Featured Research

from universities, journals, and other organizations

Moa's ark: Why the female giant moa was about twice the size of the male

Date:
April 9, 2013
Source:
Zoological Society of London
Summary:
The evolutionary reason for the massive difference in size between male and female giant moa -- the extinct giant birds of New Zealand -- has been revealed for the first time.

Sir Richard Owen with skeleton of Dinornis.
Credit: Copyright ZSL

Some of the largest female birds in the world were almost twice as big as their male mates. Research carried out by the Zoological Society of London (ZSL) shows that this amazing size difference in giant moa was not due to any specific environmental factors, but evolved simply as a result of scaling-up of smaller differences in male and female body size shown by their smaller-bodied ancestors.

Related Articles


The paper is published April 10 in Proceedings of the Royal Society B.

In an environment lacking large mammals, New Zealand's giant moa (Dinornis) evolved to be one of the biggest species of bird ever, with females weighing more than two hundred kilograms -- the same as about 3 average sized men.

Male and female birds often show differences in body size, with males typically being larger. However some birds, like many ratites -- large, flightless species such as emus and cassowaries -- are the opposite, with the females towering over the males.

Moa were huge flightless ratites. Several different species inhabited New Zealand's forests, grasslands and mountains until about 700 years ago. However, the first Polynesian settlers became a moa-hunting culture, and rapidly drove all of these species to extinction.

Dr Samuel Turvey, ZSL Senior Research Fellow and lead author on the paper, says: "We compared patterns of body mass within an evolutionary framework for both extinct and living ratites. Females becoming much larger was an odd side-effect of the scaling up of overall body size in moa.

"A lack of large land mammals -- such as elephants, bison and antelope -- allowed New Zealand's birds to grow in size and fill these empty large herbivore niches. Moa evolved to become truly huge, and this accentuated the existing size differences between males and females as the whole animal scaled up in size over time," Dr Turvey added.

Future research should investigate whether similar scaling relationships can also help to explain the evolution of bizarre structures shown by other now-extinct species, such as the elongated canines of sabretoothed cats.


Story Source:

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


Journal Reference:

  1. V. A. Olson, S. T. Turvey. The evolution of sexual dimorphism in New Zealand giant moa (Dinornis) and other ratites. Proceedings of the Royal Society B: Biological Sciences, 2013; 280 (1760): 20130401 DOI: 10.1098/rspb.2013.0401

Cite This Page:

Zoological Society of London. "Moa's ark: Why the female giant moa was about twice the size of the male." ScienceDaily. ScienceDaily, 9 April 2013. <www.sciencedaily.com/releases/2013/04/130409211939.htm>.
Zoological Society of London. (2013, April 9). Moa's ark: Why the female giant moa was about twice the size of the male. ScienceDaily. Retrieved January 26, 2015 from www.sciencedaily.com/releases/2013/04/130409211939.htm
Zoological Society of London. "Moa's ark: Why the female giant moa was about twice the size of the male." ScienceDaily. www.sciencedaily.com/releases/2013/04/130409211939.htm (accessed January 26, 2015).

Share This


More From ScienceDaily



More Plants & Animals News

Monday, January 26, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

How To: Mixed Green Salad Topped With Camembert Cheese

How To: Mixed Green Salad Topped With Camembert Cheese

Rumble (Jan. 26, 2015) Learn how to make a mixed green salad topped with a pan-seared camembert cheese in only a minute! Music: Courtesy of Audio Network. Video provided by Rumble
Powered by NewsLook.com
Water Fleas Prepare for Space Voyage

Water Fleas Prepare for Space Voyage

Reuters - Innovations Video Online (Jan. 26, 2015) Scientists are preparing a group of water fleas for a unique voyage into space. The aquatic crustaceans, known as Daphnia, can be used as a miniature model for biomedical research, and their reproductive and swimming behaviour will be tested for signs of stress while on board the International Space Station. Jim Drury went to meet the team. Video provided by Reuters
Powered by NewsLook.com
Husky Puppy Plays With Ferret

Husky Puppy Plays With Ferret

Rumble (Jan. 26, 2015) It looks like this 2-month-old Husky puppy and the family ferret are going to be the best of friends. Look at how much fun they&apos;re having together! Credit to &apos;Vira&apos;. Video provided by Rumble
Powered by NewsLook.com
Florida Might Legalize Black Bear Hunting

Florida Might Legalize Black Bear Hunting

Newsy (Jan. 24, 2015) A string of black bear attacks has Florida officials considering lifting the ban on hunting the animals to control their population. Video provided by Newsy
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:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

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