Nav: Home

Spider sharing isn't always caring: Colonies die when arachnids overshare food

August 04, 2016

Spiders living together in colonies of tens of thousands can go extinct from sharing food equitably, finds new UBC research.

"It's an unfortunate byproduct of what they have to do survive," said lead author Ruth Sharpe, a PhD student in UBC's department of zoology. "It's a puzzle because in this case, evenly splitting resources may not be beneficial to the colony."

This spider species, which goes by the Latin name Anelosimus eximius, lives in South America in colonies of anywhere from one to tens of thousands. Social spiders are found in tropical areas of the world but no other species forms nests as big as Anelosimus eximius. The colonies grow so large because offspring typically remain in the nest they were born in from one generation to the next. They nest together, forming one very large web, and work together when they capture prey like bees, wasps, butterflies, and other insects.

Social behaviour works well for the spiders until food becomes limited, likely because the colony grows too large. Sharpe and UBC zoology professor Leticia Avilés believe the problem occurs because large colonies tend to capture prey that are too large for any one spider to monopolize. Instead, many spiders will take a share and if they cannot capture enough prey, none will get enough food, potentially leading to massive die-offs.

In earlier research, Avilés found that about 21 per cent of established Anelosimus eximius colonies go extinct every generation and that the size of the prey captured increases with colony size.

"We did this research to figure out why large, well-established colonies were going extinct so swiftly," said Sharpe. "Once I saw a massive nest on the side of the road in Ecuador, about five metres tall and four metres across. I went back a few weeks later and it was completely gone."

The study was published this month in the Journal of Animal Ecology.
Watch a video of Anelosimus eximius living together in a nest:

University of British Columbia

Related Spiders Articles:

Researchers find hurricanes drive the evolution of more aggressive spiders
Researchers at McMaster University who rush in after storms to study the behavior of spiders have found that extreme weather events such as tropical cyclones may have an evolutionary impact on populations living in storm-prone regions, where aggressive spiders have the best odds of survival.
Baby spiders really are watching you
Baby jumping spiders can hunt prey just like their parents do because they have vision nearly as good.
Solitude breeds aggression in spiders (rather than vice versa)
Spiders start out social but later turn aggressive after dispersing and becoming solitary, according to a study publishing July 2 in the open-access journal PLOS Biology by Raphael Jeanson of the National Centre for Scientific Research (CNRS) in France, and colleagues.
Spiders risk everything for love
A biology study finds that blue jays can easily spot wolf spiders engaged in their courtship rituals.
Hold the mustard: What makes spiders fussy eaters
It might be one of nature's most agile and calculating hunters, but the wolf spider won't harm an insect that literally leaves a bad taste in its mouth, according to new research by a team of Wake Forest University sensory neuroscientists, including C.J.
More Spiders News and Spiders Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Erasing The Stigma
Many of us either cope with mental illness or know someone who does. But we still have a hard time talking about it. This hour, TED speakers explore ways to push past — and even erase — the stigma. Guests include musician and comedian Jordan Raskopoulos, neuroscientist and psychiatrist Thomas Insel, psychiatrist Dixon Chibanda, anxiety and depression researcher Olivia Remes, and entrepreneur Sangu Delle.
Now Playing: Science for the People

#537 Science Journalism, Hold the Hype
Everyone's seen a piece of science getting over-exaggerated in the media. Most people would be quick to blame journalists and big media for getting in wrong. In many cases, you'd be right. But there's other sources of hype in science journalism. and one of them can be found in the humble, and little-known press release. We're talking with Chris Chambers about doing science about science journalism, and where the hype creeps in. Related links: The association between exaggeration in health related science news and academic press releases: retrospective observational study Claims of causality in health news: a randomised trial This...