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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. Komodos 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 caratoid 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 Komodo 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. Hatchlings, 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 terrestial 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. |
