WEBVTT - Christmas Island, Part 1: Crabs Rule Everything Around Me 0:00:03.320 --> 0:00:06.040 Towards the Island of Christmas, and all across the land 0:00:06.200 --> 0:00:09.240 the red crabs were flowing across root Street and sand 0:00:09.880 --> 0:00:13.560 like a red tide of scuttling, claw snapping doom. They 0:00:13.600 --> 0:00:17.200 streamed through my front door and into my rooms. Meanwhile, 0:00:17.280 --> 0:00:21.479 in the forests the giants, they're crawled coconut crabs, hulking 0:00:21.520 --> 0:00:26.080 monsters with claws. They hunted for carrion crab bird and 0:00:26.160 --> 0:00:35.440 ratted and gobbled it up, rancid, sinew and fat. Welcome 0:00:35.440 --> 0:00:38.120 to Stuff to Blow your Mind from how Stuff Works 0:00:38.120 --> 0:00:46.800 dot Com. Hey, welcome to Stuff to Blow your Mind. 0:00:46.880 --> 0:00:49.440 My name is Robert Lamb, and I'm Joe McCormick, and 0:00:49.479 --> 0:00:52.000 getting in that holiday spirit. We're gonna be talking about 0:00:52.040 --> 0:00:56.400 crab Horror. Yes, this is this pair of episodes. I've 0:00:56.400 --> 0:00:59.319 been looking forward to all year. This has been my 0:00:59.440 --> 0:01:02.280 my goal. I forget when, but earlier in the year 0:01:02.640 --> 0:01:05.840 I was reading about Christmas Island and and the various 0:01:06.280 --> 0:01:09.400 creatures that that call it home, and I realized, we 0:01:09.600 --> 0:01:12.200 have to do this episode for Christmas, even though this 0:01:12.319 --> 0:01:15.120 really has nothing to do with Christmas, no, virtually nothing 0:01:15.160 --> 0:01:18.520 to do with Christmas, though I do enjoy um like 0:01:18.640 --> 0:01:23.920 forcing decapods upon Christmas and uh and and and at 0:01:23.959 --> 0:01:26.000 least in my mind, allowing them to take over the 0:01:26.040 --> 0:01:30.120 holiday decapods with bows of all? Is it bows? I 0:01:30.160 --> 0:01:34.040 should have said clause of glory? Either way, I appreciate 0:01:34.160 --> 0:01:37.640 the holiday zeal. Now, so we're going to be going 0:01:38.040 --> 0:01:42.280 to crab Horror Island, and there are many wonderful movies 0:01:42.360 --> 0:01:44.119 and maybe we'll save it for next time to talk 0:01:44.160 --> 0:01:47.520 about our favorite Crab Island movies. But the giant crab 0:01:47.640 --> 0:01:49.520 is one of my favorite kind of movie monsters, and 0:01:49.520 --> 0:01:51.880 they've always got to have their own island of terror, 0:01:52.000 --> 0:01:55.280 right right, and and so in discussing Christmas Island and 0:01:55.320 --> 0:01:58.360 these two episodes, we're going to talk about crabs or 0:01:58.440 --> 0:02:03.800 you know, decapods anyway that are either enormous, uh, singularly 0:02:03.800 --> 0:02:07.360 and enormous or collectively enormous. I think the first episode 0:02:07.360 --> 0:02:09.920 we're going to focus on the collectively enormous, and the 0:02:09.960 --> 0:02:15.040 second episode will focus on the decapods who are individually enormous. Now, 0:02:15.200 --> 0:02:18.160 this first episode is going to focus on the Christmas 0:02:18.160 --> 0:02:20.920 Island Red crab. Robert, will you take me on a 0:02:20.960 --> 0:02:25.160 mystical adventure to crab Horror Island? Yes, we're talking about 0:02:25.240 --> 0:02:28.680 Christmas Island, so named. It's in the Indian Ocean, about 0:02:28.760 --> 0:02:31.200 three hundred and fifty kilometers or two hundred and twenty 0:02:31.240 --> 0:02:36.000 miles south of Java and Sumatra and around uh, let's 0:02:36.040 --> 0:02:39.400 see one thou fifty kilometers or nine hundred and sixty 0:02:39.440 --> 0:02:43.200 miles northwest of the closest point on the Australian mainland. 0:02:43.480 --> 0:02:46.760 Technically part of Australia though right it is an Australian 0:02:46.800 --> 0:02:50.440 external territory. It has an area of a hundred five 0:02:50.440 --> 0:02:53.720 square kilometers or fifty two square miles, so not huge, No, 0:02:53.880 --> 0:02:56.200 not a big place at all. It's a very old, 0:02:56.200 --> 0:03:01.280 though very old volcanic seamount island. It was first visited 0:03:01.320 --> 0:03:06.320 by Europeans in sixty three Captain William Minors of the 0:03:06.400 --> 0:03:09.760 Royal Mary and English East India Company vessel. He just 0:03:09.840 --> 0:03:12.160 named the island when he sailed past it on Christmas 0:03:12.280 --> 0:03:15.720 Day of that year. That's that's the only Christmas high 0:03:15.840 --> 0:03:19.120 end there he didn't find, you know, and naturally occurring 0:03:19.240 --> 0:03:23.040 Christmas tree there. Uh, there's no wasn't where the elf 0:03:23.080 --> 0:03:26.440 workshop was exactly. There's there's nothing else about it except 0:03:26.560 --> 0:03:28.399 it was Christmas Day when he found it. It could 0:03:28.400 --> 0:03:30.040 have easily it could have easily turned out to be 0:03:30.240 --> 0:03:34.880 Christmas Eve Island or Boxing Day Island or Halloween Island. 0:03:34.920 --> 0:03:39.080 That would perhaps be a little more appropriate. Yeah. Uh So. 0:03:39.560 --> 0:03:41.960 One of the cool things about this place is that 0:03:42.080 --> 0:03:44.560 when when they were able to take a closer look 0:03:44.560 --> 0:03:47.720 at it, they realized that it was uninhabited, at least 0:03:47.720 --> 0:03:51.120 by humans. So it's obvious that what makes this island 0:03:51.200 --> 0:03:54.840 unique is not anything about the indigenous culture or anything, 0:03:54.920 --> 0:03:58.560 since it was apparently uninhabited originally, but it was not 0:03:58.640 --> 0:04:01.880 uninhabited by wildlife. Fest we've made clear the wildlife there 0:04:02.280 --> 0:04:05.800 was of a terrific scuttling variety, oh correct. And one 0:04:05.840 --> 0:04:08.080 of the really cool things about the scuttling life on 0:04:08.160 --> 0:04:10.040 Christmas Island it is that so much of it is 0:04:10.120 --> 0:04:13.680 on Christmas Island. We're talking about land crabs, crabs that 0:04:13.720 --> 0:04:16.320 need only returned to the water to mate, but mostly 0:04:16.400 --> 0:04:19.640 live on land. And you'll find these elsewhere. To be sure, 0:04:19.680 --> 0:04:23.120 this is not the only place land crabs can be found. 0:04:23.520 --> 0:04:26.840 Uh And we're we're talking about both true crabs as 0:04:26.880 --> 0:04:30.400 well as hermit crabs here. Hermit crabs are decapods, but 0:04:30.480 --> 0:04:34.479 not true crabs. But forgive us as we as we 0:04:34.480 --> 0:04:36.440 talk about them in these episodes, I will probably end 0:04:36.480 --> 0:04:39.760 up calling them both crabs in the unofficial sense. The 0:04:39.880 --> 0:04:43.360 Christmas Island is home to more land crabs than anywhere 0:04:43.360 --> 0:04:46.400 else on Earth. We're talking more than twenty terrestrial and 0:04:46.440 --> 0:04:50.200 semi terrestrial crabs species, plus a hundred and sixties species 0:04:50.279 --> 0:04:53.680 or thereabouts in the reefs and shallows around the island. Yeah, 0:04:53.680 --> 0:04:56.400 so Robert tell me a little bit about crabs. Well, 0:04:56.520 --> 0:05:00.000 just to refresh everybody, crabs are crustaceans. But we should 0:05:00.080 --> 0:05:02.960 be clear that again, there are true crabs of the 0:05:03.080 --> 0:05:07.520 decapoda soap order bracci ura, which means small tail um, 0:05:07.600 --> 0:05:11.160 which references their smaller abdomen. And then there are the 0:05:11.360 --> 0:05:15.160 ano mora or mixed tail crabs, which included hermits and 0:05:15.240 --> 0:05:18.040 as we'll discuss later in the second episode, robber crabs. 0:05:18.839 --> 0:05:21.520 But still again we're often going to refer to them 0:05:21.520 --> 0:05:25.320 both as crabs in the unofficial sense. And these were 0:05:25.360 --> 0:05:27.680 these are ancient creatures. These were the first animals to 0:05:27.720 --> 0:05:32.520 develop true legs, none of those false legs. Yeah, I mean, 0:05:32.760 --> 0:05:34.520 we we've talked about crabs on the show before. I 0:05:34.520 --> 0:05:36.960 think back to our episode about Carl Sagan and the 0:05:36.960 --> 0:05:41.159 Samurai Crabs. So so hopefully everyone is is on board 0:05:41.200 --> 0:05:44.919 for two more episodes of of crab based content. But 0:05:45.040 --> 0:05:48.960 so it's not just the varieties of crab and crab 0:05:49.040 --> 0:05:52.280 like creatures that live on Christmas Island that make it 0:05:52.440 --> 0:05:56.839 crab Island Earth, Uh, it is is the number of 0:05:56.920 --> 0:06:01.000 a particular species of crab there, the Christmas Silelan red crab, 0:06:01.480 --> 0:06:06.520 where there are supposedly tens of millions of these crabs 0:06:06.640 --> 0:06:08.760 on the island. And this is not a big island. Remember, 0:06:08.760 --> 0:06:12.080 it's a hundred thirty five square kilometers, right, a small island. 0:06:12.080 --> 0:06:13.920 And yet yeah, I've seen the figures of like fifty 0:06:13.960 --> 0:06:17.839 million of these creatures living, living in the forest, living, 0:06:18.279 --> 0:06:20.160 you know, pretty much all over the island. And that's 0:06:20.160 --> 0:06:23.640 a reduced number. I remember we watched a documentary about 0:06:23.640 --> 0:06:26.040 the island from the nineteen eighties that suggested, at the 0:06:26.080 --> 0:06:28.159 time it was believed that there were over a hundred 0:06:28.240 --> 0:06:31.279 million of the crabs. They're right. That was a night 0:06:31.680 --> 0:06:36.839 David Attenborough narrated special titled Kingdom of the Crab, great title, 0:06:37.080 --> 0:06:38.599 and that's a great one to watch if you get 0:06:38.600 --> 0:06:41.200 a chance, because it really shows off what makes this 0:06:41.360 --> 0:06:46.000 island visually astounding, but it's the sheer numbers of the 0:06:46.040 --> 0:06:48.960 crabs and the Christmas Island red crab is pretty much 0:06:49.040 --> 0:06:52.520 found only on Christmas Island. Yeah, I think maybe on 0:06:52.600 --> 0:06:55.600 another nearby island or island group, but they're not found 0:06:55.680 --> 0:06:58.080 like all over the place. So I do want to 0:06:58.080 --> 0:06:59.840 come back to the human history for a little bit 0:07:00.040 --> 0:07:04.480 where we we explore the red uh crab in depth. 0:07:04.800 --> 0:07:07.160 So the most you know, essential thing about human history 0:07:07.160 --> 0:07:09.520 of Christmas Island is that for the longest there seems 0:07:09.600 --> 0:07:13.000 to have been none. It is a geographically isolated place 0:07:13.760 --> 0:07:16.880 now from everything I've read so far, and it's always 0:07:16.880 --> 0:07:20.560 possible on missing something, but there's no evidence that humans 0:07:20.600 --> 0:07:24.480 ever visited the place before the seventeenth century. See this. 0:07:24.560 --> 0:07:28.520 Despite Java being again only two miles away, it's a 0:07:28.560 --> 0:07:31.600 short enough distance for modern humans anyway that boats of 0:07:31.640 --> 0:07:35.600 asylum seekers frequently make it their point of destination in 0:07:35.640 --> 0:07:39.080 reaching Australia, because again it's an Australian external territory, So 0:07:39.120 --> 0:07:41.480 if you reach Christmas Island, you are, you know, in 0:07:41.520 --> 0:07:45.640 a legal sense, in Australia. However, it's also worth pointing 0:07:45.680 --> 0:07:49.120 out that the seas can be deadly uh, surrounding Christmas Island, 0:07:49.120 --> 0:07:51.840 and there are stories out there boats of asylum seekers 0:07:51.920 --> 0:07:54.760 breaking on the rocky coast with lethal results. I think 0:07:54.760 --> 0:07:57.560 I've read about this in cases of the early visitors 0:07:57.600 --> 0:07:59.720 to the island. Also that you know, it was kind 0:07:59.760 --> 0:08:03.160 of dangerous to land there. And for example, there was 0:08:03.240 --> 0:08:05.520 one case where I read that a crew was driven 0:08:05.560 --> 0:08:07.960 to land there because there was scurvy on the ship 0:08:08.000 --> 0:08:10.280 and it was only because the disease had gotten so 0:08:10.360 --> 0:08:13.240 bad that they risked trying to land. Yeah, that's sort 0:08:13.240 --> 0:08:16.120 of the typical story book reasons for landing on an 0:08:16.200 --> 0:08:20.400 uninhabited island with a strange crab population. Yeah, but out 0:08:20.440 --> 0:08:23.440 of the scurvy pan into the crabs. Yeah, and you 0:08:23.480 --> 0:08:25.200 know it, but but it is. It is weird to 0:08:25.480 --> 0:08:28.440 think about places like this, places where where humans just 0:08:28.560 --> 0:08:31.680 didn't take up residents. And of course you have to, 0:08:32.120 --> 0:08:36.280 of course realize that moving to an isolated island is 0:08:36.320 --> 0:08:39.080 a difficult proposition, like you've really got to have a 0:08:39.080 --> 0:08:41.120 reason to go there and a reason to stay there, 0:08:41.840 --> 0:08:45.559 and a way to um to to safely arrived there 0:08:45.600 --> 0:08:48.319 as well. But still, you know, it's enough to make 0:08:48.320 --> 0:08:51.640 one wonder. For instance, Homo Erectus or a Java Man 0:08:51.800 --> 0:08:55.480 lived on the island of Java, relatively close by one 0:08:55.520 --> 0:08:59.440 point seven million years ago. Humans practiced agriculture there on 0:08:59.559 --> 0:09:04.280 Java as early as b C. Java was known to 0:09:04.320 --> 0:09:08.199 traders and other powers. The Kingdom of Mataram ruled there 0:09:08.240 --> 0:09:10.680 until they lost power to the Dutch East India Company 0:09:10.720 --> 0:09:14.280 in seventy nine and became a vassal state of the 0:09:14.320 --> 0:09:18.840 company UM, a statement that I think really drives home 0:09:18.960 --> 0:09:22.600 the power of the East India Company UM, the idea 0:09:22.640 --> 0:09:26.040 that you would have a vassal state to a corporation. 0:09:26.880 --> 0:09:28.880 But that's a job. My point is that I just 0:09:28.880 --> 0:09:31.679 find it so enthralling that this island remained either free 0:09:31.679 --> 0:09:35.559 of human contact for so long or only encountered minimal influence. 0:09:35.600 --> 0:09:37.520 You know. It's I guess it's possible that it's at 0:09:37.559 --> 0:09:41.360 some point somebody wound up there by purpose or accident 0:09:41.600 --> 0:09:45.319 and didn't didn't stay long enough to leave a footprint, 0:09:46.000 --> 0:09:48.920 you know. Galapagos Islands or another example of this, though 0:09:48.960 --> 0:09:52.360 there there have been at least disputed claims of Inca 0:09:52.480 --> 0:09:55.680 artifacts found on the Galapacos Islands, perhaps due to Inca 0:09:55.760 --> 0:09:59.800 sailors being blown off course. The statials in the Indian 0:09:59.800 --> 0:10:02.400 Ocean and are another example of islands that were uninhabited 0:10:02.400 --> 0:10:05.080 through most of recorded history, though they may have been 0:10:05.200 --> 0:10:07.680 visited by early seafares as well, depending on who you 0:10:07.679 --> 0:10:10.679 talked to. But with Christmas Island, I found no such thing, 0:10:10.960 --> 0:10:14.680 and not even a crackpot theory. So it really does 0:10:14.720 --> 0:10:17.319 seem as if humans, not even the Vikings, went their 0:10:17.400 --> 0:10:19.760 theory by no Vikings or anything. So it really does 0:10:19.760 --> 0:10:22.400 seem that nobody visited it until the seventeenth century, with 0:10:22.520 --> 0:10:26.840 the earliest sighting I think having occurred in sixteen fifteen. 0:10:27.200 --> 0:10:30.160 Now after that, of course, it actually did become an 0:10:30.160 --> 0:10:34.880 economically significant island because of mineral deposits discovered there. That's right. 0:10:34.920 --> 0:10:38.600 It was explored by British naturalist John Murray, and this 0:10:38.800 --> 0:10:43.000 was eighteen seventy two. He discovered that there were phosphate 0:10:43.040 --> 0:10:46.080 deposits on the island, which would play a key role 0:10:46.120 --> 0:10:49.760 in the island's future. Exportation of phosphate begin in eighteen 0:10:51.080 --> 0:10:54.679 by the Christmas Island Phosphate Company, and this activity led 0:10:54.720 --> 0:10:58.120 to the loss of twenty of the island's rainforest area. Yeah, Now, 0:10:58.160 --> 0:11:01.040 phosphate was important in the late eight hundreds because it 0:11:01.120 --> 0:11:04.560 had been discovered by that time that phosphate, when treated 0:11:04.600 --> 0:11:07.600 with sulfuric acid, could be used as an ingredient in 0:11:07.720 --> 0:11:11.440 plant food, and of course synthetic fertilizers became very important 0:11:11.440 --> 0:11:14.600 in the development of commercial agriculture at scale, and so 0:11:14.640 --> 0:11:17.520 now there was a reason and economic reason for people 0:11:17.559 --> 0:11:21.880 to not only go to Christmas Island but to work there, 0:11:22.440 --> 0:11:26.280 and so settlement began in the eighteen eighties. Uh later on, 0:11:26.679 --> 0:11:29.160 during the Second World War there was a Japanese occupation 0:11:29.160 --> 0:11:33.280 of the island from ninety five, and in the post 0:11:33.280 --> 0:11:36.400 war period it was administered by Singapore, which was then 0:11:36.440 --> 0:11:39.720 a British colony, and then Australia purchased the island for 0:11:39.760 --> 0:11:43.280 two point nine million pounds on January one, nineteen fifty 0:11:43.400 --> 0:11:47.040 eight day that's known as Territory Day on Christmas Island. 0:11:48.320 --> 0:11:51.640 Today it has around I've read two thousand full time 0:11:52.080 --> 0:11:56.440 human residents and the ethnic makeup is mostly Chinese in 0:11:56.559 --> 0:11:59.760 meleay Um originally brought in for labor. Now a big 0:11:59.760 --> 0:12:02.600 poor scan of the land of the island today is 0:12:03.080 --> 0:12:08.000 basically a national park. It's like a big wildlife preservation area. Yeah, 0:12:08.000 --> 0:12:11.120 two thirds of its land mass are national park. Now, 0:12:11.200 --> 0:12:13.680 and a big part of the wildlife significance here is 0:12:13.760 --> 0:12:16.160 the Christmas Island red crabs. So I guess we should 0:12:16.200 --> 0:12:19.319 dive headfirst into a puddle of crabs after we come 0:12:19.360 --> 0:12:24.760 back from a break. Alright, we're back, so it is 0:12:24.800 --> 0:12:27.960 time to dive into a pit of crabs. The Christmas 0:12:28.000 --> 0:12:32.520 Island red crab or get Karcodia natalis. And these are 0:12:32.520 --> 0:12:35.720 crabs that live, as we mentioned earlier, primarily not in 0:12:35.760 --> 0:12:39.920 the ocean, not even on the shoreline, but in inland forests. 0:12:40.080 --> 0:12:42.720 So if you picture Christmas Island, it's sort of a 0:12:42.840 --> 0:12:47.160 terraced rainforest. It's a you know, volcanic island. It's got 0:12:47.240 --> 0:12:51.600 some steep slopes that go up onto rainforest covered terraces, 0:12:51.640 --> 0:12:53.720 and the crabs go all the way up into the 0:12:53.800 --> 0:12:57.400 forests and make their burrows inland. Yeah, we're talking against 0:12:57.400 --> 0:12:59.959 something like fifty million of these a little land well 0:13:00.160 --> 0:13:04.240 ers uh in the forest chewing up leaf litter. And 0:13:04.280 --> 0:13:07.280 here on Christmas Island they are the chief decay agents 0:13:07.320 --> 0:13:10.480 for that leaf litter. I've seen estimates of something like 0:13:10.559 --> 0:13:14.280 four thousand crabs per acre to keep the leaf litter down. Yes, 0:13:14.320 --> 0:13:17.400 and they primarily feed on plant matter like you say, 0:13:17.440 --> 0:13:19.560 so that is going to be leaf litter. It's also 0:13:19.640 --> 0:13:24.360 things like fallen fruits and seeds, flowers, et cetera. But 0:13:24.679 --> 0:13:27.240 they're also crabs after all, so you might not be 0:13:27.360 --> 0:13:31.640 surprised to learn that they are opportunistic omnivores. My favorite 0:13:31.640 --> 0:13:34.640 pairs of words. So if you get a little bit 0:13:34.679 --> 0:13:37.560 of meat from say another dead red crab or something 0:13:37.600 --> 0:13:40.640 like that presenting itself, this is a legitimate score, and 0:13:40.679 --> 0:13:43.320 they will say, gentlemen, get that in my mouth parts. 0:13:43.440 --> 0:13:46.960 It's time to masticate. But the crabs are important for 0:13:47.000 --> 0:13:49.840 the maintenance of the ecosystem in multiple ways. So they 0:13:49.880 --> 0:13:52.920 clear the forest floor of like leaf litter, but also 0:13:53.000 --> 0:13:58.040 saplings and flowers other plants that would create dense underbrush, 0:13:58.120 --> 0:14:00.400 and so they keep the forest floors lean, and this 0:14:00.480 --> 0:14:05.000 actually helps contribute to forest biodiversity. They also prevent the 0:14:05.120 --> 0:14:08.360 soil from being packed too densely because of the burrows 0:14:08.400 --> 0:14:12.640 they dig. They're like natural soil tillers. They turn the soil, 0:14:13.200 --> 0:14:17.320 and this also helps contribute to forest biodiversity. But so 0:14:17.400 --> 0:14:19.600 we might have a pretty good sense of what the 0:14:19.680 --> 0:14:22.320 life of an ocean dwelling crab is like. What is 0:14:22.360 --> 0:14:25.160 the life of a land crab like crabs, as you 0:14:25.160 --> 0:14:27.920 can imagine, in between chewing up things in their environment 0:14:27.960 --> 0:14:30.720 and eating it, they have to stay moist and this means, 0:14:30.760 --> 0:14:33.000 for one thing, staying out of the direct sun. So 0:14:33.040 --> 0:14:35.760 the red crabs on Christmas Island like to stay in 0:14:35.760 --> 0:14:38.800 the shady forests and they live in these dugout burrows 0:14:38.840 --> 0:14:41.400 that they can hide from the sun in and they 0:14:41.400 --> 0:14:45.040 have guilt chambers that have adapted for terrestrial life. They 0:14:45.080 --> 0:14:47.240 have to keep them moist, and they also I love this, 0:14:47.320 --> 0:14:49.840 they have to manually wet their eye stalks. Yes, I 0:14:49.880 --> 0:14:51.640 love this. It's pretty cool to watch if you can 0:14:51.680 --> 0:14:54.960 find video of this. So their eyes talks emerge from 0:14:55.040 --> 0:14:58.720 little cups in their carapace, and they don't have eyelids 0:14:58.760 --> 0:15:01.000 of course, and by the way, just try to imagine 0:15:01.040 --> 0:15:05.200 life without eyelids. Kind of a terror. So they wet 0:15:05.320 --> 0:15:09.000 and wash their eyes by filling their eye cups up 0:15:09.040 --> 0:15:12.760 with drops of water and then dipping their eyestalks down 0:15:12.840 --> 0:15:16.720 into the cups to rinse them off. Yeah. I think 0:15:16.760 --> 0:15:18.120 this is This is one of the great things about 0:15:18.120 --> 0:15:22.120 watching any crab close up, but especially with the Christmas 0:15:22.120 --> 0:15:25.400 crabs is those tiny little sort of methodical movements that 0:15:25.440 --> 0:15:27.920 you see take place with their mouth parts and their 0:15:28.000 --> 0:15:31.960 their eyes stalks totally. Now, despite their life in the woods, 0:15:32.120 --> 0:15:34.480 they still have to return to the sea to spawn, 0:15:34.880 --> 0:15:38.440 and this results in a vast scuttling migration that is 0:15:38.520 --> 0:15:41.720 truly unlike anything else on earth. This is why you 0:15:41.760 --> 0:15:43.880 will you will see. You know, there's so many different 0:15:44.800 --> 0:15:47.280 documentaries about Christmas Island. That's why there's so much great 0:15:47.280 --> 0:15:52.440 footage because they they go on these enormous migrations and 0:15:52.440 --> 0:15:56.040 we're talking a several kilometer journey each year. Yeah, this 0:15:56.120 --> 0:15:59.160 is crab Apocalypse. This is where the real show is 0:15:59.240 --> 0:16:02.480 on Christmas Eye. And so around the beginning of the 0:16:02.560 --> 0:16:06.560 rainy season, which is sometime October through December, the red 0:16:06.600 --> 0:16:10.560 crabs begin this migration for their breeding cycle. And the 0:16:10.640 --> 0:16:14.280 migration begins with the males, usually the biggest males, who 0:16:14.320 --> 0:16:17.760 will crawl out over land from their forest burrows to 0:16:17.920 --> 0:16:21.400 the shore where they're going to eventually get there and 0:16:21.480 --> 0:16:24.840 dig new burrows for mating. And as the males make 0:16:24.920 --> 0:16:27.680 this journey, the females eventually joined them in the journey 0:16:27.760 --> 0:16:30.800 and they march towards the sea. Now, once the crabs 0:16:30.840 --> 0:16:34.400 reached the shore, but before they dig their burrows to mate, uh, 0:16:34.560 --> 0:16:38.600 they typically wash themselves off in seawater, though strangely enough, 0:16:38.840 --> 0:16:41.240 they have to be careful not to get fully sucked 0:16:41.240 --> 0:16:44.480 out into the sea because these are land dwelling crabs. 0:16:44.560 --> 0:16:47.880 This is how they've evolved, and they can neither breathe underwater, 0:16:48.040 --> 0:16:50.920 nor can they swim very well. These are crabs who 0:16:50.920 --> 0:16:54.640 are not very good at being crabs. Yeah, so the 0:16:54.920 --> 0:16:58.040 truly aquatic crabs in the neighborhood are just probably watching 0:16:58.040 --> 0:17:01.840 this in halfing at them. But there's so many of them. 0:17:01.840 --> 0:17:03.600 How could you laugh at them? Because they could really 0:17:03.600 --> 0:17:05.119 gang up on you if they got a hold of 0:17:05.160 --> 0:17:08.399 your right But so they would rinse themselves off in 0:17:08.400 --> 0:17:11.440 the sea water. And then the males dig the burrows. Now, 0:17:11.480 --> 0:17:14.199 sometimes when they dig the burrows, usually they'll go up 0:17:14.200 --> 0:17:16.960 a little bit from the beach and one of the 0:17:17.400 --> 0:17:20.520 forested areas just right by the beach, and they'll dig 0:17:20.520 --> 0:17:23.040 these burrows. And sometimes the males have to defend their 0:17:23.080 --> 0:17:25.320 burrows from other males, who of course think, hey, why 0:17:25.440 --> 0:17:28.000 dig one when you can just claim somebody else's. So 0:17:28.040 --> 0:17:31.040 there are sometimes these fights and dominance displays, a lot 0:17:31.080 --> 0:17:34.560 of claw waving to keep the burrows secure, and then 0:17:34.760 --> 0:17:36.720 of course the females come in and they will find 0:17:36.720 --> 0:17:39.840 a male with a burrow and initiate the mating. And 0:17:39.920 --> 0:17:43.320 by the way, if you've never watched crabs mating before, 0:17:43.960 --> 0:17:47.879 it's one of the funnier looking types of animal sex. 0:17:47.920 --> 0:17:50.520 I think it's just crabs look funny no matter what 0:17:50.560 --> 0:17:54.280 they're doing. But also if you can just watch their 0:17:54.400 --> 0:17:58.040 eyes while they're mating, it's really something special. It's you know, 0:17:58.119 --> 0:18:00.879 it's like two googly eyed robots trying to be sexy 0:18:00.920 --> 0:18:03.680 at each other and then throwing some claws and swiveling 0:18:03.720 --> 0:18:06.680 mouth parts. It's just awesome. Now you mentioned the waving 0:18:06.680 --> 0:18:08.159 of the clause, I want to I was reading a 0:18:08.200 --> 0:18:11.000 little bit about crab clause in Douglas j Imland's book 0:18:11.040 --> 0:18:13.400 Animal Weapons. Uh and he goes. He spends a little 0:18:13.400 --> 0:18:15.159 bit of time talking about, you know, how these are 0:18:15.240 --> 0:18:19.280 high energy adaptations packed with powerful muscles. They need to 0:18:19.280 --> 0:18:22.280 be able to break through the exo skeletons of of 0:18:22.400 --> 0:18:25.840 rival males in many cases. Uh And he mostly looks 0:18:25.840 --> 0:18:28.320 at fiddler crabs in this book. But but, but it's 0:18:28.359 --> 0:18:32.600 interesting stuff. The economics of not only having growing, evolving 0:18:32.640 --> 0:18:36.520 gigantic class, but waving them around, because that's that's part 0:18:36.600 --> 0:18:39.320 of having the cleaving clause or a claw, is to 0:18:39.520 --> 0:18:44.080 wave that sucker around, yeah, or like flexing your muscles, 0:18:44.160 --> 0:18:46.280 like showing off the guns. Yeah, you have to show 0:18:46.320 --> 0:18:49.840 off the guns. That's that's part of having them, right. Yeah. 0:18:49.880 --> 0:18:53.960 So the female will generally find a male and a 0:18:54.000 --> 0:18:55.880 male with the borrow and they will mate, and then 0:18:55.960 --> 0:18:58.240 after mating, what the males do is they just pack 0:18:58.359 --> 0:19:01.080 up and headback inland. Their work is done, and they 0:19:01.200 --> 0:19:05.359 leave the females by themselves in the seaside burrows. And 0:19:05.880 --> 0:19:08.680 there's another interesting thing about this. Okay, so the red 0:19:08.720 --> 0:19:13.639 crabs are sort of moon worshiping druids. The breeding migration 0:19:13.760 --> 0:19:16.959 has to be timed exactly according to the cycle of 0:19:16.960 --> 0:19:20.480 the moon because the cycle of the moon affects the tides. 0:19:21.000 --> 0:19:23.520 So the adult crabs arrive at the shore and then 0:19:23.560 --> 0:19:26.400 they mate, and after mating, the females produce eggs within 0:19:26.440 --> 0:19:29.760 about three days, and then they remain in their burrows 0:19:29.800 --> 0:19:33.800 for another twelve or thirteen days. And after this they 0:19:33.840 --> 0:19:36.360 emerge from the hole in the ground and they release 0:19:36.440 --> 0:19:38.600 their eggs into the sea water. And it has to 0:19:38.640 --> 0:19:41.480 be timed exactly at the turn of high tide as 0:19:41.520 --> 0:19:44.560 the moon goes from its last quarter to a new moon. 0:19:45.080 --> 0:19:47.719 And this is because it's when the tide conditions are 0:19:47.800 --> 0:19:50.919 just right to be releasing uh the young. But if 0:19:50.960 --> 0:19:54.359 the migration is delayed by weather so that breeding can't 0:19:54.359 --> 0:19:56.680 be timed exactly right with the phases of the moon, 0:19:56.720 --> 0:19:58.919 the crabs will just wait. They'll just wait until the 0:19:58.960 --> 0:20:01.800 next month to breed because it's not it's not going 0:20:01.880 --> 0:20:04.760 the moon isn't right. So when the time is right, 0:20:05.000 --> 0:20:07.879 the females release their eggs acts, which looks kind of 0:20:07.920 --> 0:20:10.480 like a weird foamy sponge that they carry on the 0:20:10.560 --> 0:20:13.320 underside of their bodies. They release these eggs acts into 0:20:13.320 --> 0:20:16.800 the water. Yet again, I can't help but notice that 0:20:16.880 --> 0:20:20.280 my wonder at these animals is combined with hilarity on 0:20:20.359 --> 0:20:23.320 seeing this, because in some cases, the female crabs have 0:20:23.400 --> 0:20:26.480 to release their eggs into like rough surf while clinging 0:20:26.520 --> 0:20:29.119 to rocks above the water, and they're trying to be 0:20:29.160 --> 0:20:31.400 careful not to fall in. And when you see footage 0:20:31.400 --> 0:20:34.760 of this, the way they're just frantically shaking their bodies 0:20:34.840 --> 0:20:38.080 to knock the eggs acts off, dumping thousands of eggs 0:20:38.080 --> 0:20:41.160 off a cliff. I can't help but laugh. It's funny. 0:20:41.200 --> 0:20:43.879 And then also sometimes they'll they'll go into the surf 0:20:43.960 --> 0:20:46.440 on a beach and you'll see them like raising their 0:20:46.480 --> 0:20:52.000 claws and shaking their bodies, like get off, just dumping 0:20:52.040 --> 0:20:53.919 all these eggs off into the water. I don't know, 0:20:54.000 --> 0:20:58.480 it's it's funny to me. Well, by human comparisons, they're 0:20:58.480 --> 0:21:01.399 maybe not great moms, but by but by Christmas Island 0:21:01.440 --> 0:21:05.000 Red Crab standards, moms of the Year. Yeah, exactly, and 0:21:05.280 --> 0:21:07.280 that this does make me think about the ways that 0:21:07.320 --> 0:21:09.840 we anthropomorphize good parenting. I want to come back to 0:21:09.880 --> 0:21:12.600 that in just a minute. So the eggs are released 0:21:12.600 --> 0:21:15.280 into the surf and they hatch pretty much immediately, and 0:21:15.280 --> 0:21:18.200 then you've got these hatchling crab larvae that live in 0:21:18.240 --> 0:21:22.320 the water for about a month, transforming through large larval stages, 0:21:22.400 --> 0:21:26.560 and then they returned the shore in this seething foam 0:21:26.800 --> 0:21:29.919 of what looks like pink ants. This is also just 0:21:30.000 --> 0:21:33.399 astonishing to see, like the original migration from the forest 0:21:33.440 --> 0:21:36.800 to the shore with the beaches and rocks covered in 0:21:36.880 --> 0:21:42.760 this surging pink shag carpet of tiny millimeter sized baby crabs. 0:21:43.160 --> 0:21:46.199 And then they molt, and immediately after molting, they they 0:21:46.200 --> 0:21:49.159 are committed to an air breathing life on land, and 0:21:49.200 --> 0:21:52.680 they travel inland to do as their ancestors did before them. 0:21:52.720 --> 0:21:55.720 And this growth from about a five millimeter baby crab 0:21:55.800 --> 0:21:58.880 stage to adulthood usually takes about four years, during which 0:21:58.920 --> 0:22:01.959 time they mostly tend to hide out undercover until they 0:22:02.000 --> 0:22:05.080 get big enough to fend for themselves. But yeah, back 0:22:05.080 --> 0:22:08.520 to this idea about the way we look at non 0:22:08.680 --> 0:22:12.000 human animals and tend to to judge their parenting. I mean, 0:22:12.040 --> 0:22:14.159 that's inherently what I was doing when I think it's 0:22:14.200 --> 0:22:17.520 funny just watching the mother crabs chuck their eggs off 0:22:17.520 --> 0:22:22.639 a cliff. But it's like it's hilarious watching a crab 0:22:22.760 --> 0:22:25.320