The Lord of the Fellowship of the Island Dwarves of the Lesser Sunda Islands

We've already talked about island dwarfism several times on the blog, with examples as varied as the Zanzibar leopard, the dwarf dinosaurs of Hațeg Island, and the Channel Island fox from Catalina Island.  But now is the time for something that is several times more epic.  Today, we are going to look at the wacky, crazy, and very odd sized animals that were native to the island of Flores in Indonesia as recently as 20,000 years ago!  And oddly enough, this paleoenvironment had many similarities with the fantasy world of Middle Earth in Lord of the Rings.  Don't believe me and want to learn more?  Well that, my friends, is known as a hook, a literary device used in the opening paragraph of a work of literature to grab the readers attention.  So if you're not hooked right now, then that's because you don't like fun.  The day may come when your courage to read my blog fails....but it is not this day.  At least I hope not.

A size comparison of the brave little Hobbit, the dwarf elephant Stegodon, the Komodo dragon, and the giant stork Leptoptilos robustus, drawn by the illustrious illustrator Zach Evens!

If you aren't already familiar with island dwarfism, here's a brief summary.  Oftentimes, populations of animals will become trapped on islands.  Over deep time, they can either evolve and adapt....or die.  On islands, what was beneficial on the mainland might not be quite as useful on a smaller, isolated chunk of land.  For example, if you are a larger animal, you are going to need more food than a smaller animal.  On the mainland, where food can be found in relative abundance, this usually isn't as much of an issue.  Furthermore, being large helps ward off predators, and can increase the likelihood of passing off your genes to subsequent generations.  So for some mainland animals, it pays to be bigger.

Now slow down and grab on to something solid.  Imagine a group of elephants becomes isolated from the mainland, and trapped on an island with limited food supply and other resources.  Now all of a sudden, its the larger elephants that are dying off, starving to death.  The biggest of the bunch are unable to find enough food for their regular breakfast (not to mention second breakfast or elevenses), and unable to pass on their genes.  Suddenly, being small is looking pretty good!  Furthermore, if the island that these elephants are trapped on has geographical features that ensure mainland predators shall not pass onto the island, then the smaller elephants aren't being removed from the gene pool by predators.  If you hit the gas pedal and speed up a few thousand years or so, you might get a population of cute little pint-sized elephants.  Which, as we have talked about before, does indeed happen, and has happened numerous times throughout history.

So there's island dwarfism in a cute little nutshell.  This tiny little idea pertains to the island of Flores in a big way, as it potentially miniaturized a member of the human family tree!  Meet Homo floresiensis, nicknamed "the Hobbit" by its discoverers!  At only three and a half feet tall, this little guy would almost certainly be wasted at cross-country!  Initially announced in 2004, the discovery of at least six individuals of this cute little member of the human family tree have shown that this proto-human was not simply a genetic anomaly of this properly proportioned Pleistocene populace, but instead a participant in this posse of pint-sized people.

One small brained individual contemplates another.  The smaller skull is a cast of the skull of Homo floresiensis.  Photo Credit: Zach Evens

The evolutionary relationships of Homo floresiensis are still poorly understood, as different bits of the skeletal anatomy indicate different possible ancestors.  For example, brain shape, thick cranial bones, a short flat face, and a sloping forehead are features echoed in another early human, Homo erectus.  H. erectus does seem like a logical candidate for the ancestor of H. floresiensis, as H. erectus is thought to have inhabited southeast Asia as recently as half a million years ago.

Other scientists believe that there is more to this hobbit than meets the eye.  Not everything matches terribly well with the "Insular Dwarfing of Homo erectus as an Explanation Regarding the Small Stature of Homo Floresiensis" hypothesis.  In proportion to the rest of the body, the brain does not typically dwarf nearly as much when it comes to island dwarfism.  However, the Hobbit's brain size did seem to decrease dramatically, a phenomenon not typically seen in island dwarfs, with the possible exceptions of the Myotragus cave goat and the Malagasy hippo Hippopotamus lemerlei.  Therefore, some scientists hypothesize that H. floresiensis is not actually a dwarf at all, but was instead a "living fossil," an informal term used to describe animals whose closest relatives are all extinct.*  In this other scenario, scientists suspect that H. floresiensis shouldn't even belong to the genus Homo, and instead is a descendant of Australopithecus, another genus of ancestral human, members of which are thought to have survived as recently as two million years ago.  If H. floresiensis was instead a living fossil, then an island might be the perfect place for this brave little halfling to find refuge.

Besides dwarfism, islands can also serve as evolutionary holdout areas for animals that might not have been able to compete with other species on the mainland.  An excellent example of this is a member of the reptilian sphenodonts, lizard-like animals who can trace their evolutionary origins past that of lizards and snakes, all the way back to the Late Triassic Period, when dinosaurs were first evolving.  Today, the only place where you can find a living sphenodont, known colloquially as the tuatara, is on a number of small islands off the coast of New Zealand.  For whatever reason, this fascinating primitive reptile was unable to keep up with the rapid pace of evolution on the mainland, and found island life to be more its speed.  Unfortunately, introduced animals such as rats carry the potential to exterminate the tuatara within our lifetime.  With nowhere to go when the going gets tough, islands can be very dangerous places indeed.

Several lines of evidence support the idea of H. floresiensis actually being a descendant of Australopithecus, including morphological characteristics of the teeth and mandible, as well as the small brain size mentioned before.  A third hypothesis has been created to explain away the small size of this early human, which pertains to pathological conditions such as microcephaly, Laron Syndrome, and myxoedematous endemic hypothyroidism.  To read more about the support for and against these pathological conditions in regards to H. floresiensis, you can click HERE: this post goes ever on and on, and we still have a lot more ground to cover.  Besides, is it not strange that we should suffer so much fear and doubt over so small a being?  Such a little being.

A quality pic that shows a modern human skull on the left, and the skull of the Hobbit on the right.

"Boy, it sure would be easier to cover all of this ground if we could ride on the back of some giant elephant thing," thought an innovative member of the Haradrim people one day in Middle Earth.  Fortunately for this dreamer, he wasn't the only one who shared this vision.  The oliphaunts, giant relatives of elephants, were in no short supply, and were eventually made to carry large platforms on their backs.  Boy, that sure would be convenient if one of those dwarf elephants found their way onto Flores and got themselves shrunk, wouldn't it?  Well, lo and behold, meet Stegodon!  Although its mainland relatives were some of the largest proboscideans to ever evolve, a petite little version of Stegodon was endemic to the island of Flores at the same time the Hobbit was!

You know what else would have been easier?  If Frodo had taken an eagle and flown over Mt. Doom, and dropped the Ring into the volcano.**  It would be a little TOO convenient for there to be a giant eagle that lived on the island of Flores and, unfortunately, this time you are correct.  There was, however, a gigantic relative of the modern day Marabou stork, Leptoptilos robustus, which measured in at an enormous 6 feet tall!  Since it was so large, some scientists suspect that this fool would not have been doing much flying.  Instead, this gigantic stork is thought to have stalked the Pleistocene landscape of Flores, living a primarily terrestrial lifestyle, most likely due to a lack of mammalian predators.  Kind of the opposite of island dwarfism: instead of big animals getting smaller, its small animals getting bigger!  Boy, that sure would suck if that gigantism happened to something gross like rats, wouldn't it?

So we've got hobbits.  We've got elephants.  We've even got giant birds.  Is there anything we're missing?  Sure there is: dragons.  Although there weren't any fire breathing dragons on Flores during the Pleistocene, there was a gigantic lizard that prowled the landscape!  Meet the Komodo dragon which, as luck would have it, is actually still alive today!  At ten feet long and weighing several hundred pounds, the Komodo dragon is the heaviest lizard alive today, and will take humans as prey if given the opportunity.  As a matter of fact, there has even been some speculation that the Komodo dragon evolved so large in order to hunt the dwarf Stegodon that also made their home on the island, but as far as I know this is simply speculation.

Obviously, there is still a great deal that we need to learn about this ancient ecosystem, as well as about the individual species that were a part of said ecosystem.  Preciouusssssss fossils can be very difficult to find: unlike other inanimate objects, fossils don't really care one way or another if they are found by anyone, and just kind of sit there.  With any luck, in the coming years, paleontologists might discover evidence of humongous Floresian spiders, giant wolves, or intelligent trees.  Or maybe even elves.  Whatever the future holds, you can rest assured that I will be there to report on the new findings.  You have my word.

And my bow.

And my axe.



*Here on the blog, we've talked about animals such as the coelacanth and the horseshoe crab, both of whom are often referred to as living fossils.  In this context, I'm using the term loosely, as H. floresiensis is no longer alive today.  Instead, I am referring to the fact that at the time H. floresiensis was alive, it might have been considered a living fossil.

**If that didn't ruin that movie for you, keep in mind that Indiana Jones is irrelevant to the outcome of Raiders of the Lost Ark, and that Luke and Leia are siblings and made out.


Works Cited:

23-Fact Tuesday: Strange Evolution of the Wild Pacific

So the other day, I enjoyed a Discovery/BBC program entitled "Wild Pacific," all about animals and humans in the Pacific.  This episode was entitled "Strange Evolution," and boy, were some of these guys strange!  Let's take a 23-Fact Tuesday look at some of these bizarre creatures!  Allons-y!

1.  The dingiso, a bear-faced, dog-sized tree kangaroo native to the rainforests of New Guinea, only became known to science in 1994, showing that there are still many, many fascinating natural phenomenon that have yet to be discovered by humans!

2.  Prior to the arrival of humans on Hawaii, it has been estimated that only one new species of animal or plant washed up on the shores every 35,000 years!

3.  With few terrestrial predators on the islands of New Zealand, the Fiordland crested penguin has moved from nesting along the shore to nesting within forests, moving along freshwater streams to reach their nests!

4.   The young of the Fiordland crested penguin are, of course, born in the forests.  They don't actually see the ocean (although the nests are usually close enough to hear and smell it) until they are about three months old, at which time they embark on their very first fishing trip: alone!

5.  On the island of Santa Catalina in the South Pacific, local fisherman fish in a simply fascinating fashion: they actually use spider webs from the golden orb spider that are reportedly as strong as kevlar to capture fish whose mouths are too narrow for conventional fishhooks!  Click on the link HERE to watch a short and fascinating video about this!

6.  Prior to human colonization of New Zealand, the only mammals that made it to its shores were bats and marine mammals.

7.  With so few terrestrial predators, one bat, the short-tailed bat, actually spends much of its time on the ground, foraging through the leaf litter, searching for the flightless weta, a relative of the locust.  In order to prevent damage to their delicate wing membranes, the short-tailed bat has developed special sheaths on its wings.  Interestingly, this terrestrial foraging behavior is probably very similar to how the bat's mouse-like ancestors behaved.

8.  The flightless kakapo is the world's largest parrot, and has developed sensitive whiskers on its face in order to help it navigate its way through the dark.  It's nocturnal behavior, as well as its size I would assume, has earned it the nickname "the owl parrot."

9.  The favorite food of the kakapo are the tiny seeds of the rimu tree and, since the bird is flightless, it has developed strong claws to help it climb up into the trees to reach the seeds.  Interestingly, the kakapo only breeds when the trees produce a "bumper crop," which is only about once every four years or so.

10.  Due to this odd cycle of breeding of the kakapo, the bird reproduces less often than almost any other bird.  By contrast, however, it lives longer than most others, sometimes up to 60 years!

11.  During breeding season, the male kakapo makes a "booming" sound to attract a female.  The male booms nonstop each night for 8 hours a night for up to three nights, resulting in thousands of booms.  The wind can carry the booms for up to three miles!  The female, of course, only responds to the males booms if the rimu seeds are plentiful.  Click HERE to check out some footage of the kakapo booming.

12.  LAST KAKAPO FACT, I PROMISE!!  The kakapo was almost hunted to extinction by humans for food and feathers, but they are making a human-assisted comeback now, climbing from only 51 individuals in 1995 to 91 individuals today!  (Possibly more, as I believe the television program is a year or two old or so.)

13.  The Australian brushtail possum was imported by colonists for fur to New Zealand over two centuries ago.  With no natural predators, however, it has spread like a plague, stripping trees of their vegetation.  About 70 million of them are estimated to inhabit the forests now.  That's like 350,000 a year, not including the ones that died.  Holy.  Cow.

14.  Introduced species can cause terrible problems to insular (island) ecosystems.  One of the most extreme examples is thought to be Easter Island, where it has been hypothesized that rats were what did in the colony.

15. For nearly 100 million years, the tuatara and its ancestors have remained almost entirely the same.  During the time of the dinosaurs, the tuatara's ancestors were very numerous, but following their extinction 65.5 MYA, they just couldn't compete, and were slowly extirpated across the globe.  Except in New Zealand, where they still reside today!  Incredibly, the tuatara sometimes can go an entire hour with only one breath!

16.  60 MYA, what is now the island of New Caledonia broke off from Australia, and is now 800 miles from the mainland.  This has allowed its native fauna to evolve in new and fantastic ways: such as the flightless, chicken-sized kagu, the only extant member of an ancient lineage.  HERE we have a fantastic video of this ridiculous bird!

17.  The monkey-tailed skink is the largest skink in the world, and is native to the Solomon Islands, an archipelago of nearly 1,000 tropical islands).  The monkey-tailed skink grows to around 3 ft. in length and weighs around 2 lbs., which is about 1,000 times heavier than the world's smallest skink.

18.  The monkey-tailed skink is an oddity amongst skinks.  Not only is it the largest skink in the world (as we mentioned above), it is also the only skink in the world to have a prehensile tail, which it uses to grasp branches while climbing in trees, assisted by its thick, sharp claws.   This is also an oddity, as most skins are terrestrial (meaning they live on the ground), as opposed to arboreal (which means that they live in the trees).  Furthermore, most skinks are insectivores, while the monkey-tailed skink is mostly vegetarian, consuming the leaves in the trees.

19.  The New Zealand kea, named for its call and native to the southern Alps, is considered to be one of the most intelligent and playful birds in the world.  As a matter of fact, some keas will damage cars out of curiosity!

20.  Up to thirty non-native species arrive on Hawaii every year due to humans, such as the Jackson's chameleon, native to east Africa, which was imported in the 1970s to Hawaii as an exotic pet.

21.  Another biological organism introduced by humans to Hawaii was sugarcane.  Like most places that humans visited, however, they also accidentally introduced rats.  And the rats ate the sugarcane.  Well, the humans who were trying to make a profit off of the sugarcane didn't like that, not one bit.  So, in the hopes of extirpating the rat population, the humans introduced the Indian mongoose.  However, what the humans failed to take into account was the fact that the Indian mongoose is diurnal, or lives during the day....while the rats are nocturnal, and move around at night.  So instead of eating the rats, the Indian mongoose eats the native birds.  Hawaii: 0.  Human Stupidity: A whole lot more than it should be.

22.  The ancestors of the I'iwi, a long billed honeycreeper endemic to Hawaii, were blown to Hawaii about 4 MYA, and looked very different from what they looked like today.  It is thought that they looked something like the Palila, a short billed finch that uses its tough beak to tear open tough seed pods.

23.  The last fact isn't from the program.  It's from "The Song of the Dodo" by David Quammen, one of my favorite books of all time.  It's a quote: "Islands are where species go to die."  He means that islands can be very dangerous places for animals to live.  But now with all the messes humans have introduced, that effect has been exasperated.  Just something to think about.