1 00:00:01,920 --> 00:00:04,320 Speaker 1: Welcome to brain Stuff, a production of I Heart Radio, 2 00:00:06,240 --> 00:00:11,280 Speaker 1: Hey brain Stuff, Lauren Bogabam. Here, something perhaps even weirder 3 00:00:11,280 --> 00:00:14,760 Speaker 1: than usual is happening in Florida. I grew up there, 4 00:00:14,800 --> 00:00:18,240 Speaker 1: so I can make that joke. In case you hadn't heard. 5 00:00:18,400 --> 00:00:22,440 Speaker 1: Iguanas are all but overrunning the Sunshine State, and we're 6 00:00:22,480 --> 00:00:25,759 Speaker 1: talking about big lizards. They're thriving there because of South 7 00:00:25,760 --> 00:00:30,520 Speaker 1: Florida's subtropical climate and the lack of natural predators, while 8 00:00:30,560 --> 00:00:33,280 Speaker 1: there are lots of non native saurians trudging through the 9 00:00:33,320 --> 00:00:36,720 Speaker 1: area more like the forked tongued denial monitor. The creature 10 00:00:36,760 --> 00:00:40,920 Speaker 1: we're specifically alluding to here is the green iguana, taxonomical 11 00:00:41,000 --> 00:00:44,920 Speaker 1: name Iguana iguana. It ranks among the largest lizards in 12 00:00:44,960 --> 00:00:48,760 Speaker 1: the Western Hemisphere. Adult females can be five feet that's 13 00:00:48,800 --> 00:00:51,080 Speaker 1: one and a half meters in length, while the biggest 14 00:00:51,080 --> 00:00:53,880 Speaker 1: males may reach an impressive seven feet or two meters 15 00:00:54,000 --> 00:00:57,160 Speaker 1: long from nose to tail tip. An average weight is 16 00:00:57,200 --> 00:01:00,280 Speaker 1: around fifteen pounds or four and a half kilos, though 17 00:01:00,360 --> 00:01:03,440 Speaker 1: heavier specimens weighing seventeen pounds or seven and a half 18 00:01:03,480 --> 00:01:07,959 Speaker 1: kilos or more have been documented, and despite its proportions, 19 00:01:07,959 --> 00:01:10,600 Speaker 1: The species has long been a staple in the exotic 20 00:01:10,640 --> 00:01:14,600 Speaker 1: pet trade and unfortunately a victim of abandonment when they 21 00:01:14,640 --> 00:01:18,360 Speaker 1: get too big. That's helped these critters spread far beyond 22 00:01:18,480 --> 00:01:22,920 Speaker 1: their natural range, causing property damage and competition with native wildlife. 23 00:01:24,200 --> 00:01:27,800 Speaker 1: By and large, green iguanas are herbivores. They may eat 24 00:01:27,840 --> 00:01:30,800 Speaker 1: insects or dead meat on occasion, but it's fruits and 25 00:01:30,880 --> 00:01:34,800 Speaker 1: leaves that make up the bulk of their diet. Though too, 26 00:01:34,880 --> 00:01:38,680 Speaker 1: green iguanas vegetation isn't just a food source. This is 27 00:01:38,720 --> 00:01:42,200 Speaker 1: a tree loving animal that, given its druthers, spends most 28 00:01:42,240 --> 00:01:46,880 Speaker 1: of its time basking in forest canopies. Scaling branches comes 29 00:01:46,880 --> 00:01:50,640 Speaker 1: easily to the lizards. With their long fingers and hooked claws. 30 00:01:50,680 --> 00:01:54,000 Speaker 1: These guys are first rate climbers. Of course, you don't 31 00:01:54,000 --> 00:01:57,320 Speaker 1: spend a lifetime in the treetops without taking the occasional spill. 32 00:01:58,000 --> 00:02:00,680 Speaker 1: Green iguanas have been known to withstand fift foot that's 33 00:02:00,720 --> 00:02:06,080 Speaker 1: fifteen meter falls and walk away uninjured. This species is 34 00:02:06,120 --> 00:02:09,720 Speaker 1: also perfectly at home in the water. I'm much like alligators. 35 00:02:09,760 --> 00:02:13,040 Speaker 1: The animals swim by undulating their tails from side to side. 36 00:02:13,680 --> 00:02:16,480 Speaker 1: Frightened iguana might also choose to seek refuge below the 37 00:02:16,520 --> 00:02:20,400 Speaker 1: surface if a predator is lurking about. We are not 38 00:02:20,520 --> 00:02:23,840 Speaker 1: used to thinking of non avian reptiles as sociable, but 39 00:02:23,919 --> 00:02:27,840 Speaker 1: yet the green iguana is somewhat gregarious. Hatchlings are born 40 00:02:27,919 --> 00:02:32,360 Speaker 1: in underground nests, sometimes in the vicinity of crocodilians. Baby 41 00:02:32,400 --> 00:02:35,960 Speaker 1: iguanas stick together, forming social groups with their siblings for 42 00:02:36,120 --> 00:02:40,520 Speaker 1: mutual protection. Such units can last for months, during which 43 00:02:40,560 --> 00:02:43,360 Speaker 1: time the young lizards groom one another and sleep side 44 00:02:43,360 --> 00:02:48,760 Speaker 1: by side or in piles iguana. Iguana is sexually dimorphic, 45 00:02:49,000 --> 00:02:53,400 Speaker 1: with females looking visibly different from their masculine counterparts. Both 46 00:02:53,440 --> 00:02:57,080 Speaker 1: sexes have dew laps, that's folds of loose skin that 47 00:02:57,200 --> 00:03:01,200 Speaker 1: dangle below the neck. These are proportionately larger in males 48 00:03:01,240 --> 00:03:05,359 Speaker 1: and an important communication tool. Come breeding season, a male 49 00:03:05,400 --> 00:03:09,320 Speaker 1: iguana will defend a huge territory and ideally mate with 50 00:03:09,360 --> 00:03:12,560 Speaker 1: a number of females, whom he'll guard for an extended period. 51 00:03:13,240 --> 00:03:16,440 Speaker 1: To scare off rivals, males aggressively bob their heads up 52 00:03:16,480 --> 00:03:21,399 Speaker 1: and down, dew laps flapping all the while. While we're here, 53 00:03:21,520 --> 00:03:25,480 Speaker 1: let's discuss coloration and not all green iguanas are literally 54 00:03:25,520 --> 00:03:28,640 Speaker 1: green They also come in shades of brown, blue, red, 55 00:03:28,720 --> 00:03:32,160 Speaker 1: and gray, and males often turn orange or bronze ish 56 00:03:32,160 --> 00:03:36,000 Speaker 1: when it's time to court potential mates. Today, the green 57 00:03:36,040 --> 00:03:39,720 Speaker 1: iguana remains one of the United states most popular reptilian pets, 58 00:03:40,160 --> 00:03:42,960 Speaker 1: but that doesn't mean they're easy to care for. Sharing 59 00:03:43,040 --> 00:03:45,880 Speaker 1: your life with an iguana can be deeply rewarding, but 60 00:03:45,960 --> 00:03:49,480 Speaker 1: you should know what you're getting into beforehand. Hatchlings will 61 00:03:49,520 --> 00:03:52,280 Speaker 1: be about eight inches that's twenty centimes long, and might 62 00:03:52,400 --> 00:03:56,880 Speaker 1: fare nicely in a tabletop terrarium, but experienced hobbyists recommend 63 00:03:56,920 --> 00:03:59,840 Speaker 1: that adult enclosures measure at least six ft high by 64 00:04:00,080 --> 00:04:03,200 Speaker 1: x feet wide and twelve feet long in meters that's 65 00:04:03,200 --> 00:04:07,400 Speaker 1: about two by two by three and a half. Before 66 00:04:07,480 --> 00:04:11,000 Speaker 1: it was artificially introduced to new environments, the green iguana 67 00:04:11,120 --> 00:04:14,000 Speaker 1: was restricted to Central and South America, along with a 68 00:04:14,040 --> 00:04:17,920 Speaker 1: smattering of islands in the Eastern Pacific and Caribbean. Back 69 00:04:17,960 --> 00:04:21,680 Speaker 1: in at least fifteen of the lizards suddenly appeared on 70 00:04:21,720 --> 00:04:25,120 Speaker 1: a Caribbean island with no pre existing green iguana population. 71 00:04:25,720 --> 00:04:29,320 Speaker 1: The scientists think the reptiles road floating mats of uprooted 72 00:04:29,400 --> 00:04:32,039 Speaker 1: vegetation that drifted out to sea in the wake of 73 00:04:32,120 --> 00:04:36,719 Speaker 1: Hurricanes Luis and Maryland. Presumably the raft bound castaways traveled 74 00:04:36,760 --> 00:04:39,480 Speaker 1: all the way from Guadaloupe, some two hundred miles or 75 00:04:39,560 --> 00:04:45,240 Speaker 1: three kilometers to the south. Unfortunately, when the local climate 76 00:04:45,320 --> 00:04:48,520 Speaker 1: is favorable, iguana iguana can thrive in places where it 77 00:04:48,560 --> 00:04:53,200 Speaker 1: doesn't belong. In nineteen sixty six, the first scientific report 78 00:04:53,240 --> 00:04:56,719 Speaker 1: on invasive iguanas in South Florida was published. It seems 79 00:04:56,760 --> 00:04:59,880 Speaker 1: likely that many individuals reached the Florida and Peninsula by 80 00:05:00,040 --> 00:05:03,960 Speaker 1: going away on boats and in shipping crates. America's booming 81 00:05:03,960 --> 00:05:08,640 Speaker 1: pet industry sure didn't help alone. More than one point 82 00:05:08,680 --> 00:05:11,880 Speaker 1: one four million iguanas were imported into the United States. 83 00:05:12,480 --> 00:05:15,919 Speaker 1: Although it's possible to buy captive bread specimens nowadays, a 84 00:05:16,000 --> 00:05:18,559 Speaker 1: wild cop babies are still being shipped to the US 85 00:05:18,640 --> 00:05:24,039 Speaker 1: and mass It's unclear how many free ranging green iguanas 86 00:05:24,080 --> 00:05:27,400 Speaker 1: are loose in South Florida. More than seven thousand iguana 87 00:05:27,440 --> 00:05:29,919 Speaker 1: sidings have been recorded by the University of Georgia's Early 88 00:05:29,960 --> 00:05:34,440 Speaker 1: Detection and Distribution Mapping system. Since most of those after, 89 00:05:36,160 --> 00:05:38,440 Speaker 1: a large percentage of the lizards now running about the 90 00:05:38,440 --> 00:05:43,840 Speaker 1: state probably descend from escaped or unwanted pets. Ecologists warned 91 00:05:43,880 --> 00:05:47,440 Speaker 1: that the herbivores are devouring important native plants, including a 92 00:05:47,480 --> 00:05:51,360 Speaker 1: coastal vine that the endangered Miami blue butterfly lava feed on. 93 00:05:52,279 --> 00:05:55,560 Speaker 1: Various flowers may also be at risk. A green iguanas 94 00:05:55,600 --> 00:05:58,719 Speaker 1: have been turning private gardens into buffets, and to add 95 00:05:58,720 --> 00:06:02,599 Speaker 1: insult to injury, the Szard's leave feces on patios, boat decks, 96 00:06:02,640 --> 00:06:06,800 Speaker 1: and other surfaces, and metaling iguanas are doing a number 97 00:06:06,880 --> 00:06:10,960 Speaker 1: on Florida's infrastructure too, and just one iguana caused a 98 00:06:11,040 --> 00:06:13,800 Speaker 1: ten minute power outage when it trespassed on a key 99 00:06:13,800 --> 00:06:17,880 Speaker 1: West Electrical facility in two thousand eighteen, and West Palm 100 00:06:17,920 --> 00:06:21,000 Speaker 1: Beach is facing one point eight million dollars in damages 101 00:06:21,040 --> 00:06:25,800 Speaker 1: incurred after tunneling iguanas messed up a local dam. In 102 00:06:25,839 --> 00:06:29,400 Speaker 1: twenty nineteen, the Florida Fish and Wildlife Conservation Commission made 103 00:06:29,400 --> 00:06:33,600 Speaker 1: headlines by encouraging homeowners to humanely kill green iguanas on 104 00:06:33,640 --> 00:06:37,400 Speaker 1: their property whenever possible. One doesn't need a license or 105 00:06:37,440 --> 00:06:41,200 Speaker 1: permit to hunt them on public lands. The several worried 106 00:06:41,240 --> 00:06:44,560 Speaker 1: citizens have also called for Floridians to eat more iguana meat, 107 00:06:44,760 --> 00:06:47,359 Speaker 1: which is a traditional protein in parts of the Caribbean. 108 00:06:49,000 --> 00:06:52,200 Speaker 1: Being cold blooded, iguanas have been unable to establish viable 109 00:06:52,200 --> 00:06:56,040 Speaker 1: populations in northern recesses of the state. Even down south, 110 00:06:56,279 --> 00:07:00,440 Speaker 1: the lizards occasionally fall victim to chili conditions. The animals 111 00:07:00,480 --> 00:07:03,440 Speaker 1: go into paralysis when the thermometer hits forty four degrees 112 00:07:03,520 --> 00:07:07,320 Speaker 1: fahrenheit or six point six celsius, which doesn't happen often 113 00:07:07,360 --> 00:07:12,040 Speaker 1: in South Florida but did in January another cold snap 114 00:07:12,040 --> 00:07:16,280 Speaker 1: in killed off a large part of the iguana population. However, 115 00:07:16,400 --> 00:07:19,480 Speaker 1: once the weather warms again, most adult iguanas can recover 116 00:07:19,600 --> 00:07:23,520 Speaker 1: from this kind of temporary incapacitation. You do will to 117 00:07:23,600 --> 00:07:26,560 Speaker 1: keep your distance. In the meantime, a stirring iguana can 118 00:07:26,640 --> 00:07:34,680 Speaker 1: really bite. Today's episode is based on the article South 119 00:07:34,720 --> 00:07:38,200 Speaker 1: Florida is overrun with green Iguanas on housetuffworks dot com, 120 00:07:38,240 --> 00:07:41,239 Speaker 1: written by Mark Mancini. Brain Stuff is production of iHeart 121 00:07:41,320 --> 00:07:43,480 Speaker 1: Radio in partnership with how stuff works dot Com and 122 00:07:43,600 --> 00:07:46,520 Speaker 1: is produced by Tyler Clang. Four more podcasts from my 123 00:07:46,560 --> 00:07:49,640 Speaker 1: heart Radio visit the iHeart Radio app, Apple Podcasts, or 124 00:07:49,640 --> 00:07:51,400 Speaker 1: wherever you listen to your favorite shows.