Featured Research

from universities, journals, and other organizations

Colugos glide to save time, not energy

Date:
July 28, 2011
Source:
The Journal of Experimental Biology
Summary:
Everyone has always assumed that animals glide to save energy, but when researchers attached acclerometer/radio transmitter back packs to colugos in the Singapore rainforest, they discovered that colugos use 1.5 times more energy gliding than they use scampering over the same distance. Instead of saving energy, the animals saved time, which they could use for foraging.

Colugo in a tree.
Credit: pwollinga / Fotolia

Gripping tightly to a tree trunk, at first sight a colugo might be mistaken for a lemur. However, when this animal leaps it launches into a graceful glide, spreading wide the enormous membrane that spans its legs and tail to cover distances of up to 150m. So, when Greg Byrnes and his colleague Andrew Spence from the University of California, Berkeley, were looking around for a mammal to carry the accelerometer/radio transmitter backpacks that the duo designed to track animals in the field, the colugo was an obvious choice.

"They are a large glider and it was an opportunity to learn about an animal that we didn't know much about," says Byrnes. Admitting that they were initially interested in the natural history of these charismatic creatures, Byrnes realised that they could use the information gathered to find out about the cost of the colugo's gliding lifestyle. Flying to Singapore, Byrnes teamed up with Norman Lim to track the gliding mammals and the team discovered that instead of saving energy, colugos glide to save time. Their discovery is published in The Journal of Experimental Biology.

Describing how some of the nocturnal colugos roost low in the forest, Byrnes was able to capture six of the mammals and glue the accelerometer packs to their backs before allowing them to scurry back up their trees for their first glide of the night. Explaining that the data loggers were able to collect data for 3-9 days, Byrnes and Lim tracked the animals until the data loggers eventually fell off and they were able to retrieve them several weeks later.

Back in Berkeley, Byrnes, Spence and Thomas Libby had the unenviable task of managing the colossal amount of data collected: "We were sampling at 100Hz for days," explains Byrnes. According to Byrnes, there is a distinctive acceleration profile when they glide. "What you see is the leap and the landing when there is this sweeping acceleration, so it's easy to pick out their glides," he says. Eventually, the trio converted each animal's acceleration traces into velocities -- as they scaled trees and glided -- and then they calculated the distances that the animals covered.

Analysing the glide trajectories, the team realised that the colugos only climb a relatively small height to achieve their lengthy shallow glides. "The average was 8 m for an animal that is gliding 30-50m," says Byrnes. But how much energy were they using to cover that distance?

Basing their calculations on the amount of energy used by small climbing primates -- close relatives of the colugo -- the trio calculated the energy used by a colugo ascending a tree to initiate a glide. Then they calculated the amount of energy that the animals would use if they had clambered through the canopy to cover the glide distance and were amazed to see that instead of saving energy, the colugos were using 1.5 times more energy. "This was a surprise, as the dogma has always been that gliding is cheaper," says Byrnes.

However, one thing was clear: gliding was faster. "If you watch the animals move through the trees they move pretty slowly," says Byrnes, "But they can go 10 times as fast and cover long distances gliding so they can spend more time foraging," he explains. Gliding could also protect colugos from dangerous predators and reduce the risks of climbing on spindly branches, so it could be more of a long-term benefit than simply saving energy


Story Source:

The above story is based on materials provided by The Journal of Experimental Biology. The original article was written by Kathryn Knight. Note: Materials may be edited for content and length.


Journal Reference:

  1. Greg Byrnes, Thomas Libby, Norman T.-L. Lim, Andrew J. Spence. Gliding saves time but not energy in Malayan colugos. Journal of Experimental Biology, 2011; DOI: 10.1242/%u200Bjeb.052993

Cite This Page:

The Journal of Experimental Biology. "Colugos glide to save time, not energy." ScienceDaily. ScienceDaily, 28 July 2011. <www.sciencedaily.com/releases/2011/07/110728082546.htm>.
The Journal of Experimental Biology. (2011, July 28). Colugos glide to save time, not energy. ScienceDaily. Retrieved September 19, 2014 from www.sciencedaily.com/releases/2011/07/110728082546.htm
The Journal of Experimental Biology. "Colugos glide to save time, not energy." ScienceDaily. www.sciencedaily.com/releases/2011/07/110728082546.htm (accessed September 19, 2014).

Share This



More Plants & Animals News

Friday, September 19, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Elephant Undergoes Surgery in Tbilisi Zoo

Raw: Elephant Undergoes Surgery in Tbilisi Zoo

AP (Sep. 18, 2014) Grand the elephant has successfully undergone surgery to remove a portion of infected tusk at Tbilisi Zoo in Georgia. British veterinary surgeons used an electric drill to extract the infected piece. (Sept. 18) Video provided by AP
Powered by NewsLook.com
Chimp Violence Study Renews Debate On Why They Kill

Chimp Violence Study Renews Debate On Why They Kill

Newsy (Sep. 17, 2014) The study weighs in on a debate over whether chimps are naturally violent or become that way due to human interference in the environment. Video provided by Newsy
Powered by NewsLook.com
Some Tobacco Farmers Thrive Amid Challenges

Some Tobacco Farmers Thrive Amid Challenges

AP (Sep. 16, 2014) The South's tobacco country is surviving, and even thriving in some cases, as demand overseas keeps growers in the fields of one of America's oldest cash crops. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

AFP (Sep. 16, 2014) Scientists say a female colossal squid weighing an estimated 350 kilograms (770 lbs) and thought to be only the second intact specimen ever found was carrying eggs when discovered in the Antarctic. Duration: 00:47 Video provided by AFP
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