1 00:00:03,040 --> 00:00:05,360 Speaker 1: Welcome to Stuff to Blow Your Mind production of My 2 00:00:05,480 --> 00:00:15,080 Speaker 1: Heart Radio. Hey, welcome to Stuff to Blow Your Mind. 3 00:00:15,240 --> 00:00:17,959 Speaker 1: My name is Robert Manam and I'm Joe McCormick, and 4 00:00:17,960 --> 00:00:20,480 Speaker 1: we're back with part two of our series on the 5 00:00:20,520 --> 00:00:24,360 Speaker 1: reptiles of the Galapagos Islands. Now, in the previous episode, 6 00:00:24,400 --> 00:00:28,440 Speaker 1: we focused mainly on the marine iguana, or as as 7 00:00:28,480 --> 00:00:31,800 Speaker 1: they were often referred to early on those hideous creatures, 8 00:00:32,240 --> 00:00:37,480 Speaker 1: those stupid, awful, sluggish lizards. We we mounted a defense 9 00:00:37,760 --> 00:00:40,800 Speaker 1: of the marine iguana. But today we are here to 10 00:00:40,880 --> 00:00:44,720 Speaker 1: talk about the Galapagos tortoise. And I wanted to kick 11 00:00:44,760 --> 00:00:49,519 Speaker 1: things off by reading a passage from Charles Darwin in 12 00:00:49,640 --> 00:00:52,080 Speaker 1: the Voyage of the Beagle. Darwin, of course, was not 13 00:00:52,120 --> 00:00:54,360 Speaker 1: just a great scientist, but a really wonderful writer. And 14 00:00:54,360 --> 00:00:57,160 Speaker 1: I think this this will help set the scene. So 15 00:00:57,560 --> 00:01:01,080 Speaker 1: are you ready to hear about Darwin's first vision of 16 00:01:01,120 --> 00:01:05,479 Speaker 1: San Cristobul Island, then then what they called Chatham Island. Yeah, 17 00:01:05,600 --> 00:01:08,800 Speaker 1: let's let's hear from from old Charles. And this is 18 00:01:08,840 --> 00:01:11,920 Speaker 1: part of a narrative of when he slept ashore one 19 00:01:12,040 --> 00:01:15,720 Speaker 1: night on the island, So off the boat, Darwin writes 20 00:01:16,200 --> 00:01:18,920 Speaker 1: the entire surface of this part of the island seems 21 00:01:18,920 --> 00:01:23,440 Speaker 1: to have been permeated like a sieve by the subterranean vapors. 22 00:01:24,000 --> 00:01:27,760 Speaker 1: Here and there the lava, whilst soft, has been blown 23 00:01:27,800 --> 00:01:31,039 Speaker 1: into great bubbles, and in other parts the tops of 24 00:01:31,160 --> 00:01:35,759 Speaker 1: cavern similarly formed of fallen in, leaving circular pits with 25 00:01:35,840 --> 00:01:39,800 Speaker 1: steep sides from the regular form of the many craters. 26 00:01:39,840 --> 00:01:43,720 Speaker 1: They gave to the country an artificial appearance which vividly 27 00:01:43,840 --> 00:01:47,520 Speaker 1: reminded me of those parts of Staffordshire where the great 28 00:01:47,560 --> 00:01:51,640 Speaker 1: iron foundries are most numerous. The day was growing hot, 29 00:01:51,800 --> 00:01:54,600 Speaker 1: and the scrambling over the rough surface and through the 30 00:01:54,640 --> 00:01:58,720 Speaker 1: intricate thickets was very fatiguing, but I was well repaid 31 00:01:58,720 --> 00:02:03,360 Speaker 1: by the strange clopian scene. As I was walking along, 32 00:02:03,440 --> 00:02:07,280 Speaker 1: I met two large tortoises, each of which must have 33 00:02:07,320 --> 00:02:10,760 Speaker 1: weighed at least two hundred pounds. One was eating a 34 00:02:10,800 --> 00:02:13,919 Speaker 1: piece of cactus, and as I approached it stared at 35 00:02:13,960 --> 00:02:17,760 Speaker 1: me and slowly walked away. The other gave a deep 36 00:02:18,160 --> 00:02:23,239 Speaker 1: hiss and drew in its head. These huge reptiles, surrounded 37 00:02:23,240 --> 00:02:27,720 Speaker 1: by the black lava, the leafless shrubs and large cacti, 38 00:02:27,880 --> 00:02:32,320 Speaker 1: seemed to my fancy like some Antediluvian animals. The few 39 00:02:32,480 --> 00:02:35,840 Speaker 1: dull colored birds cared no more for me than they 40 00:02:35,840 --> 00:02:40,120 Speaker 1: did for the great tortoises. So Darwin transported to a 41 00:02:40,160 --> 00:02:44,200 Speaker 1: time from before Noah's flood by the vision of these bizarre, 42 00:02:44,360 --> 00:02:49,960 Speaker 1: gigantic tortoises crawling around on the on the lava. Yes, 43 00:02:50,400 --> 00:02:53,799 Speaker 1: this is the great SCENEY paints here and um and yeah. 44 00:02:53,960 --> 00:02:55,880 Speaker 1: As I mentioned in the first episode, I was. I 45 00:02:55,919 --> 00:02:58,639 Speaker 1: was fortunate enough to get to travel to the Galapico 46 00:02:58,760 --> 00:03:01,480 Speaker 1: Highlands uh to to a couple of months ago in 47 00:03:01,520 --> 00:03:03,679 Speaker 1: San Cristobo Island was one of the islands that I 48 00:03:03,720 --> 00:03:06,799 Speaker 1: got to visit, and this was pretty much the the 49 00:03:06,800 --> 00:03:09,600 Speaker 1: the experience I had with my family walking through one 50 00:03:09,639 --> 00:03:12,680 Speaker 1: of the uh the areas they had set aside for 51 00:03:13,000 --> 00:03:18,480 Speaker 1: these magnificent tortoises. They're just they just they walk around 52 00:03:19,440 --> 00:03:22,080 Speaker 1: as if yeah, as if you you don't matter, unless 53 00:03:22,080 --> 00:03:24,600 Speaker 1: you get a little too close for their liking, in 54 00:03:24,639 --> 00:03:27,920 Speaker 1: which case they'll often be this hiss and this retraction 55 00:03:27,960 --> 00:03:29,760 Speaker 1: of their head. I mean, their heads don't retract in 56 00:03:29,760 --> 00:03:31,680 Speaker 1: the same way that say, a box turtle does, but 57 00:03:31,720 --> 00:03:33,720 Speaker 1: they're able to sort of pull their head in a bit. 58 00:03:34,280 --> 00:03:37,680 Speaker 1: But that the hissing that Darwin is describing here. It 59 00:03:37,760 --> 00:03:40,280 Speaker 1: does have a very i don't know, neumatic kind of 60 00:03:40,360 --> 00:03:42,480 Speaker 1: quality to it. It feels it sounds like some sort 61 00:03:42,480 --> 00:03:46,080 Speaker 1: of machinery um. And indeed, that's that's kind of more 62 00:03:46,120 --> 00:03:48,280 Speaker 1: what it is, as opposed to like the hiss you 63 00:03:48,360 --> 00:03:52,240 Speaker 1: might hear from a house cat or something. And one 64 00:03:52,240 --> 00:03:55,280 Speaker 1: of the things that I kept thinking about while encountering 65 00:03:55,320 --> 00:04:00,320 Speaker 1: them is that they already move with this kind of hookey, 66 00:04:00,400 --> 00:04:05,080 Speaker 1: jerky kind of um locomotion. They already move like they 67 00:04:05,120 --> 00:04:11,200 Speaker 1: are elaborate mechanical creatures created for practical effects for a 68 00:04:11,320 --> 00:04:15,160 Speaker 1: nineteen nineties UH science fiction feature. And then they also 69 00:04:15,240 --> 00:04:19,000 Speaker 1: make this hissing sound to move part of their anatomy. 70 00:04:19,040 --> 00:04:22,040 Speaker 1: So it almost creates this feeling of am I really 71 00:04:22,080 --> 00:04:27,320 Speaker 1: seeing real animals or is this an elaborate hoax these animatronics? Yeah, yeah, yeah, 72 00:04:27,360 --> 00:04:30,000 Speaker 1: they they feel almost like animatronics, But of course they're 73 00:04:30,160 --> 00:04:32,479 Speaker 1: they're they're they're quite alive, and they're quite but that's 74 00:04:32,520 --> 00:04:34,960 Speaker 1: that's part of their strangeness. And they just the awe 75 00:04:34,960 --> 00:04:39,760 Speaker 1: of watching these giant creatures walk around, slowly, eat and 76 00:04:39,760 --> 00:04:44,920 Speaker 1: occasionally have some startling interactions. Now I'm I'm greatly envious 77 00:04:44,960 --> 00:04:48,080 Speaker 1: of the opportunity you got to see these animals in person. 78 00:04:48,160 --> 00:04:51,359 Speaker 1: But I trust that you did not do what Darwin 79 00:04:51,480 --> 00:04:55,120 Speaker 1: did upon encountering these beasts and try to ride them. 80 00:04:55,400 --> 00:05:00,160 Speaker 1: Absolutely not know they're the only time the time we 81 00:05:00,160 --> 00:05:03,480 Speaker 1: were forced to get uncomfortably close with one of these 82 00:05:03,520 --> 00:05:05,520 Speaker 1: situations of the area that we were walking through had 83 00:05:05,520 --> 00:05:08,080 Speaker 1: a path, and you're supposed to stay on the path 84 00:05:08,440 --> 00:05:11,240 Speaker 1: and keep your distance from the tortoises. Sometimes, though, the 85 00:05:11,240 --> 00:05:14,080 Speaker 1: tortoises will just get on the path and you have 86 00:05:14,160 --> 00:05:17,560 Speaker 1: to find your way around them, and uh, they don't 87 00:05:17,560 --> 00:05:21,440 Speaker 1: necessarily like that, but no, we we kept our distance, um, 88 00:05:21,520 --> 00:05:23,520 Speaker 1: and and you want to keep your distance because yeah, 89 00:05:23,560 --> 00:05:26,040 Speaker 1: if you get a little too close, they're gonna stop 90 00:05:26,360 --> 00:05:28,880 Speaker 1: interacting with their environment for a little bit. And if 91 00:05:28,920 --> 00:05:30,480 Speaker 1: you don't want to watch that, you want to watch 92 00:05:30,520 --> 00:05:33,960 Speaker 1: them eat and and rampage around and uh, you know 93 00:05:34,000 --> 00:05:39,040 Speaker 1: occasionally have these fabulous stare downs between two males which 94 00:05:39,200 --> 00:05:40,839 Speaker 1: I don't know, we may we may describe this later, 95 00:05:40,920 --> 00:05:43,520 Speaker 1: So maybe I shouldn't get into that just yet. Yeah, yeah, 96 00:05:43,520 --> 00:05:46,120 Speaker 1: we can talk about the mock fights later on. So 97 00:05:46,600 --> 00:05:49,839 Speaker 1: the Galapa ghost tortoise is I think you would say 98 00:05:50,240 --> 00:05:55,760 Speaker 1: originally the dominant land herbivore of the Galapagos Islands, which 99 00:05:55,839 --> 00:05:59,279 Speaker 1: makes them kind of unique because there's pretty much nowhere, 100 00:05:59,520 --> 00:06:03,000 Speaker 1: nowhere else us on Earth now where the dominant land 101 00:06:03,040 --> 00:06:07,440 Speaker 1: herbivore is a reptile. Uh So, these are very unique 102 00:06:07,440 --> 00:06:11,120 Speaker 1: and beautiful creatures, and the Galapos tortoise stands out so 103 00:06:11,200 --> 00:06:14,919 Speaker 1: much among the endemic fauna that it's actually the origin 104 00:06:15,160 --> 00:06:18,160 Speaker 1: of the archipelago's name in one way or another. There's 105 00:06:18,200 --> 00:06:21,000 Speaker 1: a little bit of nitpicking on that, but basically it 106 00:06:21,040 --> 00:06:25,240 Speaker 1: goes like this. By the fifteen seventies, these islands had 107 00:06:25,240 --> 00:06:28,600 Speaker 1: already appeared on at least a couple of European maps. 108 00:06:28,760 --> 00:06:32,600 Speaker 1: The one I saw named was by a Flemish cartographer 109 00:06:32,680 --> 00:06:37,040 Speaker 1: named Abraham or Talias, and it named the islands Insula 110 00:06:37,240 --> 00:06:41,320 Speaker 1: de los Galapagos or meaning Islands of the Tortoises. Now, 111 00:06:41,480 --> 00:06:46,200 Speaker 1: the nitpicking about the terminology I've read is what exactly 112 00:06:46,240 --> 00:06:50,920 Speaker 1: the word galapago or Galapagos originally meant. According to a 113 00:06:50,960 --> 00:06:54,039 Speaker 1: book that I'm going to reference multiple times in this episode, 114 00:06:54,440 --> 00:06:58,600 Speaker 1: Galapagos and Natural History, second Edition by John Creature and 115 00:06:59,240 --> 00:07:02,680 Speaker 1: Kevin Loft Lend from Princeton University Press that editions out 116 00:07:02,720 --> 00:07:06,320 Speaker 1: just two. They write that the origin of the name 117 00:07:06,320 --> 00:07:10,040 Speaker 1: of the islands is an old Spanish word, galapago, which 118 00:07:10,160 --> 00:07:13,840 Speaker 1: was a name for a specific type of saddle. So 119 00:07:13,920 --> 00:07:15,800 Speaker 1: there's like, you know, a saddle you'd use on a horse. 120 00:07:15,840 --> 00:07:18,880 Speaker 1: I guess that has a kind of upturned front. That 121 00:07:19,040 --> 00:07:22,720 Speaker 1: was a galapago. And some, but not all, of the 122 00:07:22,720 --> 00:07:27,760 Speaker 1: Galapagos tortoises have saddle shaped shells. Others have a more 123 00:07:27,800 --> 00:07:30,640 Speaker 1: straightforward dome. And we can talk about the evolutionary reasons 124 00:07:30,680 --> 00:07:35,000 Speaker 1: for those differences later on. But when Tamas de Brelonga 125 00:07:35,360 --> 00:07:37,880 Speaker 1: landed on the islands in fifteen thirty five, a story 126 00:07:37,880 --> 00:07:40,640 Speaker 1: we talked about in the previous episode. After this, he 127 00:07:40,720 --> 00:07:43,800 Speaker 1: wrote a letter to the king in which he observed 128 00:07:44,440 --> 00:07:47,679 Speaker 1: describing the animals of the island. He observed Muccio's lobos 129 00:07:47,760 --> 00:07:53,040 Speaker 1: marinos meaning many sea lions, tortugas meaning sea turtles, iguanas, 130 00:07:53,080 --> 00:07:57,160 Speaker 1: and Galapagos, and the author's right that this is probably 131 00:07:57,200 --> 00:08:00,800 Speaker 1: a reference to the tortoises and their saddle shaped shells 132 00:08:00,920 --> 00:08:04,520 Speaker 1: rather than to literal saddles being on the island. This 133 00:08:04,560 --> 00:08:07,640 Speaker 1: is a solid observation that thankfully still holds true today 134 00:08:07,720 --> 00:08:14,560 Speaker 1: Muccio's lobos Marinosto is iguanas and uh and and tortoises. Yes, yeah, 135 00:08:14,680 --> 00:08:18,000 Speaker 1: the seed line, I mean the Muccio lobos marinos. Uh. 136 00:08:18,360 --> 00:08:20,520 Speaker 1: That was probably the most astounding of all when you're 137 00:08:20,560 --> 00:08:24,880 Speaker 1: near the coast, because they're everywhere, and they'll see sometimes laying. 138 00:08:25,160 --> 00:08:27,240 Speaker 1: They'll be like a male that's come up and he's 139 00:08:27,280 --> 00:08:31,040 Speaker 1: like laying in the street, or they they love park benches. 140 00:08:31,600 --> 00:08:33,320 Speaker 1: There are a lot of fun to wide well. The 141 00:08:33,320 --> 00:08:35,480 Speaker 1: difference in the Spanish name. I guess if it's lobo 142 00:08:35,600 --> 00:08:38,439 Speaker 1: marino that would mean sea wolf, not sea lion, right, 143 00:08:38,480 --> 00:08:42,600 Speaker 1: But that that heightens the kind of implicit comedy of 144 00:08:42,760 --> 00:08:45,360 Speaker 1: naming these animals after what you would think of as 145 00:08:45,360 --> 00:08:48,880 Speaker 1: a more actively voracious land predator, whereas you know, I 146 00:08:48,880 --> 00:08:51,920 Speaker 1: guess when they're on the land, they're not quite so threatening. 147 00:08:52,040 --> 00:08:54,439 Speaker 1: Is maybe a wolf for a lion would seem yeah, 148 00:08:54,520 --> 00:08:56,040 Speaker 1: I mean, well, on one hand, yeah, you have some 149 00:08:56,080 --> 00:08:58,800 Speaker 1: of the little tiny islands there as least one that's 150 00:08:58,880 --> 00:09:01,480 Speaker 1: named for the wolf for the lobos, and of course 151 00:09:01,480 --> 00:09:04,000 Speaker 1: that's why, because the sea lions are hanging out there, 152 00:09:04,040 --> 00:09:06,920 Speaker 1: and yeah, on the on the on the beach, they're 153 00:09:06,960 --> 00:09:10,560 Speaker 1: they're often quite docile, and you see people getting way 154 00:09:10,640 --> 00:09:13,280 Speaker 1: too close to them in some cases. But the big males, 155 00:09:13,320 --> 00:09:16,640 Speaker 1: of course are very territorial about hanging onto their bit 156 00:09:16,679 --> 00:09:20,200 Speaker 1: of property and their um and their females. Uh you know, 157 00:09:20,240 --> 00:09:23,240 Speaker 1: they're their their beach real estate, and so there of 158 00:09:23,280 --> 00:09:28,679 Speaker 1: course always they're continuously loudly um sending the alarm and 159 00:09:28,720 --> 00:09:31,520 Speaker 1: occasionally chasing off other males. So there's there's a lot 160 00:09:31,559 --> 00:09:33,880 Speaker 1: of drama if you just sit back and watch that 161 00:09:33,960 --> 00:09:37,120 Speaker 1: the sea lions, and I imagine that listeners from other 162 00:09:37,120 --> 00:09:40,199 Speaker 1: parts of the world can attest to this as well. Yes, yes, 163 00:09:40,320 --> 00:09:44,120 Speaker 1: keep your distance, folks, I mean, observe, but but there's 164 00:09:44,160 --> 00:09:46,960 Speaker 1: no reason to get in the sea lions space, though 165 00:09:47,040 --> 00:09:49,160 Speaker 1: sometimes in my experience of sea lion will come for 166 00:09:49,240 --> 00:09:52,600 Speaker 1: your space. I was just seated away from sea lions 167 00:09:53,080 --> 00:09:55,920 Speaker 1: and then here comes this female and she's just howling 168 00:09:55,920 --> 00:09:58,560 Speaker 1: about something and insists on taking my spot on a 169 00:09:58,600 --> 00:10:00,679 Speaker 1: log and I'm like this, you're the chairs. And then 170 00:10:00,720 --> 00:10:02,120 Speaker 1: she just hangs out on the log for a few 171 00:10:02,160 --> 00:10:05,240 Speaker 1: minutes and then leaves it. I don't know. So you're 172 00:10:05,240 --> 00:10:08,920 Speaker 1: just trying to make a point. So if you have 173 00:10:09,040 --> 00:10:12,880 Speaker 1: never seen the Galapagos tortoises before. You can easily find 174 00:10:12,880 --> 00:10:16,480 Speaker 1: lots of pictures of them, but to briefly describe the adults, 175 00:10:16,520 --> 00:10:20,320 Speaker 1: there are many different species scattered across the different islands. 176 00:10:20,360 --> 00:10:22,200 Speaker 1: Maybe we can get into the exact numbers on that 177 00:10:22,240 --> 00:10:24,720 Speaker 1: in a bit, but generally what they all have in 178 00:10:24,760 --> 00:10:28,439 Speaker 1: common is that they're very large. They have large shells, 179 00:10:28,880 --> 00:10:32,480 Speaker 1: some species with rounded dome tops, others with the saddle 180 00:10:32,559 --> 00:10:36,120 Speaker 1: shape that Burlonga probably observed, which are typically turned up 181 00:10:36,160 --> 00:10:38,640 Speaker 1: in the front to have a kind of big notch 182 00:10:39,120 --> 00:10:44,400 Speaker 1: above the animal's head and neck. They have long, dry, 183 00:10:44,400 --> 00:10:48,920 Speaker 1: wrinkly necks which are surprisingly slim, almost I dare say 184 00:10:48,960 --> 00:10:53,880 Speaker 1: snake like in a way. They have blunt, round snouts 185 00:10:53,960 --> 00:10:58,200 Speaker 1: and a beak like mouth with no teeth, and everywhere 186 00:10:58,280 --> 00:11:01,199 Speaker 1: you can see their their skin. In between the shell 187 00:11:01,360 --> 00:11:05,199 Speaker 1: parts there is typically a lot of leathery, wrinkly flesh, 188 00:11:05,240 --> 00:11:09,240 Speaker 1: which just makes them look like old people. Yeah, they 189 00:11:09,720 --> 00:11:12,680 Speaker 1: have this kind of appearance of of a cute, shriveled 190 00:11:12,679 --> 00:11:16,000 Speaker 1: old person. Vase. Uh, They're they're very They're very sweet 191 00:11:16,120 --> 00:11:19,040 Speaker 1: too to look at. Um. It's it's it's kind of 192 00:11:19,080 --> 00:11:23,360 Speaker 1: hard to to not anthropomorphize them as such. Even in 193 00:11:23,360 --> 00:11:25,880 Speaker 1: and that of course, can become complicated when you start 194 00:11:25,880 --> 00:11:29,240 Speaker 1: considering like the full range of their um, of their 195 00:11:29,280 --> 00:11:32,400 Speaker 1: lifestyle and the way that they they live and reproduce 196 00:11:32,480 --> 00:11:36,520 Speaker 1: and so forth. Uh. It never pays to anthropomorphizes creatures 197 00:11:36,559 --> 00:11:40,360 Speaker 1: too much. Yeah. Now, one thing many of us today 198 00:11:40,480 --> 00:11:42,760 Speaker 1: might not appreciate, even if you go to the Galapagos 199 00:11:42,840 --> 00:11:45,560 Speaker 1: today or if you see you know, good nature documentary 200 00:11:45,600 --> 00:11:50,600 Speaker 1: footage from there, is how many tortoises there were when 201 00:11:50,600 --> 00:11:54,479 Speaker 1: people first arrived, before the animals had any natural predators 202 00:11:54,559 --> 00:11:58,760 Speaker 1: other than the threat post hatchlings by the Galapagos hawk. Uh, 203 00:11:58,840 --> 00:12:03,040 Speaker 1: this place was swarming with tortoises. And to try to 204 00:12:03,080 --> 00:12:06,200 Speaker 1: get a picture of that, uh, I wanted to cite 205 00:12:06,240 --> 00:12:09,880 Speaker 1: some some basically math work that Creature in Laughlin do 206 00:12:09,960 --> 00:12:14,080 Speaker 1: in their book. So they're talking about the reproductive rates 207 00:12:14,080 --> 00:12:17,640 Speaker 1: of these tortoises. So they say, if if a female 208 00:12:17,800 --> 00:12:22,720 Speaker 1: tortoise has more than two young that survive into adulthood, 209 00:12:22,960 --> 00:12:26,680 Speaker 1: the tortoise population will grow, so she has replaced both 210 00:12:26,720 --> 00:12:29,320 Speaker 1: her and her mate, and if she has more than one, 211 00:12:29,360 --> 00:12:33,640 Speaker 1: the population will grow. And they say, now, consider that 212 00:12:33,720 --> 00:12:37,720 Speaker 1: a female tortoise may conservatively lay five to tin eggs 213 00:12:37,800 --> 00:12:43,080 Speaker 1: annually for perhaps eighty years or more. So just uh, 214 00:12:43,520 --> 00:12:47,000 Speaker 1: for a very conservative estimate, they say, Okay, imagine she 215 00:12:47,080 --> 00:12:50,560 Speaker 1: averages one annual clutch and there's just three eggs in it. 216 00:12:50,600 --> 00:12:52,800 Speaker 1: That's kind of a small estimate. But there's just three 217 00:12:52,840 --> 00:12:55,600 Speaker 1: eggs per clutch. That's more than two hundred eggs in 218 00:12:55,640 --> 00:13:00,320 Speaker 1: a single adult female tortoises lifetime. Uh, they say, realist stically, 219 00:13:00,400 --> 00:13:02,960 Speaker 1: the numbers probably a multiple of that. So they're gonna 220 00:13:03,000 --> 00:13:06,920 Speaker 1: have a lot of young and there before humans arrive 221 00:13:07,040 --> 00:13:10,240 Speaker 1: and bring their invasive species with them, before they bring 222 00:13:10,320 --> 00:13:14,240 Speaker 1: dogs and pigs and stuff. There is not significant predation 223 00:13:14,440 --> 00:13:17,679 Speaker 1: at any life cycle part of the life cycle of 224 00:13:17,720 --> 00:13:21,280 Speaker 1: a tortoise. Uh. There's some minor predation by like hawks 225 00:13:21,400 --> 00:13:24,480 Speaker 1: of the babies, but most of them are going to 226 00:13:24,520 --> 00:13:29,000 Speaker 1: grow and become reproducing adults. Yeah, it's pretty amazing. Amazing. 227 00:13:29,040 --> 00:13:32,120 Speaker 1: I asked one of the guides about, you know, how 228 00:13:32,120 --> 00:13:35,040 Speaker 1: long are the females reproductive? Because you see some very 229 00:13:35,880 --> 00:13:37,600 Speaker 1: he was pointed that my guide here was pointing out 230 00:13:37,600 --> 00:13:40,360 Speaker 1: the various really old tortoises. But because you can sort 231 00:13:40,360 --> 00:13:42,240 Speaker 1: of tell by looking at the shells the way that 232 00:13:42,760 --> 00:13:44,880 Speaker 1: um the line, like for a while, you can sort 233 00:13:44,920 --> 00:13:46,800 Speaker 1: of it's not like you can count the rings exactly, 234 00:13:46,840 --> 00:13:50,240 Speaker 1: but you can sort of see the rings in the 235 00:13:51,200 --> 00:13:53,480 Speaker 1: patterns on their shell. But eventually there's kind of like 236 00:13:53,480 --> 00:13:55,520 Speaker 1: a smoothing out that occurs, and those are the really 237 00:13:55,520 --> 00:13:58,720 Speaker 1: old ones. Um And and the guy was like, yeah, 238 00:13:58,760 --> 00:14:02,199 Speaker 1: we're we're not entirely sure, but it seems like they're 239 00:14:02,240 --> 00:14:06,680 Speaker 1: reproductively active for pretty much most of their lives, which 240 00:14:06,679 --> 00:14:18,400 Speaker 1: is the astounding thank thank Yeah, it's it's amazing. And 241 00:14:18,440 --> 00:14:21,080 Speaker 1: so the authors of this book end up concluding that 242 00:14:21,840 --> 00:14:25,360 Speaker 1: before humans arrived and and brought these invasive predators with 243 00:14:25,400 --> 00:14:28,800 Speaker 1: them and started harvesting the tortoises themselves, which is a 244 00:14:28,800 --> 00:14:31,840 Speaker 1: sad fact we'll talk about in a moment um, the 245 00:14:31,880 --> 00:14:37,440 Speaker 1: tortoises were just just profuse. They were everywhere. They say, 246 00:14:37,480 --> 00:14:40,240 Speaker 1: there's a conservative estimate of a total population of two 247 00:14:40,280 --> 00:14:43,520 Speaker 1: hundred and fifty thousand tortoises just on this small group 248 00:14:43,520 --> 00:14:47,880 Speaker 1: of islands. But of course today, um, all of these 249 00:14:47,880 --> 00:14:52,320 Speaker 1: tortoise populations are at least vulnerable, and some are up 250 00:14:52,320 --> 00:14:56,680 Speaker 1: to critically endangered. And and that's after a significant bounce 251 00:14:56,720 --> 00:15:00,000 Speaker 1: back in some cases for you know, after conservation effort, 252 00:15:00,000 --> 00:15:04,280 Speaker 1: it's kicked in. So what happened to these tortoises. Well, 253 00:15:04,640 --> 00:15:08,360 Speaker 1: one thing that happened is uh is something Darwin talks 254 00:15:08,360 --> 00:15:11,160 Speaker 1: about in his Passage and Voyage of the Beagle. Before 255 00:15:11,200 --> 00:15:14,400 Speaker 1: he even really gets to ecological observations about the tortoises, 256 00:15:14,640 --> 00:15:19,560 Speaker 1: he writes at length about people eating them. So, in 257 00:15:19,640 --> 00:15:23,440 Speaker 1: describing the small human colony on what was then Charles 258 00:15:23,480 --> 00:15:27,560 Speaker 1: Island what today is called Floriana Island, so Darwin writes, 259 00:15:28,080 --> 00:15:31,160 Speaker 1: in the woods there are many wild pigs and goats. 260 00:15:31,520 --> 00:15:33,680 Speaker 1: Now remember those are not native to the islands, but 261 00:15:33,800 --> 00:15:37,640 Speaker 1: introduced by humans. Darwin goes on, But the staple article 262 00:15:37,680 --> 00:15:41,720 Speaker 1: of animal food is supplied by the tortoises. Their numbers 263 00:15:41,720 --> 00:15:44,120 Speaker 1: have of course been greatly reduced in this island, but 264 00:15:44,160 --> 00:15:46,960 Speaker 1: the people yet count on two days hunting, giving them 265 00:15:47,000 --> 00:15:49,680 Speaker 1: food for the rest of the week. It is said 266 00:15:49,680 --> 00:15:53,160 Speaker 1: that formerly single vessels have taken away as many as 267 00:15:53,240 --> 00:15:56,400 Speaker 1: seven hundred, and that the ship's company of a frigate 268 00:15:56,560 --> 00:16:00,800 Speaker 1: some years since brought down in one day two tortoises 269 00:16:00,840 --> 00:16:03,880 Speaker 1: to the beach. And this brings us to a very 270 00:16:03,920 --> 00:16:06,480 Speaker 1: sad fact about the human use of tortoises. Here that 271 00:16:06,720 --> 00:16:09,760 Speaker 1: tortoises were of course very good meat sources for sailing 272 00:16:09,840 --> 00:16:13,440 Speaker 1: vessels um, but this was especially due to the fact 273 00:16:13,560 --> 00:16:17,760 Speaker 1: that because turtles have a very slow metabolism, and they 274 00:16:17,800 --> 00:16:21,520 Speaker 1: could be loaded into the ship alive and then would 275 00:16:21,560 --> 00:16:25,160 Speaker 1: survive for an extremely long time without food or water 276 00:16:25,400 --> 00:16:28,480 Speaker 1: in the hold. And it's important to remember that, of course, 277 00:16:28,480 --> 00:16:31,520 Speaker 1: ships at the time didn't have refrigerators or freezers or 278 00:16:31,560 --> 00:16:35,760 Speaker 1: other sophisticated food preservation techniques beyond things like you know, 279 00:16:35,800 --> 00:16:39,640 Speaker 1: the nuclear options salting. Yeah. Yeah, So this is this 280 00:16:39,720 --> 00:16:42,680 Speaker 1: is quite sad to picture because on one hand, it's 281 00:16:43,120 --> 00:16:46,080 Speaker 1: it's not like these tortoises were wandering around on deck. No, 282 00:16:46,200 --> 00:16:49,200 Speaker 1: they they were stuffed below i think generally upside down 283 00:16:49,440 --> 00:16:54,960 Speaker 1: and just stored away as living casks of food because 284 00:16:55,000 --> 00:16:57,440 Speaker 1: they could live for up to a year without food 285 00:16:57,520 --> 00:16:59,880 Speaker 1: or water, which is just crazy to think about, but 286 00:17:00,040 --> 00:17:04,600 Speaker 1: also just unimaginally cruel to imagine them down there. And 287 00:17:04,800 --> 00:17:07,200 Speaker 1: on top of this, one of the other troublesome things 288 00:17:07,200 --> 00:17:11,359 Speaker 1: about this for the tortoises is that the sailors would 289 00:17:11,400 --> 00:17:13,840 Speaker 1: tend to grab the tortoises they could easily carry back 290 00:17:13,880 --> 00:17:16,480 Speaker 1: to the ship, which meant that they tended to focus 291 00:17:16,560 --> 00:17:19,239 Speaker 1: on the smaller tortoises and leave the bigger ones. This 292 00:17:19,320 --> 00:17:23,199 Speaker 1: meant that they were favoring female tortoises over male tortoises, 293 00:17:23,480 --> 00:17:26,040 Speaker 1: and I guess to a certain extent also younger male tortoises, 294 00:17:26,040 --> 00:17:30,399 Speaker 1: but certainly skewing more towards female tortoises, thus destabilizing the 295 00:17:30,440 --> 00:17:32,760 Speaker 1: species even more than if they had managed more of 296 00:17:32,760 --> 00:17:37,000 Speaker 1: a fifty fifty split between the tortoise genders. Yeah. So, 297 00:17:37,080 --> 00:17:40,240 Speaker 1: unfortunately a lot of tortoises were removed from the islands 298 00:17:40,280 --> 00:17:44,920 Speaker 1: that way, but also they just remained a a live 299 00:17:45,040 --> 00:17:49,080 Speaker 1: meat source for hunting by the locals. And Darwin tells 300 00:17:49,160 --> 00:17:52,760 Speaker 1: many interesting stories about this. Uh. For example, he writes 301 00:17:52,800 --> 00:17:55,919 Speaker 1: about a time that he went up to one of 302 00:17:55,960 --> 00:17:58,520 Speaker 1: the highland regions of one of the islands, and he 303 00:17:58,600 --> 00:18:00,920 Speaker 1: hung out in a hovel that had been built by 304 00:18:01,119 --> 00:18:03,960 Speaker 1: two men there who were who spent their their time 305 00:18:04,040 --> 00:18:07,800 Speaker 1: hunting tortoises. And so he visits these guys and he 306 00:18:07,840 --> 00:18:10,880 Speaker 1: sleeps there in the hovel one night. Um and what 307 00:18:10,920 --> 00:18:14,160 Speaker 1: did he eat while he was there, Well, exclusively tortoise meat. 308 00:18:14,200 --> 00:18:17,520 Speaker 1: That was the entire menu, about which he says, quote 309 00:18:17,640 --> 00:18:22,080 Speaker 1: the breastplate roasted as the gauchos do carne conquero, which 310 00:18:22,320 --> 00:18:25,919 Speaker 1: I think means meat with leather with the flesh on. 311 00:18:26,000 --> 00:18:29,200 Speaker 1: It is very good, and the young tortoises make excellent soup, 312 00:18:29,359 --> 00:18:33,040 Speaker 1: but otherwise the meat, to my taste, is indifferent. Well, 313 00:18:33,040 --> 00:18:36,560 Speaker 1: there you go. Also taking harvesting the young tortoises. That's 314 00:18:36,560 --> 00:18:40,160 Speaker 1: great as well, but they apparently these these the adult tortoises, 315 00:18:40,160 --> 00:18:43,080 Speaker 1: are an amazing food source because of their immense size, 316 00:18:43,119 --> 00:18:46,440 Speaker 1: and Darwin recounts the story told to him by a Mr. Lawson, 317 00:18:46,960 --> 00:18:50,000 Speaker 1: who is an Englishman who was vice governor of the 318 00:18:50,119 --> 00:18:54,600 Speaker 1: Charles Island Colony, saying that some tortoises, when caught, required 319 00:18:54,680 --> 00:18:57,000 Speaker 1: six to eight men just to lift them off the 320 00:18:57,000 --> 00:18:59,800 Speaker 1: ground and would provide up to two hundred pounds of 321 00:18:59,840 --> 00:19:04,440 Speaker 1: me eat. Darwin also later describes a strange operation performed 322 00:19:04,480 --> 00:19:06,440 Speaker 1: by the hunters. He says that you know they didn't 323 00:19:06,480 --> 00:19:11,119 Speaker 1: always kill a tortoise. He said that while the tortoises 324 00:19:11,119 --> 00:19:14,639 Speaker 1: meat is used both fresh and salted. Uh, the tortoises 325 00:19:14,640 --> 00:19:18,760 Speaker 1: are also important for providing oil. That's right, reptile lard 326 00:19:19,000 --> 00:19:21,520 Speaker 1: and oil that I think could be used for for 327 00:19:21,520 --> 00:19:26,120 Speaker 1: food purposes. But also for just like like like lamp purposes. 328 00:19:26,160 --> 00:19:29,399 Speaker 1: I believe. Yeah, it's it's said that in the old days, 329 00:19:29,440 --> 00:19:31,840 Speaker 1: the larger towns of the Galapagos would have their streets 330 00:19:31,840 --> 00:19:34,760 Speaker 1: would have been lit with tortoise oil. Bizarre though, I 331 00:19:34,760 --> 00:19:38,119 Speaker 1: guess we're more familiar with that from like whale oil 332 00:19:38,200 --> 00:19:41,160 Speaker 1: and stuff. Um. But yeah, So if if a tortoise 333 00:19:41,240 --> 00:19:44,040 Speaker 1: will not provide enough oil, it is apparently not worth 334 00:19:44,119 --> 00:19:46,919 Speaker 1: killing to the hunters. So Darwin writes, quote, when a 335 00:19:46,960 --> 00:19:49,399 Speaker 1: tortoise is caught, the man makes a slit in the 336 00:19:49,440 --> 00:19:52,120 Speaker 1: skin near its tail so as to see inside its 337 00:19:52,200 --> 00:19:55,640 Speaker 1: body whether the fat under the dorsal plate is thick. 338 00:19:56,000 --> 00:19:58,480 Speaker 1: If it's not, the animal is liberated, and it is 339 00:19:58,480 --> 00:20:02,080 Speaker 1: said to recover soon from this strange operation. In order 340 00:20:02,080 --> 00:20:04,920 Speaker 1: to secure the tortoise, it is not sufficient to turn 341 00:20:05,000 --> 00:20:07,639 Speaker 1: them like a turtle, for they are often able to 342 00:20:07,680 --> 00:20:10,320 Speaker 1: get on their legs again. And I think this is 343 00:20:10,359 --> 00:20:12,920 Speaker 1: something that will come up later, because there are some 344 00:20:12,960 --> 00:20:16,000 Speaker 1: situations where these tortoises often do end up flipped on 345 00:20:16,040 --> 00:20:19,159 Speaker 1: their backs, even under natural circumstances, and they need to 346 00:20:19,160 --> 00:20:21,680 Speaker 1: be able to flip back over and get back to business. 347 00:20:22,359 --> 00:20:24,760 Speaker 1: I did not get to see that happen. Thankfully, I 348 00:20:24,760 --> 00:20:27,600 Speaker 1: don't want to see a tortoise in distress. No, we're 349 00:20:27,640 --> 00:20:30,000 Speaker 1: not going to ask you the quiz from the blade 350 00:20:30,040 --> 00:20:33,520 Speaker 1: runner test. So what do these tortoises eat to grow 351 00:20:33,600 --> 00:20:36,560 Speaker 1: so big? Well, it turns out in reality, they just 352 00:20:36,760 --> 00:20:40,120 Speaker 1: they eat plants. These are entirely herbivorous creatures. There are 353 00:20:40,240 --> 00:20:45,280 Speaker 1: turtles and tortoises that eat other things, but these tortoises 354 00:20:45,320 --> 00:20:49,720 Speaker 1: are entirely plant eaters, and so especially in the lowlands, 355 00:20:49,880 --> 00:20:55,280 Speaker 1: especially the the saddleback tortoises, will eat succulent cactus. This 356 00:20:55,400 --> 00:20:58,600 Speaker 1: is something Darwin identifies. He says they especially favor the 357 00:20:58,640 --> 00:21:00,920 Speaker 1: cactus if they live in the low and arid parts 358 00:21:00,920 --> 00:21:03,040 Speaker 1: of the islands where there is little or no water. 359 00:21:03,440 --> 00:21:07,040 Speaker 1: Of course the cactus becomes a principal water source, but 360 00:21:07,119 --> 00:21:10,199 Speaker 1: also they eat tree leaves and berries as well as 361 00:21:10,240 --> 00:21:14,439 Speaker 1: green lichen UH and their diet somewhat depends on which 362 00:21:14,480 --> 00:21:17,359 Speaker 1: species they are and which part of the islands which 363 00:21:17,440 --> 00:21:20,320 Speaker 1: microclimate they inhabit. Like the ones that live higher up 364 00:21:20,359 --> 00:21:23,880 Speaker 1: in the UH the highlands with more lush vegetation probably 365 00:21:23,960 --> 00:21:27,600 Speaker 1: feed on more leafy stuff, and the ones that live 366 00:21:27,680 --> 00:21:31,320 Speaker 1: more in the arid regions probably feed on more cactus. Yeah, 367 00:21:31,320 --> 00:21:35,000 Speaker 1: the ones I got to actually observe in the in 368 00:21:35,040 --> 00:21:38,359 Speaker 1: the wild as it were on San Cristobule and on 369 00:21:38,440 --> 00:21:42,480 Speaker 1: Santa Cruz Island. They they were definitely eating the leafy 370 00:21:42,520 --> 00:21:45,440 Speaker 1: green stuff. But I got to see plenty of the cacti, 371 00:21:45,560 --> 00:21:50,040 Speaker 1: which of course have coexisted with the tortoises long enough 372 00:21:50,119 --> 00:21:53,720 Speaker 1: that they have they have particular adaptations, like they have 373 00:21:53,800 --> 00:21:57,560 Speaker 1: been changed by cohabitation with the tortoise as well. And 374 00:21:57,640 --> 00:22:00,199 Speaker 1: the most remarkable of these are the ones that they 375 00:22:00,240 --> 00:22:03,600 Speaker 1: basically seemed to grow up like trees and then branch 376 00:22:03,640 --> 00:22:07,040 Speaker 1: out because they're trying to reach and they're reaching an 377 00:22:07,040 --> 00:22:11,760 Speaker 1: optimal height at which they're hopefully above the reach of 378 00:22:11,800 --> 00:22:14,920 Speaker 1: the tortoise. There is one type of cactus that there's 379 00:22:14,960 --> 00:22:17,000 Speaker 1: a great picture of in this book by Creature in 380 00:22:17,080 --> 00:22:20,000 Speaker 1: Laughlin I've been talking about. It's called a candelabray cactus, 381 00:22:20,440 --> 00:22:24,040 Speaker 1: and I thought it was beautiful because the branches look 382 00:22:24,160 --> 00:22:29,320 Speaker 1: to me like giant green tarantula legs. They kind of 383 00:22:29,320 --> 00:22:32,680 Speaker 1: have these lobes that look like little hairy legs segments 384 00:22:32,720 --> 00:22:35,440 Speaker 1: on a large spider. Yeah. Yeah, And it's a nice 385 00:22:35,440 --> 00:22:38,080 Speaker 1: picture too, because you gotta you gotta flamingo in there. Um. 386 00:22:38,119 --> 00:22:42,399 Speaker 1: I did get to see a few flamingos on Seymour Island, 387 00:22:42,400 --> 00:22:46,720 Speaker 1: I believe. But the tortoises just generally seemed to eat 388 00:22:46,800 --> 00:22:50,240 Speaker 1: all kinds of foods that would look to us quite hostile. So, 389 00:22:50,440 --> 00:22:53,200 Speaker 1: of course the the ones in the lowlands are gonna 390 00:22:53,240 --> 00:22:56,760 Speaker 1: eat a lot of cactus, but they also apparently eat 391 00:22:56,840 --> 00:23:01,200 Speaker 1: plenty of poison apple or men's nillo, which is toxic. 392 00:23:01,359 --> 00:23:05,160 Speaker 1: It has a sap that is poisonous to other creatures. 393 00:23:05,200 --> 00:23:07,919 Speaker 1: But uh, and I think it can can cause blistering 394 00:23:07,960 --> 00:23:11,360 Speaker 1: if you touch it. But apparently the tortoises just chow 395 00:23:11,440 --> 00:23:14,399 Speaker 1: down on this stuff, doesn't bother them. Yeah. On on 396 00:23:14,480 --> 00:23:18,520 Speaker 1: San Cristoble Island, of the area where we're encountering the tortoises, 397 00:23:18,800 --> 00:23:21,760 Speaker 1: they had signs everywhere, do not touch the apples, do 398 00:23:21,800 --> 00:23:24,800 Speaker 1: not certainly do not eat the apples. Leave this to 399 00:23:24,880 --> 00:23:28,560 Speaker 1: the tortoises. Now, coming back to Darwin's writing on the tortoises, 400 00:23:28,600 --> 00:23:32,560 Speaker 1: he also observes their relationship with water. He says they're notable, 401 00:23:32,600 --> 00:23:35,439 Speaker 1: of course for their ability to survive without water for 402 00:23:35,480 --> 00:23:39,200 Speaker 1: a very long time, but when they get access to water. 403 00:23:39,840 --> 00:23:42,760 Speaker 1: They go hog wild. They love it, the spring water 404 00:23:42,840 --> 00:23:45,160 Speaker 1: and the mud puddles. They'll just get in there and 405 00:23:45,160 --> 00:23:48,600 Speaker 1: and settle in uh, sometimes for days at a time. 406 00:23:49,000 --> 00:23:52,159 Speaker 1: And when they when they're drinking, they will just gulp 407 00:23:52,280 --> 00:23:56,240 Speaker 1: huge mouthfuls of water for a long time. And Darwin 408 00:23:56,400 --> 00:23:59,639 Speaker 1: even this leads into him writing a really bizarre and 409 00:23:59,760 --> 00:24:02,199 Speaker 1: it out that I had to share. So he says, quote, 410 00:24:02,440 --> 00:24:04,760 Speaker 1: for some time after a visit to the springs, their 411 00:24:04,920 --> 00:24:08,119 Speaker 1: urinary bladders are distended with fluid which is said to 412 00:24:08,240 --> 00:24:12,199 Speaker 1: gradually which is said to gradually decrease in volume and 413 00:24:12,280 --> 00:24:15,520 Speaker 1: to become less pure. The inhabitants, when walking in the 414 00:24:15,560 --> 00:24:18,639 Speaker 1: lower district and overcome with thirst, often take advantage of 415 00:24:18,680 --> 00:24:22,520 Speaker 1: this circumstance and drink the contents of the bladder if full. 416 00:24:23,280 --> 00:24:25,879 Speaker 1: In one tortoise I saw killed, the fluid was quite 417 00:24:26,040 --> 00:24:31,280 Speaker 1: limpid and had only a very slightly bitter taste. The inhabitants, however, 418 00:24:31,359 --> 00:24:34,520 Speaker 1: always first drink the water in the pericardium, which is 419 00:24:34,760 --> 00:24:38,160 Speaker 1: the membrane I believe as surrounding the heart tissue, which 420 00:24:38,240 --> 00:24:41,880 Speaker 1: is described as being best. So that's right, drinking the 421 00:24:41,920 --> 00:24:45,320 Speaker 1: water from a tortoise's heart or from a tortoise's bladder, 422 00:24:45,320 --> 00:24:49,399 Speaker 1: and Darwin tasted the tortoise bladder water. I guess I 423 00:24:49,440 --> 00:24:54,240 Speaker 1: should be happy for this, that they're using all parts 424 00:24:54,240 --> 00:24:56,840 Speaker 1: of the tortoise conceivably in doing this, But of course 425 00:24:56,880 --> 00:25:00,520 Speaker 1: this is still kind of sad to imagine. Yeah, but 426 00:25:00,720 --> 00:25:04,679 Speaker 1: also from just a purely anatomical level, this is of 427 00:25:04,720 --> 00:25:09,200 Speaker 1: course amazing. Now Darwin goes on to talk about how 428 00:25:09,240 --> 00:25:13,080 Speaker 1: impressed he is by the long determined journeys that some 429 00:25:13,160 --> 00:25:17,440 Speaker 1: of these tortoises make between uh. He believes what the 430 00:25:17,880 --> 00:25:21,080 Speaker 1: point of these journeys is is between highland water sources 431 00:25:21,160 --> 00:25:24,880 Speaker 1: and usual breeding grounds in the lower districts. I don't 432 00:25:24,920 --> 00:25:26,919 Speaker 1: know if that holds up as the main reason for 433 00:25:26,960 --> 00:25:29,919 Speaker 1: these journeys today, uh, though I do think some of 434 00:25:29,920 --> 00:25:33,440 Speaker 1: these uh tortoises do make journeys between the highlands and 435 00:25:33,480 --> 00:25:37,080 Speaker 1: the lowlands for the purpose of depositing eggs the females 436 00:25:37,160 --> 00:25:40,000 Speaker 1: do after mating season. But there are also journeys I 437 00:25:40,040 --> 00:25:42,480 Speaker 1: think having to do with with food resources in the 438 00:25:42,520 --> 00:25:45,479 Speaker 1: different seasons and so forth. But anyway, Darwin says, you know, 439 00:25:45,520 --> 00:25:48,639 Speaker 1: although the tortoises are pretty slow in their movements, you 440 00:25:48,640 --> 00:25:51,280 Speaker 1: would be surprised how much ground they cover over time 441 00:25:51,359 --> 00:25:54,480 Speaker 1: due to sheer determination. He estimates that they're going to 442 00:25:54,560 --> 00:25:57,879 Speaker 1: move sixty yards in ten minutes, which is three hundred 443 00:25:57,880 --> 00:26:00,800 Speaker 1: and sixty yards in an hour, or about four miles 444 00:26:00,800 --> 00:26:04,919 Speaker 1: a day. Yeah, it's pretty remarkable, and of course nowadays, 445 00:26:04,960 --> 00:26:07,680 Speaker 1: of course that everything has been shifted around a bit. Uh. 446 00:26:07,800 --> 00:26:10,480 Speaker 1: You know all these invasive species, not only the such 447 00:26:10,520 --> 00:26:14,919 Speaker 1: harmful invasive species as UH pigs and UH and goats 448 00:26:14,960 --> 00:26:17,800 Speaker 1: that were introduced and then their populations have been dealt 449 00:26:17,840 --> 00:26:20,400 Speaker 1: with the varying degrees, but you also have, of course, 450 00:26:20,400 --> 00:26:23,520 Speaker 1: have plants to think about, um. And so in some 451 00:26:23,560 --> 00:26:26,399 Speaker 1: cases you have things like berries that are that are 452 00:26:26,440 --> 00:26:29,480 Speaker 1: now grown in the Galapagos and may occur wild in 453 00:26:29,520 --> 00:26:32,880 Speaker 1: some cases, and of course the tortoises love those even 454 00:26:32,920 --> 00:26:35,440 Speaker 1: though they are not native, and so you may see 455 00:26:35,480 --> 00:26:39,240 Speaker 1: that uh interfere with their their movements a bit. But yeah, basically, 456 00:26:39,960 --> 00:26:43,760 Speaker 1: through modern conservation and through modern tracking technology, you can 457 00:26:43,800 --> 00:26:47,480 Speaker 1: actually see all of these tortoise movements plotted out on 458 00:26:47,600 --> 00:26:51,920 Speaker 1: maps and it's quite impressive. UM. I think there their 459 00:26:51,960 --> 00:26:55,240 Speaker 1: movements in these cases help illustrate why they're so crucial 460 00:26:55,320 --> 00:26:58,560 Speaker 1: for the island ecosystem that they thrive in. They eat 461 00:26:58,640 --> 00:27:01,720 Speaker 1: so much and they're slow, they do cover a lot 462 00:27:01,720 --> 00:27:06,600 Speaker 1: of ground and defecate to spread speeds, spread seeds rather uh. 463 00:27:06,720 --> 00:27:08,720 Speaker 1: And this is very much in line with other megafauna 464 00:27:08,760 --> 00:27:12,480 Speaker 1: that you encounter in in other ecosystems as well as 465 00:27:12,520 --> 00:27:15,400 Speaker 1: the Remember, if you think back to our episode on 466 00:27:15,520 --> 00:27:18,640 Speaker 1: our episodes on the giant moa bird, which of course 467 00:27:18,720 --> 00:27:21,480 Speaker 1: is extinct, but would have we still see like the 468 00:27:21,520 --> 00:27:26,840 Speaker 1: footprint of their ecological importance in the areas that they 469 00:27:26,880 --> 00:27:30,560 Speaker 1: occupied because they were vital for consuming plants and the 470 00:27:30,640 --> 00:27:34,960 Speaker 1: spreading those seeds through defecation. Yeah, there is a great 471 00:27:34,960 --> 00:27:37,399 Speaker 1: passage in the book by Creature in Laughlin where they 472 00:27:37,400 --> 00:27:41,679 Speaker 1: talk about the importance of the tortoise in spreading a 473 00:27:42,160 --> 00:27:47,440 Speaker 1: type a species of wild Galapagos tomato plant which apparently 474 00:27:47,520 --> 00:27:51,359 Speaker 1: it only the seeds only germinate under very specific conditions, 475 00:27:51,359 --> 00:27:54,959 Speaker 1: such as being exposed to acid for a long period 476 00:27:54,960 --> 00:27:57,479 Speaker 1: of time. Now, how does that happen? What happens in 477 00:27:57,560 --> 00:28:00,760 Speaker 1: the digestive system of the tortoise. So like they take 478 00:28:00,800 --> 00:28:04,280 Speaker 1: this in, the seed gets exposed to the acid within 479 00:28:04,359 --> 00:28:08,040 Speaker 1: the digestive juices and then it gets it travels with 480 00:28:08,080 --> 00:28:12,200 Speaker 1: the tortoise along ways away from its original location, so 481 00:28:12,400 --> 00:28:15,320 Speaker 1: that's also good for dispersal. And then once the tortoise 482 00:28:15,400 --> 00:28:17,359 Speaker 1: poops it out, it of course has a bunch of 483 00:28:17,440 --> 00:28:21,600 Speaker 1: nutritious fecal matters surrounding it to help it grow. Yeah, 484 00:28:21,600 --> 00:28:24,800 Speaker 1: I've got I did get to poke uh some some 485 00:28:24,840 --> 00:28:27,000 Speaker 1: tortoise dung with a stick, my son and I did, 486 00:28:27,040 --> 00:28:29,560 Speaker 1: and we got to look all in there. It's a uh, 487 00:28:29,640 --> 00:28:33,600 Speaker 1: you know, quite fascinating. Um. I think some stats would 488 00:28:33,600 --> 00:28:36,200 Speaker 1: really help drive home though. While the tortoises so great 489 00:28:36,280 --> 00:28:39,719 Speaker 1: at this and I got these from Seed Dispersal by 490 00:28:39,800 --> 00:28:43,000 Speaker 1: Galapagos Tortoises by Blake at All, published in the Journal 491 00:28:43,040 --> 00:28:47,680 Speaker 1: of Biogeography from so In this particular survey, the researchers 492 00:28:47,720 --> 00:28:50,560 Speaker 1: looked at one and twenty fresh dung piles in both 493 00:28:50,800 --> 00:28:55,240 Speaker 1: agricultural and national park land. They found seeds from more 494 00:28:55,280 --> 00:28:58,240 Speaker 1: than forty five plant species in these dung piles, eleven 495 00:28:58,280 --> 00:29:00,480 Speaker 1: of which were from introduced species. Is you know, like 496 00:29:00,560 --> 00:29:05,200 Speaker 1: various berries and whatnot. A per tortoise average of four 497 00:29:05,280 --> 00:29:08,720 Speaker 1: hundred and sixty four seeds and two point eight species 498 00:29:08,760 --> 00:29:11,880 Speaker 1: per dung pile was detected. Now, this is where it 499 00:29:11,880 --> 00:29:14,520 Speaker 1: gets kind of interesting because Okay, we've already established that, yes, 500 00:29:14,520 --> 00:29:17,720 Speaker 1: they eat a lot, they travel farther than you might think, 501 00:29:18,200 --> 00:29:21,040 Speaker 1: but how how long does it take for them to 502 00:29:21,080 --> 00:29:25,000 Speaker 1: process their food? Uh, things go a little slower with 503 00:29:25,000 --> 00:29:30,200 Speaker 1: with the Galapagos tortoises. The mean digesta retention time for 504 00:29:30,240 --> 00:29:34,480 Speaker 1: a tortoise is twelve days, but twenty eight day retention 505 00:29:34,560 --> 00:29:38,440 Speaker 1: times have been reported. So that's the that's the time 506 00:29:38,480 --> 00:29:41,360 Speaker 1: it takes for the food that they've consumed to process 507 00:29:41,440 --> 00:29:44,120 Speaker 1: through their body and become done, so they can really 508 00:29:44,120 --> 00:29:47,440 Speaker 1: cover some ground in that time. Yeah. During that time, 509 00:29:47,520 --> 00:29:50,480 Speaker 1: according to this paper, the tortoise may travel between three 510 00:29:50,560 --> 00:29:53,640 Speaker 1: hundred and ninety four and four thousand, three hundred fifty 511 00:29:53,640 --> 00:29:56,600 Speaker 1: five meters on the high end, that's two point seven 512 00:29:56,600 --> 00:29:59,640 Speaker 1: miles or four point three kilometers. So you can see 513 00:29:59,640 --> 00:30:02,280 Speaker 1: how these hortises would play an incredibly important role in 514 00:30:02,560 --> 00:30:07,560 Speaker 1: helping the reproduction and dispersal of local flora. Yeah. Absolutely, 515 00:30:07,600 --> 00:30:10,120 Speaker 1: I mean within it, as with any species, they don't 516 00:30:10,160 --> 00:30:13,280 Speaker 1: they're not existing in isolation. In their ecosystem. They have 517 00:30:13,360 --> 00:30:16,200 Speaker 1: a role, they have a they have a place in it, 518 00:30:16,600 --> 00:30:19,640 Speaker 1: and if if you disrupt them, if you disrupt their 519 00:30:19,680 --> 00:30:22,600 Speaker 1: numbers or in the very worst case scenarios. If they 520 00:30:23,040 --> 00:30:26,880 Speaker 1: their extinction is brought about, Uh, then there is there's 521 00:30:26,920 --> 00:30:29,960 Speaker 1: something missing. There's you end up pulling the carpet out 522 00:30:29,960 --> 00:30:34,280 Speaker 1: from everything. And unlike with with the parlor trick, all 523 00:30:34,320 --> 00:30:36,200 Speaker 1: the plates and the dishes are not necessarily going to 524 00:30:36,280 --> 00:30:48,120 Speaker 1: stay standing up. Now. Uh, we've been talking about a 525 00:30:48,120 --> 00:30:51,560 Speaker 1: lot of the predation and hunting of these tortoises. But 526 00:30:52,240 --> 00:30:57,400 Speaker 1: barring that, how do tortoises die? What happens? Uh? Well, 527 00:30:57,600 --> 00:31:00,280 Speaker 1: Darwin writes, quote the young tortoises as soon as they 528 00:31:00,280 --> 00:31:02,800 Speaker 1: are hatched, fall praying great numbers to the carry and 529 00:31:02,920 --> 00:31:06,440 Speaker 1: feeding buzzard. I think that would actually be referring probably 530 00:31:06,480 --> 00:31:09,480 Speaker 1: to the galapagost hawk um, unless he's talking about some 531 00:31:09,520 --> 00:31:13,960 Speaker 1: other species that that came in after humans arrived. But 532 00:31:15,120 --> 00:31:17,720 Speaker 1: Darwin goes on, the old ones seemed to die generally 533 00:31:18,080 --> 00:31:22,800 Speaker 1: from accidents, as from falling down precipices. At least several 534 00:31:22,840 --> 00:31:25,680 Speaker 1: of the inhabitants told me that they never found one 535 00:31:25,760 --> 00:31:29,320 Speaker 1: dead without some evident cause, which that kind of gave 536 00:31:29,360 --> 00:31:33,440 Speaker 1: me a shiver. Yeah, yeah, I mean it's it's it's 537 00:31:33,480 --> 00:31:37,320 Speaker 1: just impressive how long they live. Um that Now to 538 00:31:37,400 --> 00:31:39,320 Speaker 1: the first point about predation is worth pointing out the 539 00:31:39,440 --> 00:31:42,400 Speaker 1: tortoise sanctuaries that are up and running now. They care 540 00:31:42,480 --> 00:31:45,080 Speaker 1: for the little ones to protect them from you know, 541 00:31:45,160 --> 00:31:47,480 Speaker 1: not only the hawk, but also all these these these 542 00:31:47,520 --> 00:31:51,520 Speaker 1: introduced species that maybe about UM once they get big enough. 543 00:31:51,560 --> 00:31:53,920 Speaker 1: Though yeah, there's there's only really three ways they're going 544 00:31:53,960 --> 00:31:59,560 Speaker 1: to die old age eventually, UM, accident vehicular especially of 545 00:31:59,560 --> 00:32:03,920 Speaker 1: course being the main threat though UM on the glactos items. 546 00:32:03,920 --> 00:32:06,719 Speaker 1: Today a lot of a lot of you know, laws 547 00:32:06,800 --> 00:32:09,719 Speaker 1: and messaging have been put in place to prevent this 548 00:32:09,760 --> 00:32:12,240 Speaker 1: from occurring. And then of course in the past human 549 00:32:12,320 --> 00:32:15,360 Speaker 1: hunting was the big thing. Now you mentioned they can 550 00:32:15,440 --> 00:32:17,520 Speaker 1: die of old age, of course they do, but that 551 00:32:17,560 --> 00:32:20,440 Speaker 1: can take a good long while. I was reading about 552 00:32:20,480 --> 00:32:24,560 Speaker 1: this in a Creature in Laughlin, and uh they say 553 00:32:24,640 --> 00:32:26,920 Speaker 1: that it's possible, though we have no way to know 554 00:32:27,000 --> 00:32:29,840 Speaker 1: for sure, that there may be tortoises still alive on 555 00:32:29,880 --> 00:32:33,480 Speaker 1: the islands that were present when Darwin visited in eighteen 556 00:32:33,520 --> 00:32:37,440 Speaker 1: thirty five. And Uh. A Galapagos tortoise named Harriet lived 557 00:32:37,440 --> 00:32:40,120 Speaker 1: to an estimated age of a hundred and seventy five 558 00:32:40,320 --> 00:32:44,120 Speaker 1: before she died in an Australian zoo in two thousand six, 559 00:32:44,200 --> 00:32:47,880 Speaker 1: so they can live a long long time. Yeah, I've 560 00:32:47,880 --> 00:32:49,840 Speaker 1: also I was doing some crunching on this as well. 561 00:32:49,880 --> 00:32:51,440 Speaker 1: I think one of the sources I was looking at 562 00:32:51,520 --> 00:32:54,160 Speaker 1: had listed like a hundred and seventy one years as 563 00:32:54,200 --> 00:32:57,800 Speaker 1: being like I wanted to the the oldest stage is 564 00:32:57,840 --> 00:32:59,880 Speaker 1: known for the tortoises. And even if you're just gonna 565 00:32:59,880 --> 00:33:03,240 Speaker 1: go go with that, if you consider the idea that 566 00:33:03,280 --> 00:33:06,360 Speaker 1: you have a tortoise born in eighteen thirty five when 567 00:33:06,400 --> 00:33:08,920 Speaker 1: Darwin is visiting, if it lived a hundred and seventy 568 00:33:08,920 --> 00:33:10,960 Speaker 1: one years, it would live to the year two thousand 569 00:33:11,040 --> 00:33:13,959 Speaker 1: and six, which is just crazy to think about the 570 00:33:14,000 --> 00:33:19,080 Speaker 1: idea that just one tortoise lifetime would bridge our time 571 00:33:19,120 --> 00:33:22,560 Speaker 1: to the time of Darwin, and that a single tortoise 572 00:33:22,600 --> 00:33:27,600 Speaker 1: lifetime could encompass basically the two worst centuries of the 573 00:33:27,600 --> 00:33:32,280 Speaker 1: the impact of humanity on Glapacos tortoise numbers as well. Now, 574 00:33:32,280 --> 00:33:34,640 Speaker 1: again not to come back too much to the the 575 00:33:34,680 --> 00:33:37,640 Speaker 1: horrors of human tortoise interaction, but yeah, there are these 576 00:33:37,760 --> 00:33:41,920 Speaker 1: accounts you read too of like times when uh roads 577 00:33:41,960 --> 00:33:46,000 Speaker 1: to various villages were just aligned with like the bones 578 00:33:46,080 --> 00:33:49,800 Speaker 1: or the shells of of these creatures. Um it was 579 00:33:50,000 --> 00:33:53,000 Speaker 1: it was a rough time to be a glapacost tortoise. Yes, 580 00:33:53,320 --> 00:33:57,520 Speaker 1: uh no, Now I think it's worth talking about Galapagos 581 00:33:57,600 --> 00:34:02,040 Speaker 1: tortoise mating and reproduction, in which there's some interesting stuff. Uh. 582 00:34:02,200 --> 00:34:05,120 Speaker 1: For one thing I was reading about. Uh maybe we 583 00:34:05,120 --> 00:34:07,000 Speaker 1: can get to the actual mating in a minute, But 584 00:34:07,200 --> 00:34:11,040 Speaker 1: first I was reading a section in uh in Creature 585 00:34:11,040 --> 00:34:14,880 Speaker 1: in Laughlin about the nests and egg laying of the 586 00:34:14,920 --> 00:34:19,680 Speaker 1: glopaost tortoise. So mating season typically occurs during the rainy season, 587 00:34:20,280 --> 00:34:24,440 Speaker 1: and after having made it, a female tortoise will generally 588 00:34:24,520 --> 00:34:28,360 Speaker 1: travel toward the arid lowlands to build a nest. Darwin 589 00:34:28,440 --> 00:34:30,920 Speaker 1: has a section about this where he correctly observes that 590 00:34:31,000 --> 00:34:33,960 Speaker 1: they will seek out arid sandy soil to dig a 591 00:34:34,000 --> 00:34:36,560 Speaker 1: nest in. But then he says others. He says, sometimes 592 00:34:36,640 --> 00:34:39,600 Speaker 1: they will just drop their eggs wherever, like in a precipice, 593 00:34:39,680 --> 00:34:42,399 Speaker 1: like in a crevice in the rocks. I didn't find 594 00:34:42,400 --> 00:34:45,040 Speaker 1: any other evidence of that, so maybe that was true 595 00:34:45,040 --> 00:34:47,640 Speaker 1: when he was there, But I'm not aware of other 596 00:34:47,680 --> 00:34:50,319 Speaker 1: evidence for that other than what Darwin says. But uh, 597 00:34:50,520 --> 00:34:53,160 Speaker 1: generally what they do is they're gonna dig down in 598 00:34:53,239 --> 00:34:57,080 Speaker 1: the arid regions now, and for the saddleback tortoises, which 599 00:34:57,120 --> 00:34:59,239 Speaker 1: tend to live more in the lowlands, this is not 600 00:34:59,320 --> 00:35:01,719 Speaker 1: much of a trip, but for the domed tortoises it 601 00:35:01,760 --> 00:35:04,279 Speaker 1: can be a really great journey down from the highlands 602 00:35:04,320 --> 00:35:06,640 Speaker 1: into the place where they're going to lay the lay 603 00:35:06,680 --> 00:35:10,200 Speaker 1: the eggs, and the eggs are laid sometime between June 604 00:35:10,200 --> 00:35:13,440 Speaker 1: and December. A clutch can contain anywhere from like two 605 00:35:13,480 --> 00:35:16,719 Speaker 1: to twenty eggs. The eggs are sort of billiard ball 606 00:35:16,800 --> 00:35:20,120 Speaker 1: sized or maybe a little bit larger. And the nest 607 00:35:20,160 --> 00:35:23,920 Speaker 1: building process is what interested me because apparently it involves 608 00:35:23,920 --> 00:35:27,520 Speaker 1: a good bit of p So the tortoise will find 609 00:35:27,560 --> 00:35:29,640 Speaker 1: a spot in the soil and she will dig a 610 00:35:29,640 --> 00:35:32,880 Speaker 1: hole about thirty centimeters deep, scooping the earth out with 611 00:35:32,920 --> 00:35:36,360 Speaker 1: her hind legs, and this is a a an involved 612 00:35:36,360 --> 00:35:39,360 Speaker 1: process that can take up to about twelve hours, and 613 00:35:39,400 --> 00:35:42,479 Speaker 1: the tortoise will often urinate on the soil in order 614 00:35:42,520 --> 00:35:46,040 Speaker 1: to soften it for digging. But the mother tortoise, after 615 00:35:46,200 --> 00:35:48,080 Speaker 1: she lays her eggs in the hole and covers it up, 616 00:35:48,160 --> 00:35:51,520 Speaker 1: then also peas on the soil again to form a 617 00:35:51,600 --> 00:35:55,080 Speaker 1: kind of cement layer. In it. This is interesting. We've 618 00:35:55,080 --> 00:35:58,520 Speaker 1: we've we've discussed a number of different like nest building, 619 00:35:58,600 --> 00:36:02,040 Speaker 1: egg laying scenarios over the years, but I don't remember 620 00:36:02,080 --> 00:36:05,040 Speaker 1: one that was so urine intensive. Yeah, there may be 621 00:36:05,080 --> 00:36:07,919 Speaker 1: other species that do p cement, but this is the 622 00:36:07,920 --> 00:36:11,200 Speaker 1: first time I remember reading about this. Uh So, anyway, 623 00:36:11,520 --> 00:36:14,000 Speaker 1: the the eggs incubate in the cemented earth for like 624 00:36:14,040 --> 00:36:17,160 Speaker 1: four to eight months, where the sex of the hatchling 625 00:36:17,200 --> 00:36:20,600 Speaker 1: is ultimately determined by the temperature which the egg incubates. 626 00:36:20,640 --> 00:36:23,839 Speaker 1: This kind of interesting. It's not chromosome ely determined as 627 00:36:23,840 --> 00:36:27,200 Speaker 1: it is for some other animals. And uh So, afterwards 628 00:36:27,239 --> 00:36:29,399 Speaker 1: they dig their way out of the nest to begin 629 00:36:29,480 --> 00:36:32,320 Speaker 1: their lives. And of course this is the most vulnerable 630 00:36:32,360 --> 00:36:36,040 Speaker 1: time for a Galapagos tortoise when they're a hatchling, but 631 00:36:36,360 --> 00:36:38,520 Speaker 1: they are the ones that survived make it out. They 632 00:36:38,560 --> 00:36:41,520 Speaker 1: they find food, they avoid predators, and they eventually grow up, 633 00:36:41,520 --> 00:36:43,960 Speaker 1: though apparently the growing up also takes a good bit 634 00:36:44,000 --> 00:36:48,600 Speaker 1: of time. The tortoises do everything pretty slow, including reaching maturity. 635 00:36:48,719 --> 00:36:52,280 Speaker 1: I've read that they don't reach sexual maturity until several 636 00:36:52,320 --> 00:36:57,080 Speaker 1: decades later. The mating itself is also kind of interesting. 637 00:36:57,400 --> 00:37:01,080 Speaker 1: Because the basically consists of the mails chasing the females 638 00:37:01,120 --> 00:37:04,640 Speaker 1: around until they can corner them. But then there's also, 639 00:37:05,400 --> 00:37:09,320 Speaker 1: given that these are large shelled creatures, there the male's 640 00:37:09,360 --> 00:37:12,520 Speaker 1: shell has like an intention on the bottom that allows 641 00:37:12,560 --> 00:37:15,840 Speaker 1: for it to mount the female, because otherwise, like unless 642 00:37:15,880 --> 00:37:18,560 Speaker 1: there was some arrangement of the shells in this capacity, 643 00:37:18,920 --> 00:37:22,120 Speaker 1: that they would not be compatible. Right. And there was 644 00:37:22,160 --> 00:37:24,600 Speaker 1: also a fact I came across that I thought was 645 00:37:24,600 --> 00:37:27,359 Speaker 1: funny in in this book they talked about how the 646 00:37:27,480 --> 00:37:30,440 Speaker 1: larger size of the Galapagos tortoise can make the physical 647 00:37:30,480 --> 00:37:34,480 Speaker 1: active mating sometimes kind of cumbersome and laborious, and the 648 00:37:34,520 --> 00:37:39,200 Speaker 1: authors note that quote, males often slide off, sometimes even inadvertently, 649 00:37:39,280 --> 00:37:42,759 Speaker 1: landing upside down, at which point they must right themselves 650 00:37:42,800 --> 00:37:45,160 Speaker 1: and try again, which I don't know if it's juvenile 651 00:37:45,200 --> 00:37:47,760 Speaker 1: that I found that funny, but I did. The authors 652 00:37:47,800 --> 00:37:52,280 Speaker 1: also note that the male tortoises sometimes get confused. For example, 653 00:37:52,280 --> 00:37:56,360 Speaker 1: they try to mate with large rocks. Well, that's just 654 00:37:56,520 --> 00:37:58,360 Speaker 1: in and of itself funny. We we can't help but 655 00:37:58,480 --> 00:38:02,600 Speaker 1: laugh at that. But there's also surprising for these very 656 00:38:02,600 --> 00:38:06,680 Speaker 1: slow moving animals, there is some surprisingly fierce competition between 657 00:38:06,800 --> 00:38:10,360 Speaker 1: males for access to mates, and Darwin notes this. He 658 00:38:10,360 --> 00:38:13,080 Speaker 1: says during breeding season, you can hear the mails emit 659 00:38:13,200 --> 00:38:16,880 Speaker 1: what he calls a horse roar, and I think this 660 00:38:17,000 --> 00:38:21,080 Speaker 1: roar is probably indicative of of male on male competition, 661 00:38:21,160 --> 00:38:24,040 Speaker 1: which sometimes leads to these mock fights where they will 662 00:38:24,120 --> 00:38:26,279 Speaker 1: raise their necks up at each other. Rob. I think 663 00:38:26,280 --> 00:38:29,960 Speaker 1: you actually maybe saw one of these going on. Yes, 664 00:38:30,080 --> 00:38:33,160 Speaker 1: I got to see this happen and I actually got 665 00:38:33,160 --> 00:38:36,279 Speaker 1: to film it. Uh able to my wife was like, quick, 666 00:38:36,280 --> 00:38:37,719 Speaker 1: get your get your camera out and make sure you're 667 00:38:37,719 --> 00:38:40,080 Speaker 1: getting this, and so I did. Uh. Yeah. It's amazing 668 00:38:40,120 --> 00:38:43,719 Speaker 1: to watch because you'll have these two lumbering giants that 669 00:38:43,800 --> 00:38:45,880 Speaker 1: are kind of on a on a collision course with 670 00:38:45,920 --> 00:38:48,120 Speaker 1: each other, and you're like, what's gonna happen, What's gonna happen? 671 00:38:48,400 --> 00:38:51,080 Speaker 1: And then as they get closer, they'll both rear their 672 00:38:51,120 --> 00:38:54,759 Speaker 1: heads up and they'll have the showdown. That doesn't it 673 00:38:54,760 --> 00:38:57,359 Speaker 1: does not come to blows or bites or anything like that, 674 00:38:57,600 --> 00:38:59,880 Speaker 1: but it is a competition to see who to determine 675 00:38:59,880 --> 00:39:03,799 Speaker 1: who is the tallest and the tallest tortoise, who are 676 00:39:03,840 --> 00:39:05,880 Speaker 1: the one that can raise its head up the highest 677 00:39:06,560 --> 00:39:09,319 Speaker 1: he's the winner, and the other one accepts defeat and 678 00:39:09,600 --> 00:39:12,960 Speaker 1: carries on. And that's that's as violent as it seems 679 00:39:12,960 --> 00:39:15,319 Speaker 1: to get. But it's it's spectacular to watch. And yeah, 680 00:39:15,360 --> 00:39:19,320 Speaker 1: this was the finest nature footage I have ever captured 681 00:39:19,400 --> 00:39:22,160 Speaker 1: or will ever capture. Now, one last thing I wanted 682 00:39:22,160 --> 00:39:24,279 Speaker 1: to read from Darwin here where he's talking about the 683 00:39:24,320 --> 00:39:27,879 Speaker 1: tortoise's reaction to humans. This is another infamous section from 684 00:39:27,920 --> 00:39:31,920 Speaker 1: the Voyage of the Beagle chapter. Darwin says, I was 685 00:39:31,960 --> 00:39:35,200 Speaker 1: always amused when overtaking one of these great monsters, as 686 00:39:35,239 --> 00:39:38,400 Speaker 1: it was quietly pacing along, to see how suddenly the 687 00:39:38,480 --> 00:39:41,160 Speaker 1: instant I passed, it would draw in its head and 688 00:39:41,280 --> 00:39:44,200 Speaker 1: legs and, uttering a deep hiss, fall to the ground 689 00:39:44,280 --> 00:39:48,120 Speaker 1: with a heavy sound, as if struck dead. I frequently 690 00:39:48,320 --> 00:39:51,560 Speaker 1: got on their backs, and then giving a few raps 691 00:39:51,600 --> 00:39:54,120 Speaker 1: on the hinder part of the shells, they would rise 692 00:39:54,239 --> 00:39:56,880 Speaker 1: up and walk away. But I found it very difficult 693 00:39:56,920 --> 00:40:02,000 Speaker 1: to keep my balance. Oh, Charles, no doing why you're 694 00:40:02,040 --> 00:40:05,399 Speaker 1: writing a tortoise? Um? I mean it is kind of 695 00:40:06,000 --> 00:40:09,719 Speaker 1: I mean it based on this account, the tortoise is 696 00:40:09,760 --> 00:40:12,520 Speaker 1: doing exactly what you know I observed in all these 697 00:40:12,520 --> 00:40:15,239 Speaker 1: sources say they do if someone gets too close or 698 00:40:15,239 --> 00:40:17,799 Speaker 1: something is too close. But it is kind of interesting 699 00:40:18,120 --> 00:40:21,600 Speaker 1: this added detail that apparently eventually the tortoise is like, Okay, 700 00:40:21,960 --> 00:40:24,160 Speaker 1: I guess this weird British man is not going away. 701 00:40:24,640 --> 00:40:27,560 Speaker 1: I have things to do in places to be I'm 702 00:40:27,560 --> 00:40:30,080 Speaker 1: just gonna start walking around with him on there and 703 00:40:30,120 --> 00:40:32,560 Speaker 1: maybe I can sort of shake him off. Yeah, and 704 00:40:32,719 --> 00:40:35,879 Speaker 1: this is actually not an isolated report. Again, we are 705 00:40:35,920 --> 00:40:39,239 Speaker 1: not recommending writing the tortoises, but other other people talk 706 00:40:39,320 --> 00:40:41,239 Speaker 1: about how well you can get on their backs and 707 00:40:41,320 --> 00:40:43,279 Speaker 1: ride them and they'll just go about their business. And 708 00:40:43,520 --> 00:40:46,960 Speaker 1: this is apparently a common occurrence. Um there was a 709 00:40:47,000 --> 00:40:49,600 Speaker 1: common occurrence back in the day. Sometimes they say you 710 00:40:49,600 --> 00:40:52,120 Speaker 1: can get two people on one of these tortoise shells 711 00:40:52,239 --> 00:40:54,319 Speaker 1: and just ride them and they'll do their thing, like 712 00:40:54,960 --> 00:40:57,960 Speaker 1: you know, they don't seem uh, they don't seem bothered. Now, 713 00:40:58,000 --> 00:41:00,280 Speaker 1: I'm sure that puts extra strain on their must holes 714 00:41:00,280 --> 00:41:02,200 Speaker 1: and their energy requirements and all that, so it's not 715 00:41:02,280 --> 00:41:05,319 Speaker 1: like okay to do. But just showing the strength of 716 00:41:05,320 --> 00:41:08,520 Speaker 1: the tortoise and how powerful and huge this animal is 717 00:41:08,840 --> 00:41:10,960 Speaker 1: that it could just continue on its way trying to 718 00:41:11,000 --> 00:41:19,400 Speaker 1: graze with like multiple humans riding on its back. Poor creatures. Uh. Yeah, again, 719 00:41:19,440 --> 00:41:21,960 Speaker 1: do not do not attempt to don't do not get 720 00:41:21,960 --> 00:41:24,799 Speaker 1: close to the tortoises, and do not ride them. Now 721 00:41:24,800 --> 00:41:27,239 Speaker 1: we have a fair amount of variety with the Glaucos 722 00:41:27,320 --> 00:41:31,000 Speaker 1: tortoises that they're all of the genus Chillonitis. And you 723 00:41:31,040 --> 00:41:36,000 Speaker 1: get into some discussion about the different varieties, like the 724 00:41:36,000 --> 00:41:40,200 Speaker 1: exact variety count. Uh. And then we have two that 725 00:41:40,239 --> 00:41:46,239 Speaker 1: are definitely extinct. Uh. There's the Floridana Island subspecies that's 726 00:41:46,239 --> 00:41:48,600 Speaker 1: thought to have been hunted do extinction by I think 727 00:41:48,640 --> 00:41:51,600 Speaker 1: eighteen fifty when Darwin visited. This is up with the 728 00:41:51,600 --> 00:41:56,040 Speaker 1: one we only describe seeing their bones. The Penta Island 729 00:41:56,120 --> 00:42:00,480 Speaker 1: species is extinct, as with the death of Lonesome George, 730 00:42:00,480 --> 00:42:03,239 Speaker 1: who was of course famous for being the last of 731 00:42:03,320 --> 00:42:07,720 Speaker 1: his variety. Um, he died, and that it was seemingly 732 00:42:07,800 --> 00:42:11,000 Speaker 1: it for this variety of tortoise. Yeah, I've read that 733 00:42:11,040 --> 00:42:16,879 Speaker 1: there are either twelve or thirteen extant uh species. Yeah, 734 00:42:23,400 --> 00:42:29,200 Speaker 1: thank thank so. Coming back to the challenges that tortoises 735 00:42:29,560 --> 00:42:33,760 Speaker 1: faced during the age of humans, we've we've they're thoroughly discussed. 736 00:42:33,800 --> 00:42:36,879 Speaker 1: I think the human hunting and human harvesting of tortoises 737 00:42:37,440 --> 00:42:40,000 Speaker 1: at least for our purposes here. Um. But of course 738 00:42:40,040 --> 00:42:44,640 Speaker 1: they are all these invasive species that humans introduced. And 739 00:42:44,800 --> 00:42:48,359 Speaker 1: while we are dealing with cases in some cases where 740 00:42:48,400 --> 00:42:52,319 Speaker 1: you'll have animals directly going after young tortoises, uh, there 741 00:42:52,360 --> 00:42:57,160 Speaker 1: are also other ways that these creatures were harmful and 742 00:42:57,200 --> 00:43:00,000 Speaker 1: are and can still be harmful to the native glacial 743 00:43:00,000 --> 00:43:02,960 Speaker 1: those tortoises. Right. And in fact, one example of this 744 00:43:03,040 --> 00:43:06,200 Speaker 1: came up in some episodes we did back in October 745 00:43:06,239 --> 00:43:09,319 Speaker 1: on goats, right, the the issue of goats competing for 746 00:43:09,360 --> 00:43:13,880 Speaker 1: resources with tortoises. That's right. Again. Goats, as we discussed, 747 00:43:13,920 --> 00:43:18,040 Speaker 1: are amazing at what they do at roaming around finding 748 00:43:18,040 --> 00:43:23,280 Speaker 1: audits of vegetation to consume. And yeah, they're they're ultimately 749 00:43:23,360 --> 00:43:25,920 Speaker 1: better at it than tortoises. They're more thorough than the 750 00:43:25,960 --> 00:43:29,120 Speaker 1: tortoises and uh and and ultimately so thorough that they 751 00:43:29,120 --> 00:43:31,680 Speaker 1: can be even more disruptive to like the h to 752 00:43:31,760 --> 00:43:35,040 Speaker 1: the ground itself, like you know, getting in there and 753 00:43:35,280 --> 00:43:39,840 Speaker 1: actually making it unstable. So that's that's one thing to consider. 754 00:43:39,920 --> 00:43:42,480 Speaker 1: Also when you're dealing with any creature that lays its 755 00:43:42,480 --> 00:43:44,759 Speaker 1: eggs in the ground. Uh, Not only do you have 756 00:43:44,840 --> 00:43:47,920 Speaker 1: to worry with certain species, like especially pigs and rats 757 00:43:47,960 --> 00:43:51,640 Speaker 1: going after those eggs and then going after the young. Potentially, 758 00:43:52,080 --> 00:43:54,640 Speaker 1: you also have to deal with cattle because there are 759 00:43:54,640 --> 00:43:56,880 Speaker 1: are still cattle on the on the islands, and cattle 760 00:43:56,920 --> 00:44:00,160 Speaker 1: were brought to the islands and cattle aren't in us. 761 00:44:00,160 --> 00:44:03,040 Speaker 1: Did in really eating those tortoise eggs, but they will 762 00:44:03,080 --> 00:44:05,279 Speaker 1: definitely step on those tortoise eggs if they happen to 763 00:44:05,280 --> 00:44:08,480 Speaker 1: be ranging in the same area. Now, in the previous episode, 764 00:44:08,480 --> 00:44:13,440 Speaker 1: we talked about some hypotheses about how marine iguanas first 765 00:44:13,560 --> 00:44:17,640 Speaker 1: arrived on the Galapagos Islands, probably via some kind of 766 00:44:17,760 --> 00:44:20,480 Speaker 1: rafting from the mainland. Is that also the idea of 767 00:44:20,520 --> 00:44:25,200 Speaker 1: what likely happened with the ancestral tortoises. That's my understanding 768 00:44:25,200 --> 00:44:27,960 Speaker 1: based on the sources I was looking at, and based 769 00:44:28,120 --> 00:44:32,600 Speaker 1: on conversations with with some of the the naturalist and 770 00:44:32,680 --> 00:44:35,759 Speaker 1: guides in the Glapicos Islands, that the idea is that 771 00:44:35,800 --> 00:44:39,200 Speaker 1: it would have been much the same tortoises in South America, 772 00:44:39,560 --> 00:44:43,879 Speaker 1: swept up in river floods, washed out with vegetation which 773 00:44:43,920 --> 00:44:46,720 Speaker 1: they were able to raft on and uh and reaching 774 00:44:47,320 --> 00:44:50,600 Speaker 1: these far flung islands. So it's amazing to imagine these 775 00:44:51,320 --> 00:44:55,360 Speaker 1: extremely unlikely, kind of one off events that allowed the 776 00:44:55,400 --> 00:44:57,960 Speaker 1: population of each island because it's not something you see 777 00:44:58,000 --> 00:45:01,120 Speaker 1: happening every day. But know, all it takes is a 778 00:45:01,360 --> 00:45:04,800 Speaker 1: is a small seed population to get there and then wow, 779 00:45:04,840 --> 00:45:07,560 Speaker 1: what's this. You know, there's there's all these food resources 780 00:45:07,560 --> 00:45:11,359 Speaker 1: and no predators and you can really boom once you arrive. Yeah. 781 00:45:11,480 --> 00:45:13,480 Speaker 1: And I'm not sure if the numbers on this are 782 00:45:14,160 --> 00:45:19,080 Speaker 1: you know, certified as it were, but it seems like 783 00:45:19,120 --> 00:45:21,719 Speaker 1: the first Glava Coast tortoises probably reached the islands two 784 00:45:21,719 --> 00:45:25,160 Speaker 1: to three million years ago via rafting. Uh. They would 785 00:45:25,160 --> 00:45:28,520 Speaker 1: have probably arrived on the eastern islands of Espanola and 786 00:45:28,840 --> 00:45:33,439 Speaker 1: San Cristobil first and then spread west from there. Uh 787 00:45:33,520 --> 00:45:37,279 Speaker 1: So it's uh, yeah, it's interesting to think about now. 788 00:45:37,320 --> 00:45:39,960 Speaker 1: The the other question that I guess came up from 789 00:45:40,000 --> 00:45:42,400 Speaker 1: me in the in this was like how big were 790 00:45:42,440 --> 00:45:45,960 Speaker 1: these tortoises when they first arrived, Because at least some 791 00:45:46,080 --> 00:45:49,240 Speaker 1: sources out there make the case that they were already 792 00:45:49,320 --> 00:45:53,239 Speaker 1: big and that they were already quote unquote gigantic um. 793 00:45:53,400 --> 00:45:56,080 Speaker 1: While plenty of other sources also discussed glab of Coast 794 00:45:56,120 --> 00:46:01,080 Speaker 1: tortoises as a case of island gigantism. Yeah, so island 795 00:46:01,120 --> 00:46:05,279 Speaker 1: gigantism is uh something that often occurs. There's uh known 796 00:46:05,280 --> 00:46:07,920 Speaker 1: as island dwarf is AM and island gigantism. These kind 797 00:46:07,920 --> 00:46:12,000 Speaker 1: of runaway pressures on the size of animals that can 798 00:46:12,560 --> 00:46:15,680 Speaker 1: that can really bulk them up or shrink them down 799 00:46:15,800 --> 00:46:19,360 Speaker 1: when they're on an in a contained ecosystem like an island. 800 00:46:20,080 --> 00:46:21,880 Speaker 1: And I don't think we know exactly what all the 801 00:46:21,880 --> 00:46:24,239 Speaker 1: pressures would be, but you could imagine something like, well, 802 00:46:24,280 --> 00:46:28,560 Speaker 1: maybe there is always sexual selection on say the size 803 00:46:28,560 --> 00:46:31,160 Speaker 1: of adult male tortoises, to make them bigger and bigger, 804 00:46:31,200 --> 00:46:33,560 Speaker 1: because the bigger you are, the more likely a female 805 00:46:33,640 --> 00:46:36,840 Speaker 1: is to be receptive to mating. So there's sexual selection 806 00:46:36,920 --> 00:46:40,359 Speaker 1: driving them to be bigger. But then there's naturally some 807 00:46:40,440 --> 00:46:44,200 Speaker 1: kind of other pressure that wants to keep their size smaller. 808 00:46:44,280 --> 00:46:47,280 Speaker 1: You know, like you there's that advantage in being bigger, 809 00:46:47,280 --> 00:46:49,880 Speaker 1: but once you're bigger, maybe you're more at risk of predation, 810 00:46:50,080 --> 00:46:53,680 Speaker 1: or it's harder to thermoregulate or something like that. And 811 00:46:53,760 --> 00:46:55,960 Speaker 1: you can imagine cases where you get on an island 812 00:46:56,080 --> 00:46:59,480 Speaker 1: and suddenly those other pressures are relieved and so you 813 00:46:59,480 --> 00:47:01,600 Speaker 1: can just keep getting bigger and bigger than you would 814 00:47:01,600 --> 00:47:05,160 Speaker 1: have been allowed to on the mainland. Yeah, yeah, I guess. 815 00:47:05,160 --> 00:47:07,760 Speaker 1: On the On the on the like supporting the idea 816 00:47:08,200 --> 00:47:11,719 Speaker 1: that they were already big, there is uh. There is, 817 00:47:11,719 --> 00:47:15,360 Speaker 1: of course fossil evidence of of gigantic tortoises existing on 818 00:47:15,440 --> 00:47:20,319 Speaker 1: I think every continent except Australia and Antarctica um at 819 00:47:20,360 --> 00:47:23,359 Speaker 1: some point in the past, so it's not like these 820 00:47:23,400 --> 00:47:28,200 Speaker 1: forms only emerged on on various islands island environments. But 821 00:47:28,200 --> 00:47:29,439 Speaker 1: but I don't know. On the other hand, it seems 822 00:47:29,480 --> 00:47:32,759 Speaker 1: like plenty of sources are discussing this as gigantism. One 823 00:47:32,800 --> 00:47:35,960 Speaker 1: paper I was looking at this is from Jaffee at All, 824 00:47:36,440 --> 00:47:38,319 Speaker 1: from a two thousand and eleven paper in the Royal 825 00:47:38,360 --> 00:47:41,640 Speaker 1: Society Biology Letters, the Evolution of island gigantism and Body 826 00:47:41,719 --> 00:47:46,160 Speaker 1: size Variation in Tortoises and Turtles UM. They point out 827 00:47:46,200 --> 00:47:48,759 Speaker 1: that they do point out that quote the other evolutionary 828 00:47:48,800 --> 00:47:53,080 Speaker 1: determinants of size diversity in Chelonians are protly understood, but 829 00:47:53,520 --> 00:47:56,520 Speaker 1: they also point out that Chelonians spans some four orders 830 00:47:56,560 --> 00:47:59,960 Speaker 1: of magnitude in their sizes, and that there is quote 831 00:48:00,040 --> 00:48:05,480 Speaker 1: a pronounced relationship between habitat and optimal body size. Also 832 00:48:05,520 --> 00:48:08,719 Speaker 1: worth noting that the apparently the closest living relative to 833 00:48:08,760 --> 00:48:14,319 Speaker 1: the Galapacos tortoise is not a direct ancestor of those tortoises, 834 00:48:14,760 --> 00:48:16,960 Speaker 1: but it is a really it is itself a relatively 835 00:48:17,080 --> 00:48:20,680 Speaker 1: small bodied variety of tortoise that's found in South America, 836 00:48:21,920 --> 00:48:24,560 Speaker 1: the Chaco tortoise, I believe it is called now. I 837 00:48:24,560 --> 00:48:27,239 Speaker 1: also mentioned that there there are other giant tortoises still 838 00:48:27,280 --> 00:48:29,919 Speaker 1: in the world outside of the Glapacos. Uh. These would 839 00:48:29,920 --> 00:48:34,400 Speaker 1: be giant tortoises that survived in the Western Indian Ocean 840 00:48:34,800 --> 00:48:38,120 Speaker 1: in the form of aldabra giant tortoises. Yeah. And I 841 00:48:38,160 --> 00:48:41,359 Speaker 1: believe when Darwin arrived he thought that these were the 842 00:48:41,480 --> 00:48:44,200 Speaker 1: same species, like that the ones on the Galapacos were 843 00:48:44,200 --> 00:48:47,319 Speaker 1: the same as those, or at least the same as 844 00:48:47,400 --> 00:48:49,960 Speaker 1: some other island gigantic tortoise he was aware of. I 845 00:48:50,000 --> 00:48:51,560 Speaker 1: think it would have been those, because those are the 846 00:48:51,600 --> 00:48:54,600 Speaker 1: only other ones I know of. Um, and he he 847 00:48:54,680 --> 00:48:57,480 Speaker 1: was mistaken in that, in fact that they're just uh, 848 00:48:57,640 --> 00:49:02,640 Speaker 1: they're different parallel forms of of gigantic tortoises. But one 849 00:49:02,880 --> 00:49:04,960 Speaker 1: last thing I wanted to talk about with these tortoises 850 00:49:05,000 --> 00:49:08,680 Speaker 1: before we we wrap up today is the differences in 851 00:49:08,719 --> 00:49:13,120 Speaker 1: the shell shapes, because we mentioned earlier that some species 852 00:49:13,200 --> 00:49:17,040 Speaker 1: have more dome shaped shells and some have these saddle 853 00:49:17,120 --> 00:49:21,160 Speaker 1: shaped shells, and there are also intermediate species that have 854 00:49:21,800 --> 00:49:25,160 Speaker 1: sort of somewhere in between. UH. Creature and Laughlin have 855 00:49:25,200 --> 00:49:28,000 Speaker 1: a great section on this in their chapter on the tortoises, 856 00:49:28,040 --> 00:49:29,920 Speaker 1: and UH and I wanted to talk about it a bit. 857 00:49:29,960 --> 00:49:33,839 Speaker 1: So one of the questions is why, uh, you can 858 00:49:33,880 --> 00:49:38,640 Speaker 1: observe some things that might lead to these differences. The 859 00:49:38,680 --> 00:49:41,600 Speaker 1: tortoises with the domed shells tend to live more in 860 00:49:41,640 --> 00:49:45,200 Speaker 1: the highlands and around calledera rims, where vegetation is much 861 00:49:45,200 --> 00:49:50,200 Speaker 1: thicker and lush all the time, whereas the ones with 862 00:49:50,239 --> 00:49:53,279 Speaker 1: the saddle backed shells tend to live more or even 863 00:49:53,280 --> 00:49:58,000 Speaker 1: exclusively in the lowlands, where conditions are more often dry. 864 00:49:58,360 --> 00:50:01,040 Speaker 1: Of course, the differences in these shell is that, well, 865 00:50:01,080 --> 00:50:02,880 Speaker 1: as the domed ones are more just kind of like 866 00:50:02,920 --> 00:50:06,880 Speaker 1: an upturned cup over the over the reptiles back the 867 00:50:06,960 --> 00:50:10,400 Speaker 1: saddle back tortoises, their shell tends to have like a 868 00:50:10,800 --> 00:50:13,960 Speaker 1: relief area above the head and neck. It's almost like 869 00:50:14,000 --> 00:50:17,520 Speaker 1: a like a collar that's pulled back. And there are 870 00:50:17,560 --> 00:50:20,120 Speaker 1: some other differences to the domed tortoises tend to have 871 00:50:20,160 --> 00:50:24,400 Speaker 1: a larger body size but shorter legs and necks, whereas 872 00:50:24,440 --> 00:50:27,759 Speaker 1: the saddle back tortoises tend to be smaller overall but 873 00:50:27,880 --> 00:50:31,640 Speaker 1: have longer legs and longer necks. Now, I remember in 874 00:50:31,680 --> 00:50:34,719 Speaker 1: the last episode when we talked about the marine iguanas, 875 00:50:34,760 --> 00:50:38,400 Speaker 1: and we were trying to come up with the the 876 00:50:38,440 --> 00:50:42,840 Speaker 1: biological explanation for why the iguana kept returning out of 877 00:50:42,880 --> 00:50:45,640 Speaker 1: the water after Darwin threw it in, even though you 878 00:50:45,680 --> 00:50:47,080 Speaker 1: know it's got to go in the water all the 879 00:50:47,120 --> 00:50:49,719 Speaker 1: time to to eat, So why doesn't it just stay 880 00:50:49,760 --> 00:50:52,600 Speaker 1: in the water to stay away from him? Uh? And 881 00:50:52,840 --> 00:50:55,200 Speaker 1: the answer we came up with that the Darwin did 882 00:50:55,200 --> 00:50:59,960 Speaker 1: not land on himself is that is probably for thermoregulation 883 00:51:00,040 --> 00:51:02,840 Speaker 1: and reasons because the water is cold and it was 884 00:51:02,880 --> 00:51:06,120 Speaker 1: removing heat from the iguana's body, and the iguana needs 885 00:51:06,160 --> 00:51:08,319 Speaker 1: to get back up on land to heat back up. 886 00:51:09,120 --> 00:51:13,799 Speaker 1: I think a good explanation for one of the explanations 887 00:51:13,800 --> 00:51:17,240 Speaker 1: for the different body plans of these different tortoises probably 888 00:51:17,320 --> 00:51:21,880 Speaker 1: also has to do with reptile thermoregulation with the the 889 00:51:21,920 --> 00:51:26,879 Speaker 1: regulation of body temperature, because of course, animals with a 890 00:51:27,000 --> 00:51:32,280 Speaker 1: larger body volume also tend to retain more heat because 891 00:51:32,440 --> 00:51:36,759 Speaker 1: they have less surface area proportional to their volume. So 892 00:51:36,800 --> 00:51:39,279 Speaker 1: if you're living in a cold place and you're trying 893 00:51:39,320 --> 00:51:42,279 Speaker 1: to retain body heat, it's easier to do that if 894 00:51:42,320 --> 00:51:45,320 Speaker 1: you're bigger. You've got there's just more body in there 895 00:51:45,480 --> 00:51:49,399 Speaker 1: and less relatively less surface area, and vice versa. It's 896 00:51:49,400 --> 00:51:52,600 Speaker 1: easier to cool off if you're smaller because a bigger 897 00:51:52,680 --> 00:51:55,640 Speaker 1: percent of your body is surface area that you can 898 00:51:55,680 --> 00:51:59,239 Speaker 1: lose heat through. This would seem to correlate with the 899 00:51:59,320 --> 00:52:02,759 Speaker 1: observation and that the domed tortoises, which live up in 900 00:52:02,800 --> 00:52:05,280 Speaker 1: the highlands where it tends to be a little bit cooler, 901 00:52:05,600 --> 00:52:08,720 Speaker 1: tend to have a larger body size, but also shorter 902 00:52:08,920 --> 00:52:12,279 Speaker 1: legs and necks, so less extremities poke poking out that 903 00:52:12,400 --> 00:52:16,080 Speaker 1: can lose heat, whereas these saddleback tortoises tend to be 904 00:52:16,160 --> 00:52:20,000 Speaker 1: smaller overall, with longer legs and longer necks, and they 905 00:52:20,000 --> 00:52:24,839 Speaker 1: live down in the lowlands where things tend to be hotter. Yeah, yeah, now, 906 00:52:24,880 --> 00:52:26,920 Speaker 1: most of the tortoises I got to observe. We're definitely 907 00:52:26,960 --> 00:52:32,960 Speaker 1: in highland environments. But uh, yeah, their their relationship with 908 00:52:32,960 --> 00:52:36,160 Speaker 1: temperature is is notable as well. Uh. In one case, 909 00:52:36,320 --> 00:52:37,719 Speaker 1: you know, we've got to go out and see these 910 00:52:37,760 --> 00:52:41,960 Speaker 1: tortoises out there in this um uh this this uh 911 00:52:42,080 --> 00:52:44,880 Speaker 1: this highland area, and it was early enough in the 912 00:52:44,960 --> 00:52:47,080 Speaker 1: day that some of them were essentially sleeping in. They 913 00:52:47,080 --> 00:52:50,360 Speaker 1: were still bedded down in the mud where they could 914 00:52:50,680 --> 00:52:53,320 Speaker 1: they could, you know, keep their temperature relatively stable throughout 915 00:52:53,360 --> 00:52:55,719 Speaker 1: the night. And some were already getting up to begin 916 00:52:55,760 --> 00:52:59,719 Speaker 1: their their day of eating. Others just weren't quite ready yet. 917 00:53:00,239 --> 00:53:02,719 Speaker 1: Oh yeah. And I've read that these tortoises just love 918 00:53:02,800 --> 00:53:05,560 Speaker 1: the mud, like they love to get in the mud puddles, 919 00:53:05,560 --> 00:53:08,520 Speaker 1: and they'll just hang out there for days sometimes. Yeah, 920 00:53:08,560 --> 00:53:10,319 Speaker 1: so that you'll see them trooping around, and you on 921 00:53:10,320 --> 00:53:12,360 Speaker 1: one level, they kind of look like bulldozers because it 922 00:53:12,480 --> 00:53:15,279 Speaker 1: just covered with mud, and of course they've been eating too. 923 00:53:15,520 --> 00:53:17,440 Speaker 1: There are lots of pictures you included one here of 924 00:53:17,520 --> 00:53:21,239 Speaker 1: one with just this spectacularly messy face from all the 925 00:53:21,840 --> 00:53:25,200 Speaker 1: vegetation and or fruits it's been consumed. It's just smeared 926 00:53:25,239 --> 00:53:28,200 Speaker 1: all over. It's like one of those gross baby pictures 927 00:53:28,200 --> 00:53:30,800 Speaker 1: where the baby just they've been faced down in a 928 00:53:30,880 --> 00:53:34,200 Speaker 1: plate of spaghetti. Yeah, and their face, the face of 929 00:53:34,239 --> 00:53:37,080 Speaker 1: the the Glabcoast tortoise does kind of look like like 930 00:53:37,360 --> 00:53:41,240 Speaker 1: old baby. Um, so it really matches up with that well. 931 00:53:41,800 --> 00:53:45,600 Speaker 1: But there are other differences in the environments that might 932 00:53:45,680 --> 00:53:50,320 Speaker 1: explain the different body plans of these tortoise species. So uh, 933 00:53:50,360 --> 00:53:52,879 Speaker 1: A lot of it probably has to do with vegetation, right. 934 00:53:53,280 --> 00:53:56,680 Speaker 1: Domed tortoises tend to live in more lush highlands with 935 00:53:56,840 --> 00:54:01,400 Speaker 1: dense undergrowth, and uh a creature and offline right quote. 936 00:54:01,520 --> 00:54:05,040 Speaker 1: The domed shells, smoothly rounded as they are, may prove 937 00:54:05,080 --> 00:54:09,879 Speaker 1: adaptive as the tortoises move tank like through dense plant cover, 938 00:54:10,040 --> 00:54:13,279 Speaker 1: which is of course also the animal's food source. On 939 00:54:13,320 --> 00:54:16,640 Speaker 1: the other hand, saddle type shells with a large forward 940 00:54:16,760 --> 00:54:21,319 Speaker 1: notch can actually become snagged in low vegetation, impeding the 941 00:54:21,360 --> 00:54:24,880 Speaker 1: movement of the tortoise. Saddle shells are not very adaptive 942 00:54:24,920 --> 00:54:27,759 Speaker 1: in low dense vegetation, so it's just going to be 943 00:54:27,800 --> 00:54:31,560 Speaker 1: easier to move around with a more rounded shell uh. 944 00:54:31,600 --> 00:54:33,920 Speaker 1: In in all that thick brush in the in the 945 00:54:34,000 --> 00:54:37,080 Speaker 1: upper highland forest regions, whereas if you had the saddle 946 00:54:37,080 --> 00:54:39,360 Speaker 1: shell with the you know, the upturned sort of collar 947 00:54:39,400 --> 00:54:41,160 Speaker 1: in the front. Yeah, that just be getting hooked on 948 00:54:41,200 --> 00:54:44,000 Speaker 1: stuff all the time. And I mean they are little bulldozers. 949 00:54:44,000 --> 00:54:47,440 Speaker 1: They can tear stuff up, like for instance, Uh, you know, 950 00:54:47,719 --> 00:54:51,120 Speaker 1: they're gonna be limits. They could continue to be be 951 00:54:51,160 --> 00:54:54,120 Speaker 1: slowed down or I guess stuck in vegetation. But uh, 952 00:54:54,560 --> 00:54:56,640 Speaker 1: to give one example that I was told about, do 953 00:54:56,680 --> 00:55:00,680 Speaker 1: you have again individuals who are still ranching in these 954 00:55:00,840 --> 00:55:03,319 Speaker 1: in these parts of the highland, they have cows. Um, 955 00:55:03,480 --> 00:55:07,040 Speaker 1: they need to contain those cows. But if they're gonna 956 00:55:07,040 --> 00:55:10,160 Speaker 1: be tortoises moving through, they're gonna they're just gonna take 957 00:55:10,200 --> 00:55:13,200 Speaker 1: down your barbed wire fence or your your whatever kind 958 00:55:13,200 --> 00:55:16,279 Speaker 1: of fencing you have. So in many cases they'll have 959 00:55:16,320 --> 00:55:18,760 Speaker 1: the fencing, they'll have this big gap at the bottom 960 00:55:18,920 --> 00:55:21,000 Speaker 1: that will allow a tortoise to move through because that 961 00:55:21,000 --> 00:55:23,000 Speaker 1: way you still get to have your fence and the 962 00:55:23,040 --> 00:55:25,080 Speaker 1: tortoise won't won't tear it down when it makes a 963 00:55:25,120 --> 00:55:28,800 Speaker 1: bee line for whatever wherever it's going. Unfortunately, the cows 964 00:55:28,840 --> 00:55:33,080 Speaker 1: can't crawl under yeah, I guess not. It did raise 965 00:55:33,160 --> 00:55:34,919 Speaker 1: some questions like well can they Yeah, can the cow 966 00:55:35,719 --> 00:55:38,360 Speaker 1: what about really short cows? I don't know, but apparently 967 00:55:38,360 --> 00:55:41,440 Speaker 1: it works. But the final thing with the difference between 968 00:55:41,480 --> 00:55:45,120 Speaker 1: the domed tortoises and the saddlebacks is probably food sources 969 00:55:45,200 --> 00:55:48,719 Speaker 1: as well, because again, the domed ones are going to 970 00:55:48,760 --> 00:55:51,759 Speaker 1: be munching on a lot of you know, lush, low 971 00:55:51,840 --> 00:55:55,600 Speaker 1: lying vegetation. Uh so you know that that that's just 972 00:55:55,920 --> 00:55:58,800 Speaker 1: that's okay to have a normal kind of dome dome 973 00:55:58,880 --> 00:56:03,200 Speaker 1: shaped shell for that. But the saddleback tortoises, which live 974 00:56:03,239 --> 00:56:07,920 Speaker 1: in the more arid lowlands, are going to be eating cacti, 975 00:56:08,280 --> 00:56:11,520 Speaker 1: often tall cacti that they need to reach up to 976 00:56:11,600 --> 00:56:14,959 Speaker 1: get to, and so the upturned front of the shell 977 00:56:15,080 --> 00:56:17,880 Speaker 1: allows more room to raise the neck, and of course, 978 00:56:17,920 --> 00:56:19,840 Speaker 1: of course, as I said as well, they've got longer 979 00:56:19,920 --> 00:56:23,239 Speaker 1: necks and longer legs to help reach. Robin, I think 980 00:56:23,280 --> 00:56:27,160 Speaker 1: you said you observe stuff about those cactuses sort of 981 00:56:27,239 --> 00:56:30,080 Speaker 1: reacting to that by growing taller and taller to try 982 00:56:30,120 --> 00:56:34,600 Speaker 1: to escape the munching tortoises. Yeah. Yeah, And it's it's 983 00:56:34,600 --> 00:56:37,880 Speaker 1: remarkable to see because yeah, here's this um, here's this 984 00:56:37,960 --> 00:56:42,120 Speaker 1: cactus that has evolved thrive alongside the tortoises and it 985 00:56:42,200 --> 00:56:43,840 Speaker 1: ends up Yeah, it ends up feeling more like a 986 00:56:43,880 --> 00:56:47,359 Speaker 1: tree than a cactus, if that makes sense. Um, yeah, 987 00:56:47,600 --> 00:56:51,480 Speaker 1: it's a remarkable ecosystem. All right, So there you have it. 988 00:56:51,640 --> 00:56:54,759 Speaker 1: Hopefully we gave just at least a nice snapshot, a 989 00:56:54,880 --> 00:56:59,399 Speaker 1: nice overview of the Galapgos tortoise. Uh. There. Obviously there's 990 00:56:59,400 --> 00:57:02,120 Speaker 1: a lot of search out there about these creatures, so 991 00:57:02,760 --> 00:57:05,840 Speaker 1: perhaps there's there are some details that we managed to 992 00:57:05,920 --> 00:57:08,000 Speaker 1: leave out. If you think that we left out something 993 00:57:08,000 --> 00:57:11,000 Speaker 1: that is particularly exciting, then right in. We'd love to 994 00:57:11,000 --> 00:57:12,720 Speaker 1: hear about it. We'd love to see it for ourselves 995 00:57:12,760 --> 00:57:15,560 Speaker 1: and to share it in a future listener mail. Likewise, 996 00:57:15,560 --> 00:57:17,680 Speaker 1: as I mentioned the first one, if you've traveled to 997 00:57:17,720 --> 00:57:20,680 Speaker 1: the Labcost Islands, if you if you live on the 998 00:57:20,720 --> 00:57:25,200 Speaker 1: Galabicost Islands or or are an Ecuadorian, we would also 999 00:57:25,240 --> 00:57:27,400 Speaker 1: love to hear from you. We love your thoughts on 1000 00:57:28,040 --> 00:57:30,520 Speaker 1: these fabulous creatures that we've discussed here, or any of 1001 00:57:30,520 --> 00:57:34,000 Speaker 1: the other creatures of the Glabgost Islands. I'm always excited 1002 00:57:34,040 --> 00:57:37,120 Speaker 1: to hear more. Just a reminder to everybody that that's 1003 00:57:37,120 --> 00:57:39,600 Speaker 1: stuff to blow your mind. Publishes its core episodes on 1004 00:57:39,640 --> 00:57:41,840 Speaker 1: Tuesdays and Thursdays and the Stuff to Blow Your Mind 1005 00:57:41,840 --> 00:57:45,480 Speaker 1: podcast feed We have booster mail episodes on Mondays, a 1006 00:57:45,560 --> 00:57:49,200 Speaker 1: short form artifact or monster fact episode on Wednesdays, and 1007 00:57:49,200 --> 00:57:51,960 Speaker 1: on Fridays we set aside most serious concerns and just 1008 00:57:52,040 --> 00:57:56,040 Speaker 1: talk about a weird film. Huge thanks to our audio producer, 1009 00:57:56,240 --> 00:57:58,960 Speaker 1: Max Williams. 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