Texas’ wildlife and wild places can use all the friends they can get. Many of our citizens are in the grip of “nature deficit disorder,” and so the best friends nature can have are those who like science and natural history. Luckily, there is a cadre of people who study nature in Texas, who like nothing better than spending time immersed in it, and volunteer to support it. Who are these ecological illuminati? They are Texas Master Naturalists, an organization with 42 chapters in Texas and over 8,000 trained volunteers. Last Tuesday I spent the better part of three hours with the incoming group of Cross Timbers Master Naturalists, teaching their herpetology class. We followed up yesterday with a brief walk at the edge of the marsh and in the bottomland forest at Fort Worth Nature Center & Refuge.
We started at the marsh boardwalk, expecting to find a few frogs and a basking turtle or two. Sure enough, I quickly spotted a green treefrog on a reed stalk. Adhering to the stalk like a lime-green lump, it stayed motionless as the group of us pointed, took photos, and talked about this beautiful little amphibian. I encouraged the group to take any opportunity they could get to listen to a springtime breeding chorus of these frogs at night. Hundreds of eagerly “quacking” male green treefrogs at close range in the darkness is a slightly overwhelming and oddly beautiful experience.
We also spotted a couple of young American bullfrogs, sitting on the mud beside the water and so marvelously matching the color of mud and algae that they were hard to spot without looking for the outline of the body and the two eyes scanning the area for insects to eat and for any approaching watersnake or heron with a taste for bullfrog. While adult bullfrogs may reach up to eight inches in snout-vent length (that is, not counting the legs), these may have emerged from tadpole stage earlier this year. Some were only a couple of inches in snout-vent length.
The second group was treated to a glimpse of a western coachwhip as we left the boardwalk area. It took off within a small group of trees and greenbriar and I followed as quickly as possible, but these snakes are fast and agile as they thread their way through downed branches and greenbriar tangles. We lost it where a small log lay in the leaf litter, and did not see it again although I had people position themselves around the perimeter (watching for a “back door” escape), I used the snake hook to move the log, and we scanned the branches of surrounding trees. Perhaps it had already slipped away before we could get in position, or maybe a cavity where roots had rotted away provided it a deeper refuge. I love these slender, four or five foot harmless snakes. They are among the fastest and most agile of Texas snakes, and they have big, bright eyes and a tendency to “periscope” up to look around in curiosity.
We then walked into the bottomlands near the marsh. Here was a chance to see cottonmouths, watersnakes, frogs and toads, skinks, and other herps. Not that I expected we would hit the jackpot and see all these things, but we had a great chance to see some of them. Every herp trip is a roll of the dice, and in a big patch of habitat you can only turn a few of the logs and examine a small sample of leaf litter and tree trunks. Every additional hour and each new acre of habitat increases your odds of finding things. As it was, we saw a series of toads ranging from a tiny toadlet to a small adult Gulf Coast toad. We talked about the difficulty of identifying toadlets, while every millimeter of additional growth makes a pattern a little more apparent, cranial crests a bit more visible, and the shape of parotoid glands more apparent.
Someone in the first group noticed a little wiggle in the leaf litter, and that wiggle belonged to our smallest skink, the “little brown skink” (an unimaginative but accurate name). These two-toned brown to slightly coppery-colored lizards have small legs, long bodies, and almost seem to swim through decaying leaves and soil. I will never forget its description, in the Conant & Collins field guide, as an “elfin reptile of the woodland floor.” It took me several tries, using care not to break the tail of this subadult skink, before I had it in hand for closer inspection by the other participants.
Elsewhere in the bottomlands, there were many invertebrate treasures to find. Someone found a luna moth that had finished its short adult life and fallen to the ground. Luna moths are always a beautiful and special treat with their pale green wings, the hindwings gracefully trailing behind in an adaptation that I understand is designed to fool bat radar. And spiders had spun webs between branches everywhere. Especially common were the spiny orb weavers, little spiders with flattened abdomens and spines projecting around the edges (in the larger female spider). Sitting in the center of their orb-shaped webs, the spider can look like a small thorny seed that has become stuck in the web.
I try to navigate through places like this with some care not to run into the webs. As a child, I had put my hand down a small burrow in the back yard and brought up a tarantula, and the experience was badly frightening. I had a severe spider phobia for some time, but in later childhood when I hung out with biologists at the Fort Worth Children’s Museum it became apparent that in order to pursue field biology, I would have to tolerate a certain closeness with spiders. The field trips were a sort of “exposure therapy,” which is actually the most effective treatment for phobia, and I came to have a certain appreciation for these arachnids – but I stop short of handling them and certainly don’t want to become entangled in their webs! When this happened a couple of times during our walk, I managed not to squeal like my former eight-year-old phobic self, but it sure was not the high point of the outing.
We were careful not to indiscriminately damage rotting logs, but those we rolled over or examined often contained bess beetles. I took a photo of one that was reddish-brown rather than black, and texted it to Clint, who identified it as a just-metamorphosed bess beetle whose chitin would soon harden and turn black. BugGuide says that these beetles live in family groups in galleries within the rotted logs that they eat. Adults take care of the larvae and feed them pre-chewed wood.
It seems like the ideal herp trip is one in which there are folks who know about and can interpret many aspects of the natural world, even if you aren’t finding a whole lot of herps. This little trip was enjoyable both for the herps we found as well as for the fascinating invertebrates, the giant cottonwoods, and all the other life of the bottomland forest. “Thank you” to the incoming Cross Timbers Master Naturalists, for making this a shared learning opportunity!
Conant, R., & Collins, J.T. (1998) A field guide to reptiles and amphibians, eastern North American (3rd Edition). NY: Houghton-Mifflin.