While I was out last night photographing the Estate Find, I grabbed two other images of opportunity and I’ll throw them up now.
I’ve mentioned the explosion of golden silk orbweavers (Trichonephila clavipes) on the property, but they’re getting big now, and I needed an illustration of this. It worked out fairly well, all things considered, and you can see why they’re also referred to as ‘banana spiders.’
Yes, that’s my own hand in the pic, just a little behind the spider so only slightly misleading as to scale. I’d wanted to get this for a while now, and this particular specimen was low enough and within reach, while also being huge. What also worked out well is that there was a large gap through the orb web to the right, likely courtesy of some bird, that I could reach through to put my hand back there. That helped, since the web is nearly a meter across the orb portion, much more if you count all of the anchoring strands. Still, it was close, and the spider jerked in alarm at one point, ensuring that I did too; the arachnophobia that I grew up with is greatly reduced but still not entirely gone, especially when we’re talking this big. This is a female, and if the girth is any indication (not that I’m saying anything,) she’s likely to produce an egg sac soon.
Now, see the brown and white vertical oblong shape, out of focus to the top left? That’s a male in the web (yes, that small,) somehow not cognizant of the fact that he’s way too late to this party. I had to check something on my return, too, since I’d read that there is another spider that often shares the web to steal food, a ‘kleptoparasite,’ but this is not one of them. I’ll have to keep my eyes open since they’re actually pretty cool looking.
For comparison, one of the many newborn Carolina anoles (Anolis carolinensis) that litter the property, taken only minutes afterward.
Yes, not only could the spider take the lizard easily, it might not amount to much more than a snack. Yet the T. clavipes are plainly after insects, albeit large ones, stringing their webs between trees and often sitting quite high in the air. The anoles are unlikely to ever come within range.
Now comes the uneducated speculation, since I started wondering what might prey on the spiders and realized a couple of things. Both the brilliant coloration, which isn’t going to blend in with anything (especially out in the open as they so often are,) and the color of the silk itself would seem to indicate that they evolved to be seen, and the coloration may also be an indication of aposematism, the ‘keepaway’ warning to other species. Typically, this is coupled with some means of discouraging predators, often through being unpalatable, but also through active means; the predator makes the attempt, finds out that this is a bad idea, and remembers the species thereafter because they’re so distinctly-colored. Yes, this means that not only does at least one member of the aposematic species often have to be sacrificed to protect others, but that the predators have to learn this behavior for themselves (since I’ve found no mention of anything inherently/genetically knowing that keepaway colors are bad.) It seems remarkably inefficient, but still better than nothing.
All that said, there’s no mention anyplace that I’ve found that golden silk orbweavers have these colors for such a purpose, and a lot of birds eat spiders – seems like these would be easy pickings. I need to look further into this…