Pat’s Wildways: Orb-Weaving Spiders

For a change, I jumped out of bed early to head to the beach near the fort in Fort Clinch State Park to catch low tide and to nab a parking spot before all the fossilized shark tooth hunters took up all the room. But, as often happens, I was distracted along the way. The early morning angled light was illuminating sunbeams bursting through the canopy and then, what is that? Up in the trees, a golden orb-weaving spider web was lit up like a Christmas tree ornament, highlighting its yellow color. What a work of art! Nature’s finest!

There are a few species of orb-weaving spiders, but the most often encountered here are these golden orb weavers, sometimes called banana spiders, due to their yellow color and banana shape. They immobilize their prey by stinging them, not by binding them in silk like some spiders do. Yes, they can bite people if tormented, but only then, and their poison has low toxicity to humans. These spiders are large and attractive and are critters to be admired, not feared.

In times of old, I used to see these spiders and their artwork in my own backyard. I’ve examined the intricate webs stretched across open expanses between trees, often with a zigzag design in the web, the stabilimentum. This addition to a web is still not understood by biologists. Is it decoration? A way to stabilize a web? Or a way to attract prey, or to add visibility to keep birds from flying in, or for some other purpose not yet figured out by scientists, but well known to the spider, I am presuming. Sometimes I have found prey items ensnarled in the web, and once I found a much smaller male in a female’s web. He was presumably waiting for his chance to mate with her. Although she might eat him afterwards like some spiders do, the female banana spiders are more gracious and most males survive to mate again.

Sadly, though, there are no more orb-weaving banana spiders in my yard. These most likely disappeared when the area got more developed, pesticides were more commonly used, and many insect populations that fill spider bellies have declined. In my younger days, I also used to see these large orb-weaving spiders during my forays off the beaten track in the woods around us, when I had to carry a stick to clear the webs that were in my path. But now, when I do walk on paths, they are usually well-traveled by other humans before me, and spiders have relocated to places where they are not constantly disturbed.

So, this being said, I was thrilled to see an orb-weaving banana spider illuminated up in the trees above me in Fort Clinch State Park. This started Bucko and me on a search for more spiders from the air-conditioned comfort of our car during our daily rounds through the park. When we started looking for them, there they were, but way above us, with their webs tethered to trees above the reach of cars and pedestrians, looking like they were floating in the sky. We did find one close to the ground beside the road, and photographed it, then kept watch on “Charlotte” for many days, rain or shine, and she was still there.

When something strikes my fancy, like these orb-weaving spiders now, I spend time Googling. It’s amazing what new facts I learn — to share with you. For instance, did you know that orb spider silk is one of the strongest flexible materials on earth, and has been used to make cloth and even bulletproof vests, parachute cords and various medical uses? An orb-weaving spider can produce as many as seven different kinds of silk. But spider silk is difficult and impractical to harvest readily for these uses. That’s where goats come in.

Yes goats! Now, some herds of dairy goats have been genetically modified to produce orb spider silk proteins in their milk. When these goats are milked normally, this milk is strained to remove the spider silk proteins, which are then dried and provided to various industries that use them to develop new products. The goats are otherwise normal, and the milk, sans spider proteins, is just like normal goat’s milk.

And, isn’t that something?

Pat Foster-Turley, Ph.D., is a zoologist on Amelia Island. She welcomes your nature questions and observations. patandbucko@yahoo.com