“This year, a study titled Fine dining or fortress? Functional shifts in spider web architecture by the western black widow emerged from the University of Akron campus. The study was conducted by Dr. Todd Blackledge, along with two UA biologists, graduate students Jaquelyn Zevenbergen and Nichole Schneider.””
This year, a study titled Fine dining or fortress? Functional shifts in spider web architecture by the western black widow emerged from the University of Akron campus. The study was conducted by Dr. Todd Blackledge, along with two UA biologists, graduate students Jaquelyn Zevenbergen and Nichole Schneider. The study served as Zevenbergen’s master thesis and provides insight into the advanced nature of spiders. The study ultimately concluded that spiders are able to construct webs based on their needs for survival.
Blackledge, a professor at the University of Akron, has been working with spiders for 14 years. He was lead in this direction when he noticed that spiders seemed to have the ability to assess their need for food. In a previous study, we had found that black widow spiders would make a radical change in how they spun webs, based on how successful they had been at catching food. Starved spiders would spin a web with a very different shape that contained specialized structures called ‘sticky gumfoot threads’ that well-fed spiders didn’t put into their webs, Blackledge explained.
Through experimentation, the biologists gained an understanding of why spiders were making these changes.
We thought that starved spiders should be spinning webs that are designed to better catch prey, because that’s what they need to survive. Well-fed spiders don’t need extra food, but they may need to protect themselves from predators and the environment … so they may be shifting the shapes of their webs to basically be a better defense for them, Blackledge said.
The biologists tested this hypothesis by seeing how effective spiders were at catching prey while hunting on different kinds of webs. This research was conducted at a field station in the Bath Nature Preserve. At this station, the scientists would starve and feed spiders to observe the differences their state of hunger created in their webs. Since spiders hunt at night, the team used infrared video cameras to monitor the spiders.
To test the functionality of the fortress variation of web, the experiment called for interaction between a predator and the spiders. After some investigation, the team realized that the primary predator in their experiment, a type of mud-dauber wasp, does not prey on cobweb spiders. They sense a cobweb, and they just fly away, Blackledge said. This came as a surprise since this wasp was largely thought to be a predator of these spiders. So for now, the question of the effectiveness of different webs remains unanswered.
The hypothesis that spiders were making adaptive changes to the shapes of their webs was proven to be true. People didn’t realize that web-spinning behaviors were quite so sophisticated [or] that spiders could respond to the environment in such different ways, Blackledge said. I think it’s a great example of some of the research that the students of the biology department are conducting, he later added.
More information on this study can be found at www.sciencedirect.com
“” #1.1360929:3012818587.jpg:20080916_spiders1_db-edit.jpg:One of Blackledge’s spiders being fed. He has been studying the spiders for 14 years.:Diana Ball”