The Eastern Yellow-Bellied Racer and the Jump to Light Speed

There was once a time when I could chase down an eastern yellow-bellied racer. Well, if it was on a flat surface … maybe if I had a head start. Probably not now, unless my head start was that I was allowed to grab it before it saw me. These snakes are not called “racers” for nothing.

MS-EYBracer

Eastern yellow-bellied racer

They can cruise around on a hot summer day, their big eyes alert to any movement, watching for a grasshopper or lizard to spring into action, and ready to give chase. When they do flush some unfortunate prey animal, they are unrelenting in pursuit. When a big grasshopper lands and freezes, the snake may have to search until it again makes the insect jump, and at that point the chase resumes. Having no venom and no ability to wrap and constrict, the racer simply swallows its prey or maybe pins it on the ground with a section of its body while swallowing. Racers can eat animals as large as a mouse or medium-sized frog, relying on the rows of sharp, recurved teeth and strong jaws to overcome the struggles of its prey.

Many years ago, my family moved to Fort Worth and my knowledge of reptiles and amphibians expanded from days spent hanging out with museum staff and reading books. At the end of the summer, I would occasionally find a little spotted snake around the yard. Their pretty yellow bellies were speckled with rust-colored spots, and as I held them their large eyes looked alert, and their jet-black tongues tested the air. Around the same time, a group of us kids found a medium-sized snake stretched along a branch within a shrub in a neighbor’s yard. It sat motionless, watching us, and I recall it being a sort of olive greenish color. I was puzzled about this snake’s identity but later figured out that it was what some people called a “blue racer,” but down here in Texas it was a different form called the eastern yellow-bellied racer.  With further study, I discovered that the little spotted snakes I sometimes found at the end of summer were actually hatchlings of that same species. Over the course of a couple of years, the spots would fade and the snake would be brownish or olive or grayish-blue on top, and yellow underneath.

MS-juv-EYBracer

A juvenile eastern yellow-bellied racer, probably in its second year, still showing the spotted pattern.

Occasionally I would find one in the field, sometimes as a serpentine blur disappearing in the grass. Other times I might find one under a board or a rock, and if I grabbed quickly, I might get a close look at this muscular coil of pure energy. When grabbed, that same energy is directed toward thrashing and biting, and the poor snake may injure itself if not supported properly. The bites are annoying but not particularly painful, and they seem to come out of nowhere as the snake thrashes around to a new vantage point. However, when gently supported and not harmed, the snake may settle down, after a fashion, continually testing the air with that black tongue and watching its captor like a hawk. Drawing the animal closer, for a detailed look, often results in a strike aimed at the person’s face. Loosening the grip a little too much results in a sudden attempt to break free, as if the racer was waiting for just this opportunity.

Part of the racer’s reputation as a snake that can make the jump to “light speed” is its ability to navigate through brush and around rocks without slowing. Its top speed is actually a little slower that a person could run on a track, but when seen, these snakes are often around rocky outcrops, fallen logs, or tangles of undergrowth, none of which cause the snake to slow down. Imagine the speed with which this reptile processes the visual images coming at it, like a fighter pilot flying low over the landscape, dodging left and right but keeping right on going!

MS-EYBracer-adult – Version 2

Eastern yellow-bellied racer

Eastern yellow-bellied racers make use of a fairly large “home range,” or area within which it hunts, rests, finds water, and so on. In their book, Texas Snakes, Werler & Dixon cite research done in Kansas showing that racers may use about 25 acres as a home range. Within that area, the individual snake may be familiar with refuges such as a particular abandoned burrow or crevice under the rocks, and where the best pools in a little creek may be. These racers prefer open areas such as patches of prairie or savannah, and they may hang around near the edge of a woodland.

Texas has a four other forms or subspecies of racer. The buttermilk racer lives in parts of east Texas, and has the same overall bluish-gray to olive coloration but is speckled here and there with small globs and specks of white. The tan racer, found around the Big Thicket, uses forest habitat much more than the other racers, and is a uniform tan color above and pale whitish below. Along the southern Texas coast, the Mexican racer zips along through the thorn scrub. And at the northeastern corner of the state, the southern black racer is found in several counties.

On a cool, overcast day in March, 2012, I found a young eastern yellow-bellied racer under a big rock in Wise County. I was out with Clint and his wife, and we thought we might get an early start on field herping that year. Sure enough, we did find several things, but everything was under cover, since March in north Texas may turn unpredictably from sunny and fairly warm to rainy and cool. When I turned the rock over, the young racer was too cool to dart off. Oh, the disadvantages of being an ectotherm! Being cold-blooded means that if you hang out in a cold place, you are cold, too. The engines that drive all that nervous, alert activity depend on warmth, and if you’re a reptile you cannot generate your own heat. The little snake sat while I recorded it on video, tongue-flicking and moving slowly. It even flattened its neck vertically a little at one point, in a threatening display meant to make it look bigger. To see the video, click here.

In the summer, being an ectotherm would be a big advantage for the reptile. Us endotherms have to take in lots of nutrients so that our metabolic engines can constantly generate heat. Snakes are “solar-powered,” directly or indirectly, making use of sunlight or a sun-warmed environment to get up to speed. As a result, they do not have to eat as often. But on this day, at the end of winter, the little racer was slow-moving and vulnerable. After I got all the photos I wanted, I let her return to the shelter of the rock and wait for a warmer day.

If you find one, admire whatever glimpse you get of this snake and let it go. That three-feet or so of nimble hyperactivity will just make you sprain your ankle or get a face full of cactus if you chase it. Or maybe, if you’re lucky, you will find one under sheets of tin, or boards, or under a rock on a cool day when light speed is not an option. They are beautiful, graceful animals!

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