The long, hot day was surrendering to darkness at the preserve. The trees and shrubs around the edge of the pond were black silhouettes and the sunset was fading. Shades of gold and rose would soon slip into the dusty gray-black that passes for night sky in a big city whose lights perpetually fight the darkness. We had listened to frog calls and scanned the pond margin with flashlights to look for frogs or a watersnake beginning its nightly hunt. In that last rosy light above the pond, things were dipping and flying, feeding on the insects that buzz around the water. Some of the acrobats had the strong, angular wings of swallows, birds whose flying maneuvers are amazing. But then we noticed that others had stubbier outlines with more flapping. Bats! It was not surprising to find them, but since I rarely get a chance to actually observe them, it was a wonderful treat!
This walk was part of what is becoming a survey of the reptiles and amphibians (“herps”) of the 59-acre preserve, with incidental observations of whatever else we find. I plan to visit the place every week, with walks that include trails through primarily wetland, woodland, and open or “edge” habitat where meadows or glades open up in the Cross Timbers forest. We will note the time of day as well as temperature, humidity, and sky conditions. Over time, we will have looked for herps in each of these habitats at least once a month, as the seasons change and hopefully as the years roll by. Could we glean some information about whether things are changing? I hope we can offer some educated guesses. The survey is a citizen-science effort by people who are not trained researchers, but what we record can be valuable.
On this particular evening, “we” were Jim Domke, Annabelle Corboy, and me. Jim is a newspaper guy, and now a freelance writer and photographer. He writes about nature and cares a lot about the preserve; Jim is the guy who always brings a trash bag to help clean the place up while hanging out with nature nerds. Annabelle is a retired IT person who is now part of Friends of Southwest Nature Preserve. She is a curator for the preserve’s project at iNaturalist and is a great advocate for the citizen science efforts that help document the plants and animals at the preserve.
We started our survey visit on the trails at the edge of the big pond. The shoreline is dotted with cattails, the occasional willow, and plenty of water primrose along the edge of the water. In that tangle of primrose and other low plants, Blanchard’s Cricket Frogs hopped and then disappeared against the dark mud or dove under the water and tangled plant matter. As I watched for a chance to take a photo, a disturbance in the water caught my eye. An adult common Snapping Turtle had come up for air but pulled back down upon seeing me. There was no time for a photo, but that face was unmistakable – the chunky head, the almost-smiling jaws, and those yellow-green eyes with the dark dashes radiating out from the pupil to break up the pattern. In a moment, it was gone, but I was delighted since this was the first common snapper I had seen at the preserve.
That illustrates one reason for doing this kind of survey – to confirm observations of infrequently-seen species. People have reported sightings of the Snapping Turtle at the preserve three times in three separate years. It is very plausible that Snapping Turtles keep to themselves under the water and simply are not seen very often. More observations of them would help to confirm whether a stable population of this species is living in the ponds at the preserve.
Other turtles such as the Red-eared Slider are common in those ponds, and we observed a big female being pursued by several smaller turtles, presumably males courting her. The frequency with which this species is documented, including individuals of different ages (I recently photographed a baby at one of the ponds, and we see half-grown individuals as well as big females and old melanistic males) strongly suggests a healthy reproducing population. And they manage this despite heavy predation on their nests. At the next pond we visited, we saw three excavated turtle nests with broken, dried eggshells. Chances are good that female sliders wandered away from the water until they found a suitable spot, dug nests and deposited eggs, and then covered them with soil and a wish for good luck. Nevertheless, predators such as raccoons are avid nest-raiders and help themselves to turtle eggs, over-easy. I don’t know what the odds are for a turtle nest to successfully incubate and hatch at the preserve, but clearly it is a roll of the dice.
Along the way, there are many other species to see. I photographed a number of grasshoppers such as the big Differential Grasshopper in vegetation around the first pond. That and the delicate little Forktail Damselfly and the orb-weaving spider whose web shone brightly in the flashlight beam all made our walk richer, but none of us are invertebrate experts, and so we added them as incidental observations. The same is true with plants, although Annabelle and I were delighted by the Halberd-leaf Rosemallow that we photographed at the smallest pond. Annabelle knows a good bit about plants, but it would take a dedicated team to systematically survey the plants at the preserve.
We ended up walking most of the way around the pond at the north end of the preserve, and as I mentioned, it was rapidly becoming dark. We spent five minutes monitoring any frog calls, standing quietly with flashlights off. Blanchard’s Cricket Frogs began calling with their quick little “clicks,” sounding like two pebbles being hit against each other. There is a system for grading how many frogs of a given species are calling. This evening, the “call index” for these cricket frogs was a “2,” meaning that multiple individuals were calling and their calls overlapped some, but it was still possible to count how many frogs were calling.
It had been an interesting two hours, with the exciting observation of the Snapping Turtle, then finding the raided turtle nests, and that last leg of our visit with bats, swallows, and frog calls. We heard a Chuck Will’s Widow with its high, whistling call in the distance. I can’t wait to come back for another visit!