Giants and dwarfs – a real life fairy tale

Indonesia offers an abundance of reasons to be fascinated by the raw, natural world; tri-coloured volcanic lakes, still-practicing head hunting tribes, flame-furred cousins of men bounding through the jungle. One of the most fascinating biological examples exists here in Flores – Island Gigantism and Insular Dwarfism.

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‘The Island Rule’, developed by J Bristol Foster in 1964, states that insular species, i.e. those found on islands, are prone to size changes throughout the evolutionary process. Large animals have a propensity to shrink in size compared to their mainland counterparts whereas small species grow to giant proportions! As a general rule, carnivores are inclined to become dwarfed and rodents and birds tend towards gigantism.

While there are a number of exceptions and one definitive rule has not yet been developed to explain these size changes, there is a simple rationalization. Species which exhibit dwarfism are often subject to a reduction in food source and therefore possible malnutrition and stunting of growth. Smaller size has advantages such as hiding from predators in a smaller area and the ability to cope with stress better. Gigantism seems to be a direct result of a lack of predators in the island environment. Without threat and with the availability of a constant food source, some species are free to grow beyond their normal realms. Advantages of this are the ability to survive harsher conditions due to higher energy stores, use of intimidation in herbivores which would have used escape tactics previously and larger range and therefore food source.

There are fascinating examples of this all over the world, maybe the most famous being the Dodo – the extinct flightless bird from Madagascar. However, as man has evolved along with the introduction of other predators such as cats and dogs, many of these species no longer exist. Flores, situated within eastern Indonesia, and the many smaller islands surrounding this has an above average amount of giants and dwarfs. Here are a few examples:

Flores Giant Rat - measuring 41–45 cm (1.3-1.5 ft) with a tail length is 33–70 cm, at least twice the size of the more familiar Brown Rat. The Flores Giant Rat can still be found in Flores today, although it is listed on the IUCN Red List as ‘Near Threatened’.
Homo floresiensis – nicknamed ‘The Hobbit’, Home floresiensis co-existed with our species until 12,000 years ago.

Komodo Dragon - is the largest living land lizard at over 3m long. The Komodo Dragon is a rare example of island gigantism in a carnivore and harks back to the dinosaur days when reptiles ruled the world

Flores flightless stork – Remains of this stork that stood at an estimated 1.8m tall were found in the same cave as the Homo floresiensis. Some theories suggest that the two species hunted each other – hobbit vs. stork!

Dwarf stegodonts – Effectively a pygmy elephant which was endemic to Flores until extinction around 12,000 years ago. The smallest of the species had a 300k body weight and was smaller than a water buffalo. There are theories which suggest that the Komodo Dragon grew to such epic proportions by feeding on the stegodonts.

With its lack of any large mammalian predators, Flores was the perfect location for the development of island gigantism and insular dwarfism. The extinction of many of these species seems to coincide with the arrival of modern man and possibly a large volcanic eruption on Bali, although this is yet to be proved.

It is possible to still bring yourself close to these evolutionary marvels. When visiting Flores why not go to the caves where the remains of ‘The Flores Hobbit’ were found, search out the Flores Giant Rat (make sure you bring plenty of cheese) and go searching for Dragons on one of Wicked’s Komodo liveaboard or day trip boats.­­

Check out this BBC article for more info on the Flores Hobbit.
http://www.bbc.co.uk/news/science-environment-22166736

-Wicked Komodo