Hard life for female Komodo dragon

Source: eurekalert.org
The average life span of the female Komodo dragon is only half of that of her male counterpart. A research team concludes that this may be a result of the heavy physical labour necessary to produce and protect her offspring.
For ten years, an international research team (from universities in Australia, Indonesia and Italy) monitored 400 Komodo dragon individuals in their original habitat. This data was used to produce a model of the growth and life of the species.

Komodo dragons are the largest lizard species. They prey on large animals, including water buffalo, deer and wild pigs; they have also been known to kill humans.

Male Komodo dragons, on average, age to about 60 years old, having grown to approximately 160 cm in length and reached a weight of 65 kg. Females live an average of 32 years, and are smaller than the males: not longer than 120 cm and less than 22 kg. The huge difference in life expectancy surprised the researchers. The difference in age and size seems to be related to the enormous amount of energy the female spends on building nests, laying eggs and guarding them. This guarding is especially energy intensive: it can take up to six months, during which the females eat almost nothing. During this time the female loses a great deal of weight and condition.

The animals grow at the same rate until they reach sexual maturity around the age of seven. Females’ growth then slows and doesn’t continue as long, and they die younger. The research team was interested in gaining more insight into the development and life of this protected species. The early death of the females may increase the competition among males.

The results of the investigation and the growth model have been published in the journal PLoS One.