Featured Research

from universities, journals, and other organizations

Spiders Who Eat Together, Stay Together -- And Form Enormous Colony Sizes

Date:
August 9, 2008
Source:
University of British Columbia
Summary:
The ability to work together and capture larger prey has allowed social spiders to stretch the laws of nature and reach enormous colony sizes, zoologists have found.

Social Anelosimus spiders in large colonies will cooperate to capture insects that are much larger than the spiders themselves.
Credit: Image courtesy of University of British Columbia

The ability to work together and capture larger prey has allowed social spiders to stretch the laws of nature and reach enormous colony sizes, UBC zoologists have found.

The findings, published in the Proceedings of the National Academy of Science, may also explain why social spiders thrive in tropical areas but dwindle with increasing latitude and elevation.

“The size of organisms tends to be constrained by a scaling principle scientists call ‘surface to volume ratio,’” says Leticia Avilés, lead author and associate professor in the UBC Dept. of Zoology. While organisms typically have energetic needs proportional to their volume, they must acquire nutrients through their surface. 

“As the organism grows, this surface to volume ratio declines. In a way, this is how nature keeps the sizes of various species in check.”

The same principle may apply to social groups. The surface area of the three-dimensional webs social spiders use to capture prey does not grow as fast as the number of spiders contained in the nests; so number of incoming prey per spider declines with colony size. But Anelosimus eximius, a species of social spider notable for its enormous colony size – some total more than 20,000 individuals – have gained the ability to stretch that law by cooperating and thus capturing increasingly large insects as their colonies grow.

“The average size of the prey captured by the colony increased 20-fold as colony size increased from less than 100 to 10,000 spiders,” says Avilés, who studied the spiders in the wild in Amazonian Ecuador with undergraduate student Eric Yip and graduate student Kimberly Powers.

“So even though the number of prey falls sharply as the colony grows, the biomass that individual spiders acquire actually increases.”

The study also found that large prey, while making up only eight per cent of the colony’s diet, contributed to more than 75 per cent of its nutritional needs.

 “But that only works to a certain point,” says Avilés, who adds that the biomass of prey consumed by the colony peaks when the colony reaches between 500 and 1,000 individuals.

As for the scarcity of social Anelosimus species in higher elevations and latitudes, “there simply aren’t enough large insects in those areas to sustain this type of foraging behaviour,” says Avilés.


Story Source:

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


Cite This Page:

University of British Columbia. "Spiders Who Eat Together, Stay Together -- And Form Enormous Colony Sizes." ScienceDaily. ScienceDaily, 9 August 2008. <www.sciencedaily.com/releases/2008/08/080806113318.htm>.
University of British Columbia. (2008, August 9). Spiders Who Eat Together, Stay Together -- And Form Enormous Colony Sizes. ScienceDaily. Retrieved October 20, 2014 from www.sciencedaily.com/releases/2008/08/080806113318.htm
University of British Columbia. "Spiders Who Eat Together, Stay Together -- And Form Enormous Colony Sizes." ScienceDaily. www.sciencedaily.com/releases/2008/08/080806113318.htm (accessed October 20, 2014).

Share This



More Plants & Animals News

Monday, October 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

White Lion Cubs Born in Belgrade Zoo

White Lion Cubs Born in Belgrade Zoo

AFP (Oct. 20, 2014) — Two white lion cubs, an extremely rare subspecies of the African lion, were recently born at Belgrade Zoo. They are being bottle fed by zoo keepers after they were rejected by their mother after birth. Duration: 00:42 Video provided by AFP
Powered by NewsLook.com
Traditional Farming Methods Gaining Ground in Mali

Traditional Farming Methods Gaining Ground in Mali

AFP (Oct. 20, 2014) — He is leading a one man agricultural revolution in Mali - Oumar Diatabe uses traditional farming methods to get the most out of his land and is teaching others across the country how to do the same. Duration: 01:44 Video provided by AFP
Powered by NewsLook.com
Goliath Spider Will Give You Nightmares

Goliath Spider Will Give You Nightmares

Buzz60 (Oct. 20, 2014) — An entomologist stumbled upon a South American Goliath Birdeater. With a name like that, you know it's a terrifying creepy crawler. Sean Dowling (@SeanDowlingTV) has the details. Video provided by Buzz60
Powered by NewsLook.com
Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-Fuel Impala

Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-Fuel Impala

3BL Media (Oct. 20, 2014) — Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-fuel Impala Video provided by 3BL
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