WEBVTT - How Do Coconut Crabs Work?

0:00:01.800 --> 0:00:04.320
<v Speaker 1>Welcome to brain Stuff, a production of I Heart Radio.

0:00:06.720 --> 0:00:10.760
<v Speaker 1>Hey brain Stuff, Lauren Boga bom Here. If you or

0:00:10.840 --> 0:00:13.200
<v Speaker 1>a friend had a hermit crab when you were a kid,

0:00:13.480 --> 0:00:16.360
<v Speaker 1>or if you have one now, you're familiar with how

0:00:16.400 --> 0:00:19.279
<v Speaker 1>they'll make a home in a snail shell in the

0:00:19.320 --> 0:00:23.079
<v Speaker 1>wild or a terrarium. They'll squeeze into an empty shell

0:00:23.200 --> 0:00:25.640
<v Speaker 1>that's just the right size for them to carry around

0:00:25.680 --> 0:00:29.520
<v Speaker 1>as mobile protection. They're soft bellies, sheltered and their legs

0:00:29.600 --> 0:00:32.680
<v Speaker 1>free for crawling. Most of the ones we keep as

0:00:32.720 --> 0:00:35.120
<v Speaker 1>pets in the US are just an inch or too long,

0:00:35.360 --> 0:00:39.960
<v Speaker 1>up to about five centimeters. Okay, now picture that little buddy,

0:00:40.120 --> 0:00:43.559
<v Speaker 1>but twenty to thirty times larger and having grown just

0:00:43.840 --> 0:00:46.680
<v Speaker 1>enough offenses that they no longer need to carry a

0:00:46.800 --> 0:00:50.320
<v Speaker 1>defensive shell. And that's what you're looking at when you

0:00:50.360 --> 0:00:54.160
<v Speaker 1>consider the coconut crab, a close cousin to the pet

0:00:54.160 --> 0:00:56.960
<v Speaker 1>hermit crabs that we keep. The coconut crab is native

0:00:56.960 --> 0:00:59.760
<v Speaker 1>to the islands in the Pacific and Indian Oceans, and

0:00:59.760 --> 0:01:03.800
<v Speaker 1>they're the world's biggest land dwelling arthropods. They can weigh

0:01:03.880 --> 0:01:06.360
<v Speaker 1>up to nine pounds that's about four kilos with a

0:01:06.440 --> 0:01:10.680
<v Speaker 1>leg span of around three ft or one meter. This

0:01:10.800 --> 0:01:12.840
<v Speaker 1>is only about the third of the leg span of

0:01:12.840 --> 0:01:16.440
<v Speaker 1>the Japanese spider crab, which is the biggest arthur pod period,

0:01:16.880 --> 0:01:19.160
<v Speaker 1>but as it's an ocean dweller, it has less of

0:01:19.160 --> 0:01:22.280
<v Speaker 1>a chance to startle us with its sheer size. Most

0:01:22.319 --> 0:01:26.679
<v Speaker 1>coconut crabs are longer than most dogs, and coconut crabs

0:01:26.680 --> 0:01:30.319
<v Speaker 1>have been known to eat kittens, rats, chickens, and each other.

0:01:31.080 --> 0:01:33.560
<v Speaker 1>They've even been proposed as a possible culprit in the

0:01:33.600 --> 0:01:36.960
<v Speaker 1>disappearance of the body of Amelia Earhart, as we've discussed

0:01:36.959 --> 0:01:40.960
<v Speaker 1>before on the show. For the article this episode is

0:01:40.959 --> 0:01:44.240
<v Speaker 1>based on How Stuff Works, spoke with Shinichio Oka, chief

0:01:44.280 --> 0:01:47.680
<v Speaker 1>research scientist at the Okinawa Choshima Research Center in Japan.

0:01:48.560 --> 0:01:52.240
<v Speaker 1>He said, the coconut crabs have no seashell as protection

0:01:52.320 --> 0:01:55.520
<v Speaker 1>from enemies, so they have powerful claws and a large

0:01:55.520 --> 0:01:59.360
<v Speaker 1>body to protect themselves. In addition, they're mighty claws. Let

0:01:59.360 --> 0:02:03.520
<v Speaker 1>the monopoly is the terrestrial hard foods, including coconuts, which

0:02:03.560 --> 0:02:08.799
<v Speaker 1>other animals are unable to get into. So exactly how

0:02:08.880 --> 0:02:12.880
<v Speaker 1>strong are the claws of a coconut crab? OCAs said,

0:02:13.360 --> 0:02:16.080
<v Speaker 1>we could find that coconut crabs can generate the pinching

0:02:16.120 --> 0:02:19.720
<v Speaker 1>force of ninety times of their body weight. The calculated

0:02:19.720 --> 0:02:22.600
<v Speaker 1>pinching force of the largest coconut crab is almost equal

0:02:22.639 --> 0:02:27.520
<v Speaker 1>to the bite force of the adult lions. So these

0:02:27.560 --> 0:02:32.400
<v Speaker 1>overgrown coconuts smashing kitten eating crustaceans are nightmare versions of

0:02:32.440 --> 0:02:35.400
<v Speaker 1>the petite and mildly pinchet hermit crabs that we know.

0:02:36.160 --> 0:02:38.840
<v Speaker 1>But they actually do spend some of their life cycle

0:02:38.919 --> 0:02:43.480
<v Speaker 1>in the same manner as their dainty your cousins. Coconut

0:02:43.520 --> 0:02:45.960
<v Speaker 1>crabs spend most of their lives on land, but they

0:02:45.960 --> 0:02:49.880
<v Speaker 1>start out in the sea. A female coconut crab deposits larva,

0:02:50.000 --> 0:02:52.400
<v Speaker 1>which she's been carrying around in her abdomen since they

0:02:52.400 --> 0:02:55.680
<v Speaker 1>were just fertilized eggs, into the ocean, and the babies

0:02:55.760 --> 0:02:57.800
<v Speaker 1>float around in the currents for a month or so

0:02:58.240 --> 0:03:01.040
<v Speaker 1>eating other plankton, before gay enough body weight that they

0:03:01.120 --> 0:03:04.320
<v Speaker 1>dropped the sea floor and find nice cozy snail shells

0:03:04.320 --> 0:03:08.400
<v Speaker 1>to move into. Just like your childhood hermit crab friend,

0:03:08.680 --> 0:03:11.240
<v Speaker 1>the young coconut crabs move in and out of shells

0:03:11.280 --> 0:03:14.120
<v Speaker 1>as they bulk up and get used to living on land,

0:03:14.840 --> 0:03:17.680
<v Speaker 1>and sometimes a juvenile coconut crab will use a coconut

0:03:17.760 --> 0:03:20.840
<v Speaker 1>husk or empty seashell is armor until its own shell

0:03:20.960 --> 0:03:25.480
<v Speaker 1>gets harder. After about a year, the teens of the

0:03:25.480 --> 0:03:28.520
<v Speaker 1>species eventually find that there are no shells left on

0:03:28.520 --> 0:03:31.440
<v Speaker 1>the beach large enough to accommodate their bulk, and so

0:03:31.520 --> 0:03:34.800
<v Speaker 1>they move out altogether. From here on out, they live

0:03:34.840 --> 0:03:37.280
<v Speaker 1>the rest of their lives out of the water. Adult

0:03:37.280 --> 0:03:40.920
<v Speaker 1>coconut crabs can't swim and will drown if totally submerged.

0:03:42.720 --> 0:03:46.720
<v Speaker 1>Adult coconut crabs bodies have kelcium based exo skeletons, which

0:03:46.840 --> 0:03:49.560
<v Speaker 1>hard enough more than hermit crabs do once they mature,

0:03:50.080 --> 0:03:52.800
<v Speaker 1>so they're free to grow as monstrous size as they

0:03:52.800 --> 0:03:56.680
<v Speaker 1>can manage. Every few months, coconut crabs molt their too

0:03:56.720 --> 0:03:59.720
<v Speaker 1>tight exo skeletons and then grow a larger one they

0:04:00.120 --> 0:04:03.080
<v Speaker 1>the old one after they've shed it. Coconut crabs will

0:04:03.080 --> 0:04:06.360
<v Speaker 1>eat almost anything, all kinds of fruit, plant matter, dead

0:04:06.400 --> 0:04:09.400
<v Speaker 1>animals they find lying around, food you've left lying around

0:04:09.520 --> 0:04:13.320
<v Speaker 1>other crab species, or even their own friends. Actually, coconut

0:04:13.320 --> 0:04:17.320
<v Speaker 1>crabs don't really have friends. They're pretty solitary. They have

0:04:17.480 --> 0:04:20.160
<v Speaker 1>an excellent sense of smell, which makes them great at

0:04:20.200 --> 0:04:25.200
<v Speaker 1>finding rotting carcasses and anything else potentially edible. Coconut crabs

0:04:25.200 --> 0:04:28.240
<v Speaker 1>are also sometimes called robber crabs because they've been known

0:04:28.279 --> 0:04:31.440
<v Speaker 1>to steal items like silverware that has even the faint

0:04:31.480 --> 0:04:36.560
<v Speaker 1>odor of food about it. But their most important source

0:04:36.600 --> 0:04:40.400
<v Speaker 1>of nutrients is coconuts. Because coconuts seem to be what

0:04:40.440 --> 0:04:44.480
<v Speaker 1>allows them to achieve the gigantism they're known for. Coconut

0:04:44.520 --> 0:04:47.240
<v Speaker 1>crabs will climb trees to get at coconuts and use

0:04:47.279 --> 0:04:51.640
<v Speaker 1>their pinchers to open them. Study found that the coconut

0:04:51.720 --> 0:04:54.599
<v Speaker 1>crabs that have access to coconuts are likely to have

0:04:54.720 --> 0:04:59.400
<v Speaker 1>around double the mass of those living in coconut free environments.

0:04:59.440 --> 0:05:02.720
<v Speaker 1>So a coconut crab is lucky enough to have coconuts around,

0:05:02.960 --> 0:05:05.640
<v Speaker 1>and if it's strong enough to pan opener its way

0:05:05.640 --> 0:05:08.560
<v Speaker 1>into a coconut, it's able to grow a lot bigger

0:05:08.839 --> 0:05:12.719
<v Speaker 1>and then access even more coconuts the size ceiling gets

0:05:12.760 --> 0:05:17.960
<v Speaker 1>a whole lot higher. But coconut crabs are not invulnerable,

0:05:18.680 --> 0:05:21.880
<v Speaker 1>their numbers seem to be declining, probably because the islands

0:05:21.920 --> 0:05:23.720
<v Speaker 1>that they live on aren't what they used to be.

0:05:24.320 --> 0:05:28.240
<v Speaker 1>Introduced species like dogs, pigs, and humans eat the adults,

0:05:28.480 --> 0:05:32.279
<v Speaker 1>and invasive rats gobble up the smaller, more vulnerable babies.

0:05:33.080 --> 0:05:35.960
<v Speaker 1>They're extremely slow growing and can live to be about

0:05:36.000 --> 0:05:39.719
<v Speaker 1>fifty years old. Coconut crabs have been listed as data

0:05:39.760 --> 0:05:43.719
<v Speaker 1>deficient by the International Union for Conservation of Nature, meaning

0:05:43.920 --> 0:05:46.960
<v Speaker 1>nobody really knows enough about these animals to understand their

0:05:47.000 --> 0:05:50.760
<v Speaker 1>conservation needs. Although it's likely that they're not doing well,

0:05:50.880 --> 0:05:54.839
<v Speaker 1>their status was last assessed in so more research is

0:05:54.880 --> 0:06:03.600
<v Speaker 1>needed to understand where coconut crabs stand m Today's episode

0:06:03.680 --> 0:06:05.800
<v Speaker 1>is based on the article called the coconut Crab, a

0:06:05.839 --> 0:06:08.679
<v Speaker 1>crustacean on steroids on house toff works dot com, written

0:06:08.680 --> 0:06:11.440
<v Speaker 1>by Jesselyn Shields. Brain Stuff is production of I Heart

0:06:11.480 --> 0:06:13.800
<v Speaker 1>Radio in partnership with how Stuffwork dot Com, and it's

0:06:13.839 --> 0:06:17.119
<v Speaker 1>produced by Tyler Clang. Four more podcasts my heart Radio

0:06:17.320 --> 0:06:20.000
<v Speaker 1>visit the i heart Radio app, Apple Podcasts, or wherever

0:06:20.040 --> 0:06:21.440
<v Speaker 1>you listen to your favorite shows.