Featured Research

from universities, journals, and other organizations

Extreme 'housework' cuts the life span of female Komodo dragons

Date:
October 17, 2012
Source:
University of Melbourne
Summary:
Researchers have found that female Komodo dragons live half as long as males on average, seemingly due to their physically demanding "housework" such as building huge nests and guarding eggs for up to six months.

This is a female Komodo Dragon guarding her nest in Indonesia.
Credit: Tim Jessop

An international team of researchers has found that female Komodo Dragons live half as long as males on average, seemingly due to their physically demanding 'housework' such as building huge nests and guarding eggs for up to six months.

The results provide important information on the endangered lizards' growth rate, lifestyle and population differences, which may help plan conservation efforts.

The Komodo dragon is the world's largest lizard. Their formidable body size enables them to serve as top predators killing water buffalo, deer and wild boar and they have also been known to kill humans.

A research team which included scientists from the University of Melbourne, Australia, Indonesia and Italy studied 400 individual Komodo Dragons for 10 years in eastern Indonesia, their only native habitat. The team then produced a model of the Dragon's growth rate, with results published in the current issue of international journal PLoS ONE.

Males live to around 60 years of age, reaching an average 160 cm in snout-vent length (not including tail) and 65 kg at adulthood. However their female counterparts were estimated to live an average of 32 years and reach only 120 cm in snout-vent length, and 22 kg.

Dr Tim Jessop from the Department of Zoology at the University of Melbourne was a co-author on the study and said that the team were surprised by the significantly shorter lifespan of the female Komodo Dragon.

"The sex-based difference in size appears to be linked to the enormous amounts of energy females invest in producing eggs, building and guarding their nests. The process can take up to six months during which they essentially fast, losing a lot of weight and body condition, he said.

"Males and females start off at the same size until they reach sexual maturity at around seven years of age. From then on females grow slower, shorter and die younger."

The research team was keen to understand the growth rate of the Komodo Dragons as this critical process can indicate how the species prioritises its energy use in lifestyle and reproductive strategies. The results suggest that females have high energy 'costs' for reproduction resulting in their smaller size, whereas to reproduce successfully, males must keep increasing in size.

The results could have dramatic consequences for the endangered species as early female deaths may be exacerbating competition between males over the remaining females, possibly explaining why males are the world's largest lizards.

"These results may seem odd to humans when the life span between Australian men and women differ by five years. But each species has different strategies to pass on their genes. For example humans invest a lot of energy in few children as raising them is very energy intensive, whereas insects will have hundreds of offspring with no input into their rearing."


Story Source:

The above story is based on materials provided by University of Melbourne. Note: Materials may be edited for content and length.


Journal Reference:

  1. Rebecca J. Laver, Deni Purwandana, Achmad Ariefiandy, Jeri Imansyah, David Forsyth, Claudio Ciofi, Tim S. Jessop. Life-History and Spatial Determinants of Somatic Growth Dynamics in Komodo Dragon Populations. PLoS ONE, 2012; 7 (9): e45398 DOI: 10.1371/journal.pone.0045398

Cite This Page:

University of Melbourne. "Extreme 'housework' cuts the life span of female Komodo dragons." ScienceDaily. ScienceDaily, 17 October 2012. <www.sciencedaily.com/releases/2012/10/121017102941.htm>.
University of Melbourne. (2012, October 17). Extreme 'housework' cuts the life span of female Komodo dragons. ScienceDaily. Retrieved September 20, 2014 from www.sciencedaily.com/releases/2012/10/121017102941.htm
University of Melbourne. "Extreme 'housework' cuts the life span of female Komodo dragons." ScienceDaily. www.sciencedaily.com/releases/2012/10/121017102941.htm (accessed September 20, 2014).

Share This



More Plants & Animals News

Saturday, September 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: San Diego Zoo Welcomes Cheetah Cubs

Raw: San Diego Zoo Welcomes Cheetah Cubs

AP (Sep. 20, 2014) The San Diego Zoo has welcomed two Cheetah cubs to its Safari Park. The nearly three-week-old female cubs are being hand fed and are receiving around the clock care. (Sept. 20) Video provided by AP
Powered by NewsLook.com
Chocolate Museum Opens in Brussels

Chocolate Museum Opens in Brussels

AFP (Sep. 19, 2014) Considered a "national heritage" in Belgium, chocolate now has a new museum in Brussels. In a former chocolate factory, visitors to the permanent exhibition spaces, workshops and tastings can discover derivatives of the cocoa bean. Duration: 01:00 Video provided by AFP
Powered by NewsLook.com
Could Grief Affect The Immune Systems Of Senior Citizens?

Could Grief Affect The Immune Systems Of Senior Citizens?

Newsy (Sep. 19, 2014) The study found elderly people are much more likely to become susceptible to infection than younger adults going though a similar situation. Video provided by Newsy
Powered by NewsLook.com
Jury Delivers Verdict in Salmonella Trial

Jury Delivers Verdict in Salmonella Trial

AP (Sep. 19, 2014) A federal jury has convicted three people in connection with an outbreak of salmonella poisoning five years ago that sickened hundreds of people and was linked to a number of deaths. (Sept. 19) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins