Incey Wincey

September 8, 2009 1:35 PM

Are all spiders of the same species equally adept at spinning webs?

Watch any nature documentary about spiders, and you can't help but be amazed at how spiders seem to just 'know' how to spin their webs. But I was wondering - are all spiders as good as each other? For example - some humans seem to have more ability at certain skills than others. Does anyone know if this is also the case with other animals? I would also be interested in the same question for things like birds and their nests.

Note: I know that spiders can get parasites or diseases that affect their nervous system that will mean they are unable to spin webs properly.

posted by Megami to pets & animals (6 comments total)

Are all spiders equally good at building webs? The answer is no.
posted by 517 at 1:54 PM on September 8

Cool. But that is kind of based on learning experience, no? Is it possible to judge if some spiders (seem to be) just inherently better at this web malarky?
posted by Megami at 2:00 PM on September 8

If there was no variation between individuals in a group there could be no natural selection for that trait and web-building is surely evolved behavior. I guess you could quibble about being inherently better or evolving better capacity for learning or more resistance to the disruptive parasites but at that point you are splitting hairs.
posted by Fiery Jack at 2:12 PM on September 8 [2 favorites has favorites]

tl;dr I don't know, but yes, probably.

Do you mean do some spiders have a higher IQ than other spiders?

One could argue that the skill of web weaving is based on genetic memory, and that because of that, there would be variations in the skill because there would be variations in the genotypes among spiders. But thinking of webs as good or bad could be problematic because a good web for one location could be a crappy web for another location. The question is could the spider recognize that their web was crappy. The previous link says that they can, so we would also expect that there would be variations in the ability of a spider to recognize their web as crappy. So a person could probably give a spider an IQ test, in a sense. They place spiders in different environments and test the effectiveness of their webs, find a bell curve, and place a spider into a percentile on the ability to modify their web in response to the environment.

On preview, I'll post this anyway.
posted by 517 at 2:31 PM on September 8 [1 favorite has favorites]

To do this you'd really have to first figure out what is a "good" web and what is not and if experience is a factor rather than innate ability. The link cited talks about the possibility that prey capture is more frequent and requires less effort when a certain species of orb weaver builds a bottom heavy web and, from their discussion, it seems as though the authors think that spiders can learn this strategy with experience.

It would be interesting to take a cohort of spiders raised in identical conditions and somehow aim prey at different areas of their webs over time to see, which, if any, spiders can modify their web strategy slightly to take advantage. You could also damage each spider's web in the same way and see if there is variable success in rebuilding and correlated prey-capture success. Not easy to do, by the way. From experience, throwing prey into a spider's web and getting them to stick is actually sort of difficult... (i used to research spiders...)
posted by hellboundforcheddar at 3:25 PM on September 8

One of the authors of the linked paper was my PhD thesis supervisor. Anyway, I study orb-webs and I find that there is quite a bit of variation, but it depends on what you measure. In nature, the web size for example is affected by the size of the spider. Furthermore, things like the kind of plant support can also affect the shape of the web, but usually not too much. Between individuals there is always going to be some differences, but the template (so to speak) remains very similar.
For my masters thesis, I placed spiders in different sized cages, and spiders in larger cages tended to build larger webs, till they reached a sort of cutoff level.

Another thing: orb spiders that build webs in unprofitable places, where they get no prey, eventually just move to another site. So you can argue that they do learn from previous experience.
posted by dhruva at 6:03 PM on September 8 [2 favorites has favorites]