WEBVTT - The Saguaro, Part 2 0:00:03.040 --> 0:00:06.760 Welcome to Stuff to Blow Your Mind production of iHeartRadio. 0:00:13.080 --> 0:00:14.920 Hey you welcome to Stuff to Blow Your Mind. My 0:00:15.000 --> 0:00:16.160 name is Robert Lamb. 0:00:16.320 --> 0:00:18.840 And I'm Joe McCormick, and we're back with part two 0:00:19.000 --> 0:00:23.720 in our series about the sowarrow cactus of the Sonoran Desert. 0:00:24.160 --> 0:00:27.080 If you're not very familiar with different cactus species, but 0:00:27.120 --> 0:00:30.960 you've seen a few old Hollywood westerns, or if you've 0:00:31.040 --> 0:00:33.519 just I don't know, looked at picture books made for 0:00:33.600 --> 0:00:37.199 kids or cartoons or something, you will probably recognize the 0:00:37.320 --> 0:00:42.160 ciwaro as the plant icon of the American Southwest. It's 0:00:42.200 --> 0:00:45.920 got this large, round, vertical stem, kind of like a 0:00:45.960 --> 0:00:49.000 tree trunk, and then these limbs that branch out from 0:00:49.000 --> 0:00:52.760 the core when the cactus is mature. We were talking 0:00:52.800 --> 0:00:55.840 in the last episode about how the sowarro is probably 0:00:56.000 --> 0:00:58.639 just what a lot of people think of when they 0:00:58.680 --> 0:01:03.160 think cactus, despite the fact that its geographic range is 0:01:03.440 --> 0:01:06.760 somewhat limited compared to more widely distributed species like the 0:01:06.760 --> 0:01:12.160 prickly pair. But it's just a fundamentally very charismatic plant. 0:01:12.760 --> 0:01:15.680 And the last time we talked about some reasons why 0:01:15.720 --> 0:01:18.959 that might be. It's sort of human shaped, you know, 0:01:19.040 --> 0:01:20.959 it's got a trunk kind of like a human maybe 0:01:20.959 --> 0:01:24.840 with arms looking raised in a posture that's kind of friendly. 0:01:26.720 --> 0:01:29.039 So in the last episode we talked about that. We 0:01:29.120 --> 0:01:32.759 also just generally introduced and described the species. We talked 0:01:32.760 --> 0:01:35.800 about the origin of its scientific name and the tie 0:01:35.840 --> 0:01:39.760 into Andrew Carnegie. We got a bit into its evolution 0:01:40.000 --> 0:01:43.520 and some interesting features like its rib structure and its spines. 0:01:43.880 --> 0:01:46.279 And so we're back today to talk some more about 0:01:46.319 --> 0:01:50.360 the sorrow and should we do a pronunciation note people 0:01:50.400 --> 0:01:54.640 pronounce this word different ways. We have landed on sowarrow, 0:01:55.160 --> 0:01:56.560 but there are other options. 0:01:56.560 --> 0:02:00.480 Apparently, Yeah, sowarrow is what the National Park Service says, 0:02:01.000 --> 0:02:04.320 so we're going with that. But like you look up 0:02:04.400 --> 0:02:08.440 souarrow in webster as, you'll find two different pronunciations for it. 0:02:09.240 --> 0:02:12.120 So if you have one that you prefer, if you 0:02:12.160 --> 0:02:15.800 think we're in the wrong here right in, we'll hash 0:02:15.840 --> 0:02:16.919 it out in listener mail. 0:02:17.280 --> 0:02:20.960 Sure, which probably also mentioned at the top, because we 0:02:21.360 --> 0:02:23.840 rob in the last episode you were reading from this book, 0:02:23.840 --> 0:02:26.400 but actually in the meantime I started reading it as well, 0:02:26.480 --> 0:02:28.919 so we're both using as a major source for these 0:02:28.960 --> 0:02:33.000 episodes a book called The The Well I did it 0:02:33.000 --> 0:02:36.079 there with the har g I started to Saguaro the 0:02:36.360 --> 0:02:41.120 Sowaro Cactus, a Natural History from University of Arizona Press, 0:02:41.200 --> 0:02:45.680 twenty twenty that is by a group of researchers and 0:02:45.720 --> 0:02:50.600 scholars named David Yetman, Alberto Burquz, Kevin Holteen, and Michael Sanderson. 0:02:51.280 --> 0:02:54.120 Yeah. So we'll refer back to that multiple times. But 0:02:54.360 --> 0:02:57.240 it's an easy book to pick up. It's available wherever 0:02:57.280 --> 0:03:01.160 you get your books, and it is a great deal 0:03:01.200 --> 0:03:03.280 more depth. So if you if you really want to 0:03:03.320 --> 0:03:06.359 dive into the world of the Suaro, it's a it's 0:03:06.360 --> 0:03:07.120 a great text to have. 0:03:07.520 --> 0:03:10.160 Now, Robert, I can't believe I didn't ask you this 0:03:10.320 --> 0:03:13.360 in the last episode, or I hope I'm not repeating myself. 0:03:13.360 --> 0:03:17.280 I think I didn't. We're talking about the suarrow because 0:03:17.320 --> 0:03:20.200 you were recently in Arizona. So I assume you were 0:03:20.200 --> 0:03:23.639 in the region of the Sonoran Desert, and so did 0:03:23.639 --> 0:03:25.880 you get close to these things while you were out there? 0:03:26.000 --> 0:03:28.760 Oh? Yeah, it's like you you really can't help but 0:03:28.880 --> 0:03:31.840 do so, Like like I said, for example, you land 0:03:31.840 --> 0:03:35.400 in Phoenix and you leave the Sky Harbor Airport there, 0:03:35.880 --> 0:03:37.560 you're just going to see them everywhere. And if you 0:03:37.640 --> 0:03:41.120 do any amount of hiking within their range, which we 0:03:41.200 --> 0:03:44.320 always try and do. Yeah, you're going to encounter them. 0:03:44.360 --> 0:03:46.680 You're going to encounter big ones, little ones. You're going 0:03:46.720 --> 0:03:49.200 to see the tiny baby suarros. You're going to see 0:03:49.200 --> 0:03:53.280 the giants, You're going to see the ribs, the skeletons. Everything. 0:03:53.840 --> 0:03:55.880 Well, later in this episode, I've got some stuff I 0:03:55.920 --> 0:03:58.560 want to talk about concerning their life cycle and abundance. 0:03:58.600 --> 0:04:01.360 So I hope maybe you can add some uh, some 0:04:01.400 --> 0:04:05.840 commentary from recent firsthand experience, like what ways you see 0:04:05.880 --> 0:04:07.480 these things in their environment? 0:04:08.440 --> 0:04:11.440 Yeah, yeah, it'll be interesting to reflect on that because 0:04:11.480 --> 0:04:14.560 they're you know, they're they're everywhere, so you find yourselves 0:04:15.520 --> 0:04:17.560 as you're walking you you kind of take them for 0:04:17.600 --> 0:04:19.599 granted at times. I mean, you can't see the forest 0:04:19.600 --> 0:04:22.760 for the trees, right and then this this is the forest. Uh. 0:04:23.200 --> 0:04:27.400 But then yeah, they do kind of hypnotize you as 0:04:27.400 --> 0:04:30.560 well at times, and you you can see the human 0:04:30.640 --> 0:04:32.800 form in them. You can see you know, you see 0:04:32.800 --> 0:04:35.120 those ribs, and you start thinking of them as a 0:04:36.000 --> 0:04:38.760 as a living thing, and so they they still cast 0:04:38.800 --> 0:04:40.840 their spell over you even as you sort of get 0:04:40.920 --> 0:04:41.880 used to them being there. 0:04:42.120 --> 0:04:44.799 Do they make sounds do they creak like trees? 0:04:45.520 --> 0:04:50.360 I don't remember any creaking. No, but but but maybe 0:04:50.360 --> 0:04:53.000 I just didn't hear it. We certainly wasn't out there 0:04:53.040 --> 0:04:56.760 in any degree of wind, as I recall. All right, well, 0:04:57.160 --> 0:05:01.680 I want to pick up talking about the relationship between 0:05:02.120 --> 0:05:07.240 the sorrow and rain. So summer moisture from summer rains 0:05:07.320 --> 0:05:10.320 is vital to the sorrow in the form of late 0:05:10.320 --> 0:05:14.560 summer or fall monsoon season rainfalls in the Sonoran Desert. 0:05:14.920 --> 0:05:18.600 And we've already referenced their particular temperature requirements as well, 0:05:18.640 --> 0:05:22.279 like they have a part of their whole range issue 0:05:22.440 --> 0:05:26.520 is they can sustain certain amounts of freezing temperatures, but 0:05:27.480 --> 0:05:31.440 only a certain amount. And it's kind of like, you know, 0:05:31.440 --> 0:05:35.160 a few different factors what they can physically handle themselves, 0:05:35.200 --> 0:05:38.560 and then also the sort of power ups they get 0:05:38.600 --> 0:05:39.560 from their environment. 0:05:39.960 --> 0:05:44.240 Yeah, and being in the desert, you know, they're vulnerable 0:05:44.320 --> 0:05:48.600 to temperature fluctuations on both ends, like getting roasted and 0:05:48.680 --> 0:05:52.840 desiccated by the hot sun in hot weather and also 0:05:53.279 --> 0:05:56.279 suffering freezes, especially in the northern part of their range, 0:05:56.320 --> 0:05:59.520 so they have to protect against they're fighting two fronts there. 0:06:00.040 --> 0:06:03.880 Yeah, so their flowering period evolved to take advantage of 0:06:04.520 --> 0:06:09.200 this particular need for summer moisture, they flower ahead of 0:06:09.240 --> 0:06:12.200 the monsoon rains, giving plenty of time for their fruit 0:06:12.279 --> 0:06:15.760 to develop and seeds to be distributed in time for 0:06:15.800 --> 0:06:19.280 the deluge. Their flowers are pretty big, so eight to 0:06:19.320 --> 0:06:22.080 ten centimeters, are three to four inches in diameter and 0:06:22.200 --> 0:06:25.719 white in color. And here's where it gets really interesting. 0:06:25.800 --> 0:06:30.000 They open at night, generally after ten pm. And remember 0:06:30.040 --> 0:06:32.840 we're mostly talking about Arizona here, just a slim range 0:06:33.240 --> 0:06:37.120 in California. Arizona doesn't observe daylight saving time, so that 0:06:37.200 --> 0:06:39.120 ten pm is going to be pretty consistent as far 0:06:39.160 --> 0:06:40.240 as clock time goes. 0:06:41.440 --> 0:06:44.440 Regarding the flowers, I actually read this on a USDA 0:06:44.760 --> 0:06:48.360 National Plant Data Center sheet. It's just a fact sheet 0:06:48.360 --> 0:06:52.960 about soorows that mention the nocturnal flowers smell like ripe melons. 0:06:53.680 --> 0:06:57.239 Though that did make me imagine, like, wait, who's climbing 0:06:57.360 --> 0:06:59.279 up to get up there and smell the flowers? 0:07:00.000 --> 0:07:02.800 Its parallels, Well, you got to do your research. You 0:07:02.800 --> 0:07:05.240 got to get the step ladder out and smell those flowers. 0:07:05.400 --> 0:07:08.320 Yeah, right, so spines. 0:07:08.400 --> 0:07:14.000 So they open up at night? Why night, you might ask, Well, evolutionarily, 0:07:14.760 --> 0:07:20.320 the Suarro's flower game is aimed at nocturnal pollinators in 0:07:20.360 --> 0:07:23.520 the form of bats, such as the nectar feeding lesser 0:07:23.880 --> 0:07:26.280 long nosed bat. I included a picture of this guy 0:07:26.320 --> 0:07:31.600 for you here has a particular Beavis look. Yeah, I 0:07:31.600 --> 0:07:32.600 think you'll find. 0:07:32.440 --> 0:07:35.160 I like that you included a Beavis for reference. But yeah, 0:07:35.720 --> 0:07:37.960 it even it looks a little It's kind of blonde 0:07:38.000 --> 0:07:41.360 like Beavis, but has the Beavis jaw and nose situation. 0:07:41.800 --> 0:07:43.920 Yeah, you'd think that I watched Beavis and butthead all 0:07:43.960 --> 0:07:46.880 the time since I referenced Beavis in the last episode. 0:07:46.920 --> 0:07:49.920 But I haven't actually watched this show in decades. But 0:07:50.840 --> 0:07:54.480 it's a classic. It's a classic, great show. And yes, 0:07:54.520 --> 0:07:56.400 the bat kind of looks like Beavis. And then you 0:07:56.440 --> 0:08:01.800 also have moth pollinators such as hawk moths, so nocturnal 0:08:01.840 --> 0:08:06.720 pollination is key to the evolution of their flowers. However, 0:08:07.280 --> 0:08:10.160 while the flowers open at night, they're still visited during 0:08:10.160 --> 0:08:13.840 the day by daytime pollinators like various bees, and this 0:08:13.920 --> 0:08:18.400 includes indigenous bees and bees that have been introduced, migratory 0:08:18.520 --> 0:08:23.720 white winged doves and the doves and bees in general. 0:08:24.480 --> 0:08:28.840 These two daytime pollinator sources are actually the most successful 0:08:28.920 --> 0:08:34.560 pollinators among the most northern northern of the Souaros, and 0:08:34.679 --> 0:08:38.120 according to the authors of that University of Arizona book 0:08:38.160 --> 0:08:40.720 that we reference, the reason for this is that most 0:08:40.720 --> 0:08:45.160 of the far northern Saros grow beyond the range of 0:08:45.240 --> 0:08:48.920 pollinating bats, and they're only able to survive it all 0:08:49.000 --> 0:08:53.120 up there, most likely due to the bees. So they've 0:08:53.160 --> 0:08:55.920 kind of pushed beyond the range of the pollinators they 0:08:55.920 --> 0:08:58.120 evolve to depend upon, or at least that's the way 0:08:58.160 --> 0:09:01.160 it's shaken out over time. But the bees are keeping 0:09:01.200 --> 0:09:01.880 them going. 0:09:01.960 --> 0:09:05.600 So they have left their beloved beavis spat behind and 0:09:05.679 --> 0:09:06.760 moved on to the bees. 0:09:06.920 --> 0:09:10.199 Yeah, yeah, yeah. The authors point out that the northern 0:09:10.280 --> 0:09:16.120 Souaros likely exhibit decreased genetic diversity due to this, since 0:09:16.160 --> 0:09:18.920 bees and doves have far more limited ranges compared to 0:09:18.960 --> 0:09:23.320 the bats that might travel sixty miles while foraging during 0:09:23.360 --> 0:09:28.359 their own northward migration. Now, beyond these pollinators the seedlings, 0:09:28.400 --> 0:09:31.559 fruit and seeds of the suaro, which are quite small. 0:09:31.559 --> 0:09:33.200 I don't know if we've described the seeds yet, but 0:09:33.400 --> 0:09:37.160 they're very small. They're important for a whole host of organisms, 0:09:37.559 --> 0:09:42.559 various ant and rodent species depend on the seeds. I 0:09:42.600 --> 0:09:44.000 don't know if we'll get into it in this episode 0:09:44.040 --> 0:09:46.720 or it'll be a subsequent episode, but humans, of course 0:09:47.440 --> 0:09:49.480 make use of the fruit. We'll come back to that. 0:09:50.360 --> 0:09:52.880 Termites will invade the plant to consume some of the 0:09:52.880 --> 0:09:57.400 soft tissues, but apparently never healthy plant tissue. There's a 0:09:57.480 --> 0:10:00.360 nineteen seventy seven study that the authors referred to here 0:10:00.360 --> 0:10:03.680 by Steinberg and Low, and in it it was revealed 0:10:03.880 --> 0:10:08.280 that the average sorrow produces some forty million seeds in 0:10:08.320 --> 0:10:11.320 a lifetime. Few of these seeds. Very few of these 0:10:11.320 --> 0:10:13.960 seeds will survive long enough to germinate, and of those 0:10:14.000 --> 0:10:18.240 that do germinate, as few as one individual plant per 0:10:18.400 --> 0:10:22.520 parent plant will survive the first year, which is pretty 0:10:22.679 --> 0:10:26.559 pretty incredible. This despite a ninety percent germination rate given 0:10:26.640 --> 0:10:29.920 ideal conditions. There's just that much out there looking to 0:10:29.960 --> 0:10:33.600 eat the seeds, the fruit, or the sprout itself before 0:10:33.640 --> 0:10:37.319 it gets past that one year point and one year old, 0:10:37.440 --> 0:10:41.480 soorrows are still tiny. I encourage folks to look up 0:10:41.520 --> 0:10:44.840 pictures of these. They If you've ever been to certain beaches, 0:10:44.880 --> 0:10:50.400 you may have encounted sand spurs, these little little little 0:10:50.480 --> 0:10:54.120 prickly bets with tiny spines on them. That's about what 0:10:54.520 --> 0:10:57.200 a baby, a one year old sorrow looks like. 0:10:57.600 --> 0:11:00.920 Yeah, those things are the bane of dull being walked 0:11:01.000 --> 0:11:01.559 near the beach. 0:11:01.679 --> 0:11:04.480 But yeah, they're so tiny, but yet they will become 0:11:04.920 --> 0:11:11.160 in time and given given that the correct role of luck, 0:11:11.200 --> 0:11:12.280 they will become giants. 0:11:12.559 --> 0:11:16.520 Yeah. Well, I guess that feeds right into something I 0:11:16.559 --> 0:11:19.120 wanted to talk about, which is the is the broader 0:11:19.200 --> 0:11:25.560 picture of how slowly Soorrows grow. And you're exactly right 0:11:25.720 --> 0:11:32.040 that the earliest stages of growth are the most excruciatingly slow. 0:11:33.000 --> 0:11:36.920 So studies carried out in Sorrow National Park indicate that 0:11:38.000 --> 0:11:41.760 a sorrow seedling, after it germinates, on average, takes about 0:11:41.880 --> 0:11:46.960 eight years to grow between one and one point five inches. 0:11:47.800 --> 0:11:50.800 So you might see the seed fall leave, come back 0:11:51.000 --> 0:11:53.800 ten years later and it's still you know, it's a 0:11:53.800 --> 0:11:59.000 little little guy like that. Growth rates do accelerate after 0:11:59.240 --> 0:12:02.240 that that early earliest decade, so it's not eight years 0:12:02.280 --> 0:12:04.760 for every inch or inch and a half of the 0:12:04.760 --> 0:12:09.520 cactus's height, but it still grows very slowly across its lifespan. 0:12:10.160 --> 0:12:14.880 The Jetman at All book says that after twenty five years, 0:12:14.960 --> 0:12:17.920 they are usually still less than a meter in height, 0:12:18.800 --> 0:12:23.960 so incredibly slow growth. Depending on regional variations in climate, 0:12:24.080 --> 0:12:28.000 it usually takes somewhere between fifty and one hundred years 0:12:28.480 --> 0:12:32.240 for a swaro to get its first branch, the first 0:12:32.400 --> 0:12:35.839 arm coming out wave and saying hello. Between fifty and 0:12:35.840 --> 0:12:39.439 one hundred years for that, and a major factor in 0:12:39.480 --> 0:12:42.000 the rate of growth seems to be the level of 0:12:42.200 --> 0:12:48.120 moisture in the environment, so wetter conditions mean faster growth 0:12:48.240 --> 0:12:51.840 and earlier branching, or at least usually mean that. The 0:12:51.880 --> 0:12:55.360 authors of the book also note that variation in temperatures 0:12:55.440 --> 0:12:57.920 during the winter to spring period seem to have a 0:12:58.000 --> 0:13:02.320 pretty powerful effect on growth rates, with temperature volatility in 0:13:02.400 --> 0:13:06.320 the early warm season negatively affecting growth, and I think 0:13:06.360 --> 0:13:09.320 this is a fact they link to the idea of 0:13:09.400 --> 0:13:13.000 increased temperature volatility coming with climate change. Obviously that puts 0:13:13.160 --> 0:13:18.640 sorrows somewhat at risk, but even in the most favorable conditions, 0:13:19.000 --> 0:13:22.960 it's probably going to be fifty years before a cactus 0:13:22.960 --> 0:13:27.920 goes from seedling to getting an arm. The normal natural 0:13:28.320 --> 0:13:31.600 full lifespan of the swarow is somewhere between one hundred 0:13:31.600 --> 0:13:35.320 and fifty and two hundred years, so you know they live, 0:13:35.840 --> 0:13:40.439 They live across multiple human generations and take multiple human 0:13:40.480 --> 0:13:44.600 generations even to become the more recognizable mature shape. 0:13:44.840 --> 0:13:47.920 Yeah, and this is something like a number of these 0:13:47.920 --> 0:13:50.959 details important to keep in mind later when we discuss 0:13:51.040 --> 0:13:56.200 the indigenous indigenous mythic dimensions of the Sowara. 0:13:56.679 --> 0:13:59.720 So Another question is when those soarrows get to the 0:13:59.720 --> 0:14:02.360 mature stage, you know, they're reaching the end of their 0:14:02.360 --> 0:14:04.720 lifespan at one hundred and fifty or two hundred years 0:14:05.080 --> 0:14:09.280 of age. How do they die? It seems older, taller 0:14:09.320 --> 0:14:12.680 sonarrows are vulnerable to being blown over by wind and 0:14:13.040 --> 0:14:17.040 to being struck by lightning, which happens most often during 0:14:17.080 --> 0:14:22.120 summer monsoon conditions. In the colder, more northern regions of 0:14:22.120 --> 0:14:25.520 the Sonoran Desert, old soorrows are more likely to die 0:14:25.600 --> 0:14:30.880 from freezes during winter. And this is interesting because whereas 0:14:31.080 --> 0:14:34.640 something like lightning strikes or wind might have a more 0:14:35.200 --> 0:14:38.520 you know, varied you might pick out individuals in a population, 0:14:38.800 --> 0:14:42.880 especially big top heavy ones, or you know, the individual 0:14:42.920 --> 0:14:46.600 lightning strikes might take out individual soorrows in a In 0:14:46.640 --> 0:14:50.120 the more northern regions, a local freeze can kind of 0:14:50.160 --> 0:14:52.640 wipe out a whole crop, a whole local crop of 0:14:52.720 --> 0:14:57.480 cactus all at once. Another interesting fact they were talking 0:14:57.520 --> 0:15:01.520 about is that if you see a sar with a 0:15:01.560 --> 0:15:05.680 branch that droops downward instead of reaching up, you know 0:15:05.720 --> 0:15:08.600 it's got the arm turned down. This is often a 0:15:08.720 --> 0:15:12.720 result of injury from freezing conditions in the past. So 0:15:12.760 --> 0:15:15.800 maybe there was a freeze that didn't fully kill the cactus, 0:15:16.120 --> 0:15:18.320 but it injured the tissues, and so now it's got 0:15:18.320 --> 0:15:19.200 a drooping arm. 0:15:19.400 --> 0:15:20.200 Oh. Interesting. 0:15:20.440 --> 0:15:24.640 Yeah, But beyond the wind, the lightning, and the cold, 0:15:24.960 --> 0:15:29.880 the soorrow book points out some interesting types of vulnerability 0:15:29.920 --> 0:15:34.240 you might not expect, especially given how massive and hardy 0:15:34.440 --> 0:15:37.800 and well defended these plants seem to be. So you 0:15:37.800 --> 0:15:40.280 would think, you know, like nothing can hurt them. You know, 0:15:40.480 --> 0:15:43.560 they got all the spines, they're huge. But the author 0:15:43.640 --> 0:15:47.840 is right. Quote John Alcock, who monitored the same soarrows 0:15:47.920 --> 0:15:50.920 through the year over many years time, found that a 0:15:51.000 --> 0:15:54.960 mechanical injury as simple as constant rubbing by a palo 0:15:55.080 --> 0:15:59.520 verdi or ironwood branch could render a soarrow susceptible to 0:15:59.640 --> 0:16:04.080 disease and ultimate rot. So they are susceptible to especially 0:16:04.080 --> 0:16:07.680 if they get abrasions on their skin. You know, something 0:16:07.840 --> 0:16:10.600 kind of cuts into them, or hurts them, or just 0:16:10.680 --> 0:16:13.920 kind of rubs them enough, they can get these bacterial 0:16:14.160 --> 0:16:18.640 or fungal infections. They can get these infections that ultimately, 0:16:19.560 --> 0:16:22.760 you know, spread through the tissue of the plant and 0:16:22.920 --> 0:16:26.920 kill it. The authors also provide some interesting and I 0:16:27.000 --> 0:16:31.280 think vivid descriptions of the death of a sorrow. To 0:16:31.360 --> 0:16:35.960 paraphrase Hemingway, the soorrow often tends to die slowly and 0:16:36.000 --> 0:16:39.480 then all at once. So the slowly part is that 0:16:40.120 --> 0:16:43.240 you can get this kind of in between life and 0:16:43.400 --> 0:16:49.080 death zombie mode cactus stage where a doomed soorrow has 0:16:49.160 --> 0:16:53.200 been has been lethally injured, like it has been through 0:16:53.240 --> 0:16:58.000 a lethal freeze, but it may continue after that to 0:16:58.160 --> 0:17:02.680 stand upright and produce flowers, that produce flowers and fruit 0:17:02.800 --> 0:17:06.399 for years, but it's not going to survive. It is 0:17:06.480 --> 0:17:10.240 now doomed inevitably to die within a certain timeframe, usually 0:17:10.359 --> 0:17:13.800 less than a decade. But in the time between it 0:17:13.960 --> 0:17:18.960 keeps on living, keeps on doing reproductive activity. But in 0:17:19.040 --> 0:17:23.639 the final stage of death this comes on with shocking speed. Quote, 0:17:24.000 --> 0:17:26.960 what recently appeared to be a healthy plant may over 0:17:27.040 --> 0:17:30.440 a period of a few weeks, turn yellow, then brown, 0:17:30.800 --> 0:17:34.520 then brown, with black streaks, branches will collapse and fall, 0:17:34.800 --> 0:17:39.760 and finally these sickly outer layers will slough off. And 0:17:39.800 --> 0:17:42.520 I connected this with images of the cacti that we 0:17:42.560 --> 0:17:45.240 talked about last time, with that peeled away skin. Look. 0:17:45.840 --> 0:17:49.600 Yeah, yeah, and we see the ribs inside them that 0:17:50.280 --> 0:17:55.159 those hard woody rods that give them their structure and 0:17:55.200 --> 0:17:56.000 their integrity. 0:17:56.320 --> 0:18:00.240 Yeah. And so that structure, that internal structure can help 0:18:00.800 --> 0:18:04.600 continue to hold the cactus up even after its you know, 0:18:04.720 --> 0:18:08.000 softer tissues and the flesh are you know, have been 0:18:08.119 --> 0:18:12.080 critically damaged by freezes, or are infected with rod or 0:18:12.080 --> 0:18:15.600 something like that. But eventually it all, it all falls apart. 0:18:17.200 --> 0:18:19.320 Another thing that the author has mentioned. I didn't make 0:18:19.359 --> 0:18:21.040 a note of this, but I just remembered it is 0:18:21.359 --> 0:18:25.600 you can get a weird situation where sometimes a big 0:18:25.720 --> 0:18:28.920 mature cactus gets knocked over, maybe it gets blown over 0:18:28.960 --> 0:18:31.120 by wind or something, so it falls over, but it's 0:18:31.160 --> 0:18:34.040 still sort of alive for a bit, so it falls 0:18:34.119 --> 0:18:36.639 but continues to produce fruit and flowers. 0:18:36.920 --> 0:18:39.919 Oh wow, Well, I guess we see that with with 0:18:40.040 --> 0:18:43.320 trees as well. Sometimes the tree has been knocked over 0:18:43.400 --> 0:18:46.560 by one or fallen to one cause or another, but 0:18:46.600 --> 0:18:48.800 it's still going to continue doing the best. 0:18:48.600 --> 0:19:00.160 It can't at life. 0:19:00.680 --> 0:19:02.920 The thing I wanted to come back to is that 0:19:03.160 --> 0:19:06.440 before the sowaro gets to the mature reproductive stage of 0:19:06.440 --> 0:19:10.159 its life, it has to pass through a brutal gauntlet 0:19:10.240 --> 0:19:13.440 of survival. Rob You were talking about this in the 0:19:13.440 --> 0:19:17.280 The Unbelievable ratio of like how many seeds are produced 0:19:17.359 --> 0:19:22.840 versus how many actually survive to become a mature adult cactus. Again, 0:19:22.960 --> 0:19:25.159 most of the info here is coming from that the 0:19:25.240 --> 0:19:29.159 Yetna at All book. You mentioned earlier that the swaro 0:19:29.280 --> 0:19:32.840 tends to set fruit in the early summer, and this 0:19:33.000 --> 0:19:36.119 is usually going to be between June, mid June and 0:19:36.160 --> 0:19:39.640 early July, and that this is timed to come right 0:19:39.680 --> 0:19:44.800 before the summer monsoon rains. This is because the seed, 0:19:45.040 --> 0:19:47.639 you know, the goal is there's a seed inside the fruit, 0:19:48.000 --> 0:19:51.280 and the plant wants to disperse those seeds. And the 0:19:51.320 --> 0:19:54.720 seeds are going to be dispersed either by animal transport, 0:19:54.840 --> 0:19:57.280 so they'll be dispersed in the maybe the feces of 0:19:57.320 --> 0:19:59.439 an animal that ate the fruit. This could be a 0:19:59.480 --> 0:20:03.200 bat or one of many species of bird, or sometimes 0:20:03.240 --> 0:20:05.399 it'll disperse just by falling. You know, it's not going 0:20:05.480 --> 0:20:10.040 to get as far that way. But yeah, it's trying 0:20:10.040 --> 0:20:12.960 to disperse the seeds. But when the seed hits the ground, 0:20:13.200 --> 0:20:17.960 the seed needs warm, moist soil in order to germinate. 0:20:18.800 --> 0:20:23.639 And the authors we're talking here about how a huge 0:20:23.680 --> 0:20:26.359 amount of the seeds fall in places where they're just 0:20:26.520 --> 0:20:29.240 not going to have a chance to germinate and survive. 0:20:29.840 --> 0:20:33.000 Sometimes they get eaten by granivores like doves and bats, 0:20:33.040 --> 0:20:35.800 and then they'll get pooped out on a rock surface 0:20:36.080 --> 0:20:39.119 or inside a cave roost or some of their dark place, 0:20:39.680 --> 0:20:42.520 or they'll get dropped in an open area that's blasted 0:20:42.600 --> 0:20:45.359 dry by the sun, so they just don't have a chance. 0:20:45.840 --> 0:20:47.719 Now, I do want to add, for anyone who's not 0:20:47.720 --> 0:20:52.840 familiar with this landscape, you do following a heavy rain, 0:20:52.920 --> 0:20:56.359 you do have these wet areas. And I again, I 0:20:56.400 --> 0:21:01.160 am a visitor to the Sonoran Desert. I don't regularly 0:21:01.200 --> 0:21:03.800 spend my time there, but on my most recent trip, 0:21:03.840 --> 0:21:05.560 we did go for a nice hike, a couple of 0:21:05.640 --> 0:21:09.439 hikes in the Suarrows range, and it was for me 0:21:09.560 --> 0:21:11.680 kind of surreal to be out. You know, it's it's 0:21:11.800 --> 0:21:16.080 dry in so many respects. You're in the desert. You're 0:21:16.200 --> 0:21:18.480 very concerned about how much water you have on you 0:21:18.520 --> 0:21:20.280 And at the time I was running just a little 0:21:20.320 --> 0:21:22.399 bit low, not dangerously low, but it was a little low. 0:21:22.400 --> 0:21:23.720 It's like, okay, I need to get back and get 0:21:23.720 --> 0:21:28.040 some water. But then you're also passing puddles that are 0:21:28.080 --> 0:21:31.120 still standing. You know, you're you're you're stepping, you're walking 0:21:31.160 --> 0:21:37.120 through soft earth because of the recent rain, and so yeah, 0:21:36.520 --> 0:21:42.560 it can almost seem it can be very difficult to imagine, 0:21:42.560 --> 0:21:46.720 I think if you haven't encountered this in this environment. 0:21:47.119 --> 0:21:51.199 Yeah, yeah, so there will be seasonal rains and that 0:21:51.400 --> 0:21:53.000 we'll get more into this in a minute. But the 0:21:53.359 --> 0:21:59.080 swarrow is very biologically poised to take maximum advantage of 0:21:59.160 --> 0:22:02.560 when these frequent and seasonal rains do come, so that 0:22:02.640 --> 0:22:06.320 it has water stores to tide it over through the 0:22:06.359 --> 0:22:10.439 periods of drought. But the seedling has all these things 0:22:10.480 --> 0:22:13.720 to contend with, it might get dropped in a place 0:22:13.760 --> 0:22:19.040 that's not favorable for germination. Not to mention how rarely 0:22:19.400 --> 0:22:25.040 in time the overall climatic conditions align for the seedlings 0:22:25.119 --> 0:22:29.320 to germinate. The authors of the book note that quote 0:22:29.400 --> 0:22:33.080 the necessary conditions for germination of seeds and survival of 0:22:33.160 --> 0:22:39.000 seedlings seldom occur, perhaps ten times per century, often less 0:22:39.040 --> 0:22:42.360 frequently still, so that's sort of the good case scenario 0:22:42.680 --> 0:22:45.919 tend to. You know, it can go be a long 0:22:46.080 --> 0:22:50.439 time in between the years when things work out just 0:22:50.600 --> 0:22:54.879 right for the young souarros to you know, to germinate 0:22:55.000 --> 0:22:59.639 and then to survive through their youngest lives. And this 0:22:59.720 --> 0:23:06.199 leads to two very interesting consequences. One is areas with 0:23:06.560 --> 0:23:11.240 tons of Sorrows all roughly the same size, and that's 0:23:11.240 --> 0:23:15.399 because they're all pretty much the same age. It's like 0:23:15.480 --> 0:23:18.960 a cohort or a crop that came from one of 0:23:19.000 --> 0:23:22.919 these periods when they all grew up together, when the 0:23:22.960 --> 0:23:26.120 conditions were right, and so you're not getting a lot 0:23:26.119 --> 0:23:29.120 of in between because you know, there are long gaps 0:23:29.160 --> 0:23:33.320 in between these periods when conditions are right. And it 0:23:33.480 --> 0:23:39.080 also leads to areas that are Soorrow habitats, but at 0:23:39.160 --> 0:23:43.200 certain times in history seem to have no mature soarrows, 0:23:44.080 --> 0:23:49.360 and this latter condition can can cause and historically has 0:23:49.520 --> 0:23:54.680 caused periods of what we might call illusory extinction. So 0:23:54.800 --> 0:23:58.400 the authors mention this in the case of the eastern 0:23:58.520 --> 0:24:02.680 unit of Soorrow National Park, where between the time the 0:24:02.720 --> 0:24:06.000 park was established in nineteen thirty six, and some surveys 0:24:06.000 --> 0:24:10.480 that were done in the nineteen sixties, nearly all of 0:24:10.520 --> 0:24:14.879 the mature souarros disappeared. Quote, what was once a soorrow 0:24:14.960 --> 0:24:21.320 forest became a comparatively uninteresting and structurally nondescript desert landscape. 0:24:21.400 --> 0:24:22.359 Now that's alarming. 0:24:23.000 --> 0:24:24.720 Yeah, yeah, I believe this is the case where they 0:24:24.760 --> 0:24:26.920 have some photographs in the book of this Yeah. 0:24:27.040 --> 0:24:31.919 Yeah, And some casual observers were deeply disturbed. You know, 0:24:32.000 --> 0:24:34.480 they thought the suarros had gone extinct in the area, 0:24:34.520 --> 0:24:38.160 but they had not. The reality was that people were 0:24:38.280 --> 0:24:42.680