Komodo dragon, as befits any creature
evoking a mythological beast, has many names. It is also the Komodo
monitor, being a member of the monitor lizard family, Varanidae, which
today has one genus, Varanus. Residents of the island of Komodo call it
the ora. Among some on Komodo and the islands of Rinca and Flores, it
is buaya darat, a name that is descriptive but inaccurate; monitors are
not crocodiles. Others call it biawak raksasa (giant monitor), which is
quite correct; it ranks as the largest of the monitor lizards, a
necessary logical consequence of its standing as the largest lizard of
any kind now living on the eart. Within the scientific community, the
dragon is Varanus komodoensis. And most everyone calls it simply the
Komodo.” Claudio Ciofi.
The Komodo dragon is an ancient species
whose ancestors date back over 100 million years. The Varanid genus
originated between 25 and 40 million years ago in Asia. The Komodo
descended from this species and evolved to its present form over four
million years ago.
The Komodo is long lived as are most of
the larger reptilian species with an estimated life expectancy of over
50 years in the wild. In keeping with its longevity, the Komodo matures
late in life, becoming sexually viable at five to seven years, and
achieving maximum body density in fifteen years. Komodo dragons are
sexually dimorphous, which means males are bigger than females. The
largest recorded specimen was 3.13 meters in length and was undoubtedly a
male. Females rarely exceed 2.5 meters in length. What is perhaps more
important, is that the characteristic bulk is achieved by older dominant
males in clearly delineated territorial areas. As an adult Komodo can
consume up to 80% of its body weight in one gorging, weight is a highly
variable factor, and is largely dependent on the most recent feeding. A
typical weight for an adult Komodo in the wild is 70 kilograms.
Komodo dragons are first and foremost
opportunistic carnivores, and predators second. Although the Komodo can
sprint briefly at 20 kilometers an hour, it does not chase down game as
do the larger mammalian predators. The Komodo is a stealth predator,
which lies motionless and camoflouged alongside game trails for the
unwary, which tend to be the very young, the old and the infirm. In an
attack, the Komodo lunges at its victim with blinding speed and clasps
it with the serrated teeth of the jaw. Prey are rarely downed in the
initial attack unless the neck is broken or ceratoid artery severed. The
more likely outcome is escape, followed by death a few hours or days
later from septicemia introduced by the virulent strains of bacteria
found in the saliva of the Komodo dragon (the Komodo survive primarily
on carrion and ingest the bacteria when feeding).
The Dragons has two highly developed
sensory organs – the olefactory and the Jacobson’s – which allow the
dragon to detect rotting carcasses from distances as great as 10
kilometers. The yellow forked tongue is constantly being flicked in and
out of the mouth, “tasting the air”, and inserted into the Jacobson’s
organ located in the roof of the mouth. The individual tips are highly
sensitive and are capable of discriminating odors in the magnitude of
millionths of a part. Using the information garnered, the dragon wends
in a seemingly random, winding path which becomes straighter the closer
it approaches to the carrion.
The Komodo is typically a communal
feeder and any number of dragons might arrive at the site of the
carcass. Socialization occurs during feeding at carrion sites, as does
mating. The abdomen is slashed first and the intestines and stomach
contents scattered. Young juveniles roll in the fecal matter to mask
their scent from aggressive adults, which attack and sometimes kill
juveniles during feeding. The dominant male feeds until sated, followed
by other dragons in order of size. While the dominant male is gulping
down hindquarters and ribcages, the braver dragons chance foraging a few
scraps. Virtually the entire carcass is consumed in the process– head,
fur, hooves and bones. After feeding, the Komodos become quiescent and
approachable while their digestive tracts are converting the food into
fat energy stored in the tail.
Between the months of May and August,
mating occurs at and around feeding sites. As males outnumber females in
a ratio of nearly four to one, the dominant male must fend off other
suitors before mating. Males will engage in slashing, biting and
bipedular rearing onto the tail, until the dominant male is acknowledged
by displays of subservience and the vanquished flees. The female is
forced into a prone position while the male tongue flicks her body, and
in particular, the fold between the torso and the rear leg close to the
cloaca. With Komodos, the male hemipenes are located here as are the
female genetalia. Once prone, the male mounts onto the back of the
female and inserts one of the two hemipenes into her cloaca , depending
on which side he is perched. The month of September is when a clutch of
15-30 eggs is buried in a nest dug with the powerful claws of the female
dragon. A typical nesting site is in the composting vegetative mounds
of the maleo birds which are indigenous to Komodo.
The gestation period for the eggs is
eight to nine months. Hatching, which average 40 centimeters in length
and weigh 100 grams, emerge from the nest in April and immediately
scramble up the nearest tree to avoid being eaten by the adults. There
are plenty of small lizards, insects and mammals in the canopy after the
brief rainy season in January and February to sustain the juveniles
until they descend to the forest floor roughly a year later. This period
of change between an arboreal and a terrestrial habitat, when the
juveniles are a meter in length, is a time fraught with danger. The
juvenile Komodo is just too bulky to safely ascend many trees, and not
big enough to outrun a ravenous and determined adult. Cannibalism is a
fact of life for this species, and perhaps is an evolutionary response
to the harsh, arid climate of Komodo.
Prey species for the dragon on Komodo
island include deer, boar, wild buffalo, the Maleo bird, snakes,
reptiles and small mammals. On Rinca, the monkeys and wild horses found
there are also constitute prey, as do the goats raised by the local
people. On the odd occasion people are also attacked by the Komodo
dragon. There have been eight recorded instances of attacks on humans
since Komodo has become a national park, almost all of which occurred on
Rinca.
