called agonistic displays. Now, agonistic is a word used in 0:43:47.480 --> 0:43:51.440 the study of animal behavior to describe conflict or fighting. 0:43:51.680 --> 0:43:56.120 So an agonistic behavior is not necessarily fighting itself, but 0:43:56.400 --> 0:44:00.600 also could include social behaviors related to fighting. So these 0:44:00.640 --> 0:44:05.040 would include threat displays, trying to look big or otherwise 0:44:05.080 --> 0:44:09.480 intimidate another animal, displays of aggression, as well as things 0:44:09.600 --> 0:44:13.080 like submission or retreat behavior. The authors of this paper 0:44:13.160 --> 0:44:16.200 say that in their field observations of the Eurasian beaver, 0:44:16.600 --> 0:44:20.319 they witnessed a behavior that they call stick display, which 0:44:20.360 --> 0:44:25.000 they interpreted as an agonistic display behavior. And what this 0:44:25.120 --> 0:44:28.080 consisted of is beaver would go pick up an object, 0:44:28.680 --> 0:44:31.719 usually a stick, whenever a stick was available, and then 0:44:31.760 --> 0:44:34.759 it would rise up on its hind legs and then 0:44:35.160 --> 0:44:38.840 move the upper body rapidly up and down while holding 0:44:38.880 --> 0:44:42.200 the stick or other object in its mouth and front paws. 0:44:42.840 --> 0:44:45.120 And Rabi attached a picture for you to look at. 0:44:45.120 --> 0:44:47.239 They had a photo of this. In this photo of 0:44:47.239 --> 0:44:50.239 the beaver is in the shallow part of a waterway. 0:44:50.600 --> 0:44:53.719 It's standing up on its back legs. It's kind of 0:44:54.239 --> 0:44:57.040 I don't know how to it's kind of like roaring posture. 0:44:57.120 --> 0:44:58.879 But it's got a big old stick in its mouth, 0:44:58.920 --> 0:45:01.560 and it's gripping the dick with its two four paws, 0:45:01.960 --> 0:45:04.759 and the water is splashing all around. It's the stick, 0:45:04.800 --> 0:45:06.520 I guess, rapidly dips in and out. 0:45:06.800 --> 0:45:10.480 It's impressive, and it's it's frankly a little intimidating. This 0:45:10.480 --> 0:45:13.880 this beaver saying, behold, look at the at the feats 0:45:13.920 --> 0:45:15.360 of strength I am capable of. 0:45:15.760 --> 0:45:18.799 So several observations about this behavior. First of all, they say, 0:45:18.840 --> 0:45:22.400 beaver's only picked up these display sticks or other objects 0:45:22.760 --> 0:45:25.719 at the same location where they were used, and they 0:45:25.719 --> 0:45:28.799 were never seen modifying the objects, So it wouldn't It 0:45:28.840 --> 0:45:31.160 wasn't like they would carry a stick around and then 0:45:31.239 --> 0:45:34.760 and then use it in a different location or modify 0:45:34.840 --> 0:45:35.800 the stick in any way. 0:45:36.120 --> 0:45:38.600 So, for instance, compare it to like human tool use 0:45:38.640 --> 0:45:42.520 that we've discussed in the past. Rocks. This this would 0:45:42.560 --> 0:45:45.640 not be on the level of picking out favored rocks 0:45:45.640 --> 0:45:49.919 for throwing at other humans, polishing them, changing them, etc. 0:45:50.239 --> 0:45:52.760 This would be more on the level of when threatened, 0:45:52.840 --> 0:45:55.000 you might look down, grab a rock and use it. 0:45:55.200 --> 0:45:56.719 Though of course, in this case, the beavers are not 0:45:56.800 --> 0:46:00.239 hitting each other with the sticks. Allegedly, the hypothesis here 0:46:00.320 --> 0:46:03.120 is that they're using them as a pure defensive display. 0:46:03.640 --> 0:46:07.719 Right. Second thing. This often happened in shallow water, so 0:46:07.760 --> 0:46:10.319 the shaking of the stick would cause splashing in the 0:46:10.360 --> 0:46:14.000 surrounding water, but occasionally it also took place on dry land, 0:46:14.120 --> 0:46:17.200 such as in weeds, where there was no significant sound produced. 0:46:17.560 --> 0:46:20.320 So the authors think because it took place in both 0:46:20.360 --> 0:46:23.160 scenarios and when it was on dry land it didn't 0:46:23.200 --> 0:46:25.600 really make a noise, they think it is primarily a 0:46:25.719 --> 0:46:29.200 visual signal. An important bit of context is that Eurasian 0:46:29.239 --> 0:46:33.880 beavers are territorial. They live in family groups with usually 0:46:33.920 --> 0:46:37.440 a dominant breeding pair and then assorted offspring of that 0:46:37.480 --> 0:46:41.080 breeding pair, and they defend the borders of their territory 0:46:41.120 --> 0:46:45.320 from encroachment by other beavers. So they mark their territory 0:46:45.360 --> 0:46:49.000 by scent. This is done with secretions from the anal 0:46:49.080 --> 0:46:53.440 glands or castorium. Which castorium, I believe, we'll talk about 0:46:53.440 --> 0:46:56.680 more later in the series in part two allegedly smells 0:46:56.680 --> 0:47:00.799 like vanilla, but we'll come back. When rival beavers come 0:47:00.920 --> 0:47:04.000 into a family group's territory, the home turf beavers will 0:47:04.040 --> 0:47:07.239 react first of all with tail slapping. Rob you mentioned this. 0:47:07.239 --> 0:47:10.400 This is a loud signal that beavers make by repeatedly 0:47:10.520 --> 0:47:13.440 smacking the water surface with their tails. This is also 0:47:13.560 --> 0:47:16.000 used to alert members of the family group when a 0:47:16.120 --> 0:47:20.320 predator is cited. They also respond to unwelcome beaver presence 0:47:20.680 --> 0:47:24.520 by visual displays or sometimes with actual fighting, though physical 0:47:24.520 --> 0:47:27.799 fights are relatively rare. The observations carried out in this 0:47:27.840 --> 0:47:33.640 study were conducted on wild Eurasian beavers in southeast Telemark, Norway. Overall, 0:47:34.040 --> 0:47:37.960 the researchers observed one hundred and thirty one cases of 0:47:38.120 --> 0:47:41.160 stick display behavior that met the criteria for inclusion in 0:47:41.200 --> 0:47:44.880 their study, by four adult males, two adult females, and 0:47:44.960 --> 0:47:51.160 five unidentified animals. However, it seems that some individual beavers 0:47:51.280 --> 0:47:55.040 engaged in stick displays far more than the others. 0:47:55.360 --> 0:47:55.840 Quote. 0:47:56.239 --> 0:47:59.920 It was clear from our observations that one female beer 0:48:00.520 --> 0:48:04.440 and one male Froda where the main performers, with a 0:48:04.440 --> 0:48:07.399 contribution of fifty one point nine percent and thirty five 0:48:07.480 --> 0:48:11.120 point nine percent, respectively of the total number of stick 0:48:11.160 --> 0:48:13.920 displays observed. So what does that add up to. It's 0:48:13.960 --> 0:48:16.680 like eighty seven percent of stick displays were from. 0:48:16.520 --> 0:48:19.360 Two beavers Wow, go Froda. 0:48:19.400 --> 0:48:21.760 But the real champion is beer Get here. She's got 0:48:21.760 --> 0:48:24.080 more than half of them just under her belt. 0:48:24.400 --> 0:48:26.640 Yeah yeah, I mean really, beer Get needs to get 0:48:27.000 --> 0:48:30.120 get most of the credit here for Froda doing pretty 0:48:30.160 --> 0:48:30.680 well as well. 0:48:30.960 --> 0:48:34.000 So they say. Stick displays happened almost exclusively at the 0:48:34.040 --> 0:48:38.640 borders of beaver family group territory, and most displays appear 0:48:38.719 --> 0:48:42.600 to be directed at rivals. The displays were often preceded 0:48:42.640 --> 0:48:46.280 by scent marking, so this kind of suggests it probably 0:48:46.360 --> 0:48:50.360 is being used as an agonistic display. However, this behavior, 0:48:50.520 --> 0:48:54.040 while common in the groups observed in this study, is 0:48:54.120 --> 0:48:58.360 not necessarily generalizable to the total world population of these beavers. 0:48:58.360 --> 0:49:01.880 It has not really been observed in beavers generally across 0:49:01.880 --> 0:49:06.560 the full range, suggesting it may be specific to certain populations. 0:49:07.040 --> 0:49:10.239 Wow like even some like some sort of like localized 0:49:10.239 --> 0:49:11.080 beaver culture. 0:49:11.480 --> 0:49:14.840 Yeah, maybe apparently something. At the time of the study, 0:49:14.920 --> 0:49:18.600 the author said there were some isolated reports of similar 0:49:18.640 --> 0:49:22.520 behavior in a few North American beavers, but not most, 0:49:22.640 --> 0:49:25.880 and it was not found in all Eurasian beavers either. 0:49:26.640 --> 0:49:29.680 So the authors argue that stick displays might be especially 0:49:29.719 --> 0:49:33.920 favored in high pressure situations. From reading their description of 0:49:33.960 --> 0:49:36.800 the of the area. It seems like the groups observed 0:49:36.800 --> 0:49:41.279 in this study might be in especially crowded beaver territory, 0:49:41.440 --> 0:49:45.440 where like, you know, the areas around different family dams 0:49:45.520 --> 0:49:49.000 and lodge sites are sort of all butting up against 0:49:49.040 --> 0:49:52.920 one another. They also observed higher rates of stick displays 0:49:52.920 --> 0:49:56.319 in springtime, meaning it's possible it could have some association 0:49:56.480 --> 0:50:00.680 with breeding. But if the stick shaking is a genuine 0:50:00.880 --> 0:50:05.719 agonistic display behavior, the evolutionary purpose would probably be to 0:50:05.880 --> 0:50:09.680 convey honest information about the beaver's size and strength. So 0:50:09.760 --> 0:50:12.080 it's like, I'm big and strong. Look at how I 0:50:12.120 --> 0:50:14.880 can shake this stick. You don't want to bother actually 0:50:14.880 --> 0:50:16.680 getting into a fight with me, right, we don't have 0:50:16.719 --> 0:50:17.200 to do this. 0:50:17.680 --> 0:50:20.959 I like these sort of levels of communication that seem 0:50:21.000 --> 0:50:24.319 to exist between beaver groups here. You know, It's like, 0:50:24.800 --> 0:50:27.399 at the end of the day, all beavers really want 0:50:27.440 --> 0:50:31.000 to do is build things and plug holes. You know, 0:50:31.080 --> 0:50:33.600 they have they have a lot of hole plugging to do. 0:50:34.200 --> 0:50:36.719 They have they have a lot of work to accomplish. 0:50:36.800 --> 0:50:38.439 They don't really have time to get into these fights. 0:50:38.480 --> 0:50:42.720 These fights are just would be destructive. So instead, let's 0:50:42.760 --> 0:50:44.960 just make sure that we're very clear about how everyone 0:50:45.000 --> 0:50:49.279 feels about these these border scenarios, and if need be, 0:50:49.520 --> 0:50:52.000 let me just show you, give you a taste of 0:50:52.000 --> 0:50:55.279 what could happen. Just look at this stick lifting ability here. 0:50:55.719 --> 0:50:58.840 The neighbors are getting nosy, and Beer get shakes a 0:50:58.880 --> 0:51:02.120 branch and it's like, no, don't make me do it. 0:51:02.200 --> 0:51:04.040 Don't make me do it. And it seems most of 0:51:04.080 --> 0:51:06.080 the time they're like, Okay, I won't make you do it, 0:51:06.080 --> 0:51:09.120 Beer gat Man. I think we've got to be out 0:51:09.120 --> 0:51:12.000 of time for part one of Beaver's here, right, but 0:51:12.040 --> 0:51:12.839 there will be more. 0:51:13.520 --> 0:51:15.600 Yeah, in the next episode, we're gonna we're going to 0:51:15.640 --> 0:51:18.960 get back to that idea, that that false idea of 0:51:19.080 --> 0:51:22.800 beavers whilst being hunted deciding to chew their own testicles 0:51:22.800 --> 0:51:27.839 off again that you see various examples of, particularly from 0:51:27.880 --> 0:51:31.279 like illuminated manuscripts and so forth and bestiaries. We'll come 0:51:31.320 --> 0:51:33.759 back and to discuss that, plus who knows what else 0:51:33.800 --> 0:51:37.840 we'll uncover about beavers in our research. In the meantime, 0:51:37.880 --> 0:51:39.520 we'd love to hear from everyone out there if you 0:51:39.600 --> 0:51:42.319 have any especially since a lot of times we do 0:51:42.360 --> 0:51:44.279 these Tuesdays to Thursday. This one's going to be a 0:51:44.280 --> 0:51:46.200 Thursday to Tuesday, so who knows, you might be able 0:51:46.200 --> 0:51:50.680 to get some really core beaver facts and beaver experiences 0:51:50.719 --> 0:51:54.400 into us before we record the next episode. You know, 0:51:54.560 --> 0:51:56.920 something you've picked up somewhere or just you know, accounts 0:51:56.960 --> 0:51:59.520 of observing beavers in the wild. I'd love to hear 0:51:59.560 --> 0:52:03.879 about that. So, whatever your feedback, whatever your thoughts, share 0:52:03.920 --> 0:52:05.759 them with us. We would love to hear from you. 0:52:06.320 --> 0:52:08.400 Just a reminder that Stuff to Blow Your Mind is 0:52:08.440 --> 0:52:11.759 a science podcast with core episodes on Tuesdays and Thursdays, 0:52:12.600 --> 0:52:14.040 so look for those in the Stuff to Blow your 0:52:14.080 --> 0:52:17.120 Mind podcast feed wherever you get your podcasts. On Mondays 0:52:17.160 --> 0:52:19.719 we do a listener mail episode. On Wednesdays we do 0:52:19.719 --> 0:52:22.839 a short form artifact or monster fact episode. I know 0:52:22.880 --> 0:52:26.600 sometimes people say I wish they were longer, Well they're short. 0:52:26.640 --> 0:52:29.759 That's part of how it works. But occasionally we're going 0:52:29.840 --> 0:52:32.640 to put out We're going to continue to experiment, experiment 0:52:32.640 --> 0:52:35.880 with putting out omnibus episodes that may take up like 0:52:36.040 --> 0:52:39.600 multiple related monster facts or artifacts and put them out 0:52:39.640 --> 0:52:42.200 so periodically you'll get a longer one in there as well. 0:52:42.880 --> 0:52:45.560 So yeah, let us know if you're liking that, and 0:52:45.640 --> 0:52:47.560 we can keep doing it. Oh, and then on Fridays 0:52:47.560 --> 0:52:50.040 we set aside most serious concerns to just talk about 0:52:50.040 --> 0:52:52.040 a weird movie on Weird House Cinema. 0:52:52.160 --> 0:52:55.680 Huge thanks to our audio producer JJ Posway. If you 0:52:55.680 --> 0:52:57.800 would like to get in touch with us with feedback 0:52:57.840 --> 0:53:00.480 on this episode or any other, to suggest topic for 0:53:00.520 --> 0:53:02.800 the future, or just to say hello, you can email 0:53:02.880 --> 0:53:13.439 us at contact at stuff to Blow your Mind dot com. 0:53:13.440 --> 0:53:16.400 Stuff to Blow Your Mind is production of iHeartRadio. For 0:53:16.480 --> 0:53:20.320 more podcasts from iHeartRadio, visit the iHeartRadio app, Apple Podcasts, 0:53:20.400 --> 0:53:36.400 or wherever you listen to your favorite shows.