Wild Ideas: Size is relative

Recently I ran into three different species in two days that were all about three inches long, but my response to them reminded me that size is relative.

Deep in our “reptile brains,” we store our atavistic fears from when we were small things being hunted by large things. Big can scare us. We tend to find small animals “cute.” This is especially true of young things. As highly social primates, we are hard-wired to want to be nice to cute little things, such as human babies, as our species depends on shared interest in caring for our young.

A juvenile red-spotted newt, known as a red eft in this stage of its life, warms itself in the early morning sun on the Hazel River Trail.Pam Owen | Rappahannock News
A juvenile red-spotted newt, known as a red eft in this stage of its life, warms itself in the early morning sun on the Hazel River Trail.

Of the small species I encountered recently, the first was undeniably the cutest — a red eft. I found one of these amphibians, a common sight in Appalachian forests, on the Hazel River Trail in Shenandoah National Park. It was early in the morning, with not much sun along the trail, but this little critter had found a small patch of sunlight to get his amphibian metabolism going to the point where he could get on with his day.

Red efts are juvenile red-spotted newts (Notophthalmus viridescens viridescens), which spend that part of their lives in the forest. When they become adults, they return to water to breed and stay there. I hunkered down next to the eft to get a closer look, which is easy to do when its metabolism is running this slowly. Red efts are not only tiny but also soft, pretty, slow moving, without discernable defenses and nonaggressive — just plain cute.

This enormous (but harmless) fishing spider, more than three inches long from “toe to toe,” surprised Pam Owen in her home. Pam Owen | Rappahannock News
This enormous (but harmless) fishing spider, more than three inches long from “toe to toe,” surprised Pam Owen in her home.

My response was different to my next encounter with a creature of roughly the same size as the eft. I was lying down on the couch to settle into a baseball game and caught movement about six inches from my face. I turned my head to find myself eye to eye (actually two eyes to eight) with the biggest spider I’ve even seen in Virginia as it crawled out of the cushions and headed for me. I jumped up, muttering a lot of interjections, starting with “jeez,” “wow” and adding a few others as I was trying to wrap the non-reptilian part of my brain around what I was seeing.

When it comes to nature, I’ve always had a soft spot for creepy crawlies, the creepier the better. But I’m also human, and (relatively) large, hairy critters that are suddenly in my face can still get my adrenal glands pumping. As soon as I totally grasped what was going on, I realized this arachnid was no threat. It was a harmless Dolomedes tenebrosus (dark fishing spider). They are quite common here, and I’ve observed and photographed them often — but none this big.

I got up, grabbed my bug jar and trapped the spider. Its size and fat body cued me into its gender — female. I kept complimenting this bodacious gal as I put her it into a larger glass bowl to take a few photos of her next to a quarter, for scale, and measure her. Her body alone was 1.25 inches long, 20 percent beyond the “normal” maximum length for this species; adding in the legs, she was roughly the same length as the newt, about three inches.

When I was done, I thanked the spider for livening up my day and released her next to a large boulder bordering one of my garden patches. She scampered up its face as I took several more photos. I then left her alone to hunt, hoping I’d get to see her again — and maybe even her young. Perhaps an entire dynasty of huge fishing spiders would fill my yard. How cool would that be!

Despite its large size, this gray petaltail dragonfly blends in well with the tuliptree stump on which its perched.Pam Owen | Rappahannock News
Despite its large size, this gray petaltail dragonfly blends in well with the tuliptree stump on which its perched.

Later on the day I saw the spider, my landlady called me down to her house to see a dragonfly. When I arrived, it was flying around in her yard, alighting briefly on several objects, including my right leg at one point. It eventually settled onto a tuliptree stump, where I could observe it better and take some photos.

This was a behemoth when it comes to dragonflies, with a stocky body (again about three inches long) that had a rough surface. Clear wings, with fine black lines outlining each section, sprouted from the large, humped thorax. The dragonfly’s head was also proportionately large, with the bulging eyes typical of its insect order (Odonata). When I looked closer, I found subtle, cream-colored rectangles along its otherwise gray body. With its coloring, it blended into the tree stump, despite its size. In later searching my guides later, I determined it was gray petaltail (Tachopteryx thoreyi).

So size is relative. Big does not necessarily scare us; surprisingly big can. Stories of people seeing 600-pound black bears are repeated over and over, but how many people keep talking about seeing a 200-pound one going about its business? The same goes for small animals. While three inches is on the small size for a salamander, it’s huge for a spider or dragonfly here in Virginia.

And, of course, size isn’t the only factor in determining the potential threat posed by an animal. We tend to find creatures that are soft and pretty, like the red eft, much less threatening than big, hairy spiders or rough-looking dragonflies with huge eyes. While all three of these species are actually efficient hunters of a variety of smaller animals, the spider and dragonfly look more like the fierce predators they are. But, despite its gentle looks, the red eft is not harmless. It carries in its skin toxic and noxious secretions to ward off other predators, including high concentrations of a neurotoxin and strong emetic (which causes vomiting) that can be dangerous if consumed.

No matter their size, or whether we find them cute or scary, all three of the marvelous creatures I encountered that week play an important role in our ecosystems, and it was a treat to see them. (I’m still telling everyone about the spider and dragonfly —  not so much the red eft.)

© 2015 Pam Owen

 

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