Western (Texas) Ratsnake

fullsizeoutput_1011Many years ago I was contacted to go to my son’s day care, which had some land and kept a few animals around a small barn. They said that a big snake had been eating the duck eggs, and the culprit had been spotted earlier in the day. I went over and had a look, and as I raked hay away from what appeared to be an old burrow in the floor of a stall, I caught sight of the dark coils of a ratsnake. After pulling about five feet of Texas ratsnake from her refuge, I then had to get a very unruly snake into the bag so that I could relocate her. A day or two later I took the snake to the wooded corridor of a large creek and tried to pose her for some photos before letting her go. This did not go particularly well; draping a big ratsnake along a log by the woods gives the snake an immediate plan for escape and a very impatient attitude about sticking around for pictures. Of course she turned and bit me. I stood, finger dripping blood into the creek, wondering how many hundred times I have been bitten by Texas ratsnakes. Meanwhile I did get a photo or two before the big snake climbed into the highest branches of a nearby pecan tree.

I wished her luck, and she would need it. Relocated snakes often do not do very well, because they learn to recognize a particular area (their “home range”) where they live, and when taken somewhere new, even if the habitat is pretty good, they may act as though they are lost, and wander without settling down. Many studies of translocated snakes show that they’re more likely to die, failing to avoid hazards and/or to take advantage of resources in the new location. However, sometimes a snake like this Texas ratsnake faces a dilemma: stay and be killed or get relocated and “lost.” At least in her new woodland, she had a chance.

While I stubbornly hang onto the name “Texas ratsnake,” this species was re-named a few years ago after improvements in the scientific understanding of the relationships among North American ratsnakes. Its proper name is now the western ratsnake, Pantherophis obsoletus. What used to be called the “black ratsnake” and “yellow ratsnake,” east of the Allegheny Mountains, is now the “eastern ratsnake,” Pantherophis alleghaniensis. In the middle part of eastern North America, they are Pantherophis spiloides, a new name for the gray ratsnake. West of the Mississippi River, they become western ratsnakes, but some habits are hard to break, and so I still call them Texas ratsnakes.

This species may be the subject of more run-ins with people than any other snake in our area. Lots of “snake calls” are generated by people seeing a Texas ratsnake in their trees or yards. Soon after eggs hatch at the end of summer, babies sometimes turn up in people’s garages and sheds. Lots of them are killed on the road each year. Yet somehow, they continue to be abundant year after year around parks and suburbs (as well as in more remote locations).

This is one of our longest snakes, averaging about 3.5 to 6 feet long, with a record length of seven feet, according to Werler & Dixon’s Texas Snakes: Identification, Distribution, and Natural History. Like several other ratsnake species, the Texas ratsnake’s body, seen in cross-section, is rounded on top and squared at the bottom, like a section of a loaf of bread. This is thought to aid them in climbing trees.

The adult snake’s fairly broad, flat head is dark gray on top, shading to white on the lips and chin. Starting with the neck, there is a pattern of dark saddles going down the back. The dorsal ground color may be yellowish-gray to gray or charcoal. Along the sides is another row of blotches, these being somewhat diamond-shaped. The skin between the scales of the neck and forebody generally includes reddish or orange color, more visible when the skin is stretched. Some of the skin between the scales within the blotches is light gray to white, showing as small flecks of white in a patch on the lower parts of the blotch. Add to this one further complexity of pattern – many adults have the suggestion of vague, smudgy stripes where the edges of the blotches seem to smear a little and join each other down the back. On the belly, the scales are light on the throat, darkening from front to back with large pale squarish blotches and then a mottling of gray and yellow toward the tail.

Texas rat snake - subadult female

A young adult Texas ratsnake with more yellow in the background color

E-o-lindheimeri-2_2

An individual with lots of gray color, though considerable red can be seen between the scales

Hatchling Texas ratsnakes have brighter and bolder patterns than the adults, with a light ground color so that the blotches stand out more. On the top of the head, juveniles have some dark spots and flecks, and a broad, dark band across the snout just in front of the eyes. That band then goes through the eyes diagonally to the jawline. The pattern darkens with age.

E-o-lindh- juv-LBJG-Jun02

Juvenile Texas ratsnake

Texas ratsnakes take advantage of a wide variety of habitats within roughly the eastern two-thirds of Texas where they are found. They occur in east Texas and down the Gulf Coast to Corpus Christi, and in central Texas to a little west of Wichita Falls, out to San Angelo, and southwest nearly to Del Rio. This means that they live in east Texas piney woods, bottomland hardwoods, cross timbers woodland, and savannas from north Texas down through the Hill Country. They are excellent climbers, and this may be one factor in their success, keeping them away from ground-based predators and people at least some of the time. While up in the trees, they may eat birds and their eggs.

My field notes and my memory indicate that I’ve found lots of Texas ratsnakes in patches of prairie, old fields with at least a creek nearby, and woodlands and forests. During the day, I have been more likely to find them by flipping cover such as discarded plywood or logs. I’ve seen a great many on back roads at twilight or at night, quite often in brushy or wooded areas, or within a short distance of a creek. Undoubtedly they use wooded creek and river corridors to move around in more dry, open areas further west in their range.

Both the accepted common name, “rat” snake, and the often used name “chicken” snake refer to some of their preferred food. A stomach contents study cited in Werler & Dixon, looking at 100 wild specimens in north Louisiana, found mice, rats, and a few squirrels and rabbits in their stomachs. This snake is more than happy to eat birds and their eggs. Coming upon nests, it may eat eggs or fledglings. A big adult reportedly can swallow an adult chicken. While this may not make the Texas ratsnake popular with either farmers or birders, it is simply doing its “job” and may eat enough rats that it does the farmer more good than harm.

The most memorable activity seen in Texas ratsnakes may be their belligerent self-defense when cornered or handled. When first approached, the snake may “make a break for it” or may stay where it is. I have often seen one pull its body into a series of short kinks and sit still, hoping that it won’t be seen. Once picked up, the snake thrashes in an attempt to get away, and may bite repeatedly while discharging musk from the other end. While some snake musk is only moderately disagreeable, musk from a Texas ratsnake is very offensive, a little reminiscent of burnt tires. But the open-mouthed gape while looking for an opportunity to bite is worse. Very commonly, having picked up one of these snakes, it remains coiled on one of your arms as if it were a tree limb while gaping at your hand or other arm as the obvious visible target. If your hand moves closer, the snake will strike, leaving a series of pinprick holes. Occasionally it will hold on and chew. It is important to remember that this only happens to humans who harass and pick up a ratsnake; an observer who simply watches and photographs will not be attacked.

TX-rat-gape-a

The famous Texas ratsnake gape, ready to bite the attacker

One additional note in defense of the Texas ratsnake, showing that biting is only self-protective and never because it wants to pick a fight: I have many times been able to pick up a Texas ratsnake by slipping a hand under it and supporting it while giving it no target that looks like an enemy. A freshly-caught ratsnake may crawl from one arm to the other as long as nothing comes at it like an attacker. However, this is in no way foolproof, and fairly often it pauses and seems to recognize that this is no tree, abruptly biting my arm. And again I would stress that I have never, ever been bitten by a Texas rat snake that I was  not handling or attempting to handle. They have no venom and they have no interest in becoming aggressive as long as they are left alone.

Spring mating results in the laying of a clutch of five to twenty eggs in June or July. The eggs are laid in rotting logs, in a protected area under leaf litter, in abandoned mammal burrows, or under rocks. It is also known to use above-ground tree cavities for nesting, and the description in Werler & Dixon notes that the tree cavity was used by perhaps four different females for communal nesting. The eggs hatch in August and September, and the baby snakes have much the same temperament as their parents!

(This article is adapted from one I wrote for the January, 2003 issue of the Cross Timbers Herpetologist, newsletter of the DFW Herpetological Society.)

Return to the Rolling Plains 

Storm clouds emblazon a Stonewall County sunset, as seen through the car window photo: Zev King

A flash of lightning illuminated the sky outside the passenger window, behind which a sun the hue of an overripe peach quickly slipped over the plains to the west. Deep puddles lined the roadway from bands of storms that were unleashing their late summer fury upon the thirsty red soil. A lone coyote, looking scraggly and thin, stood in the roadside grass, saw us approaching, and trotted across the two-lane blacktop and into a nearby cotton field, picking up pace even as he looked back over his shoulder with his tongue lolling sideways. From the seat behind me my son watched him disappear at its edge into a thick grove of honey mesquites. 

We were in Stonewall County in the middle of the Big Empty, with nothing but miles of shortgrass prairie, mesquite savannah, and low outcrops of red rock. Mark Pyle, my longtime friend and field accomplice, was manning the wheel, with me and my crutches riding shotgun and Zev in the back. I had only recently gotten out of one of my boot casts, and was eager to get out in the thick of it, crutches be damned.  And here was no better place and time. As dusk gave way to the black of night great horned owls winged in from out of the darkness and perched along the telephone poles at roadside like harbingers of rodent and rabbit death. The myopic refraction of whitetail deer eyes gave away their presence just outside the realm of our headlights, and once we had to swerve a band of feral hogs that came parading across the asphalt, seemingly out of nowhere. The lead boar looked as if it could have nearly doubled me in weight, and I frowned at the thought of these unscrupulous ungulate lawnmowers razing the rocky hardpan of plants and animals alike. In the sky above a nightjar boomeranged above the car, trying to hone in on the moths drawn to our headlights.  As the sun died the plains came to life. 


At the Haskell County line we set up a blacklight at a familiar roadside rest stop where a row of honey mesquites draped their thorny branches over the fenceline. We would check the light at the end of the night to see what was hopping on the invertebrate scene. Late August is a great time for blacklighting. Sphinx and giant silk moths are emerging in their final brood of the year, the fall blister beetle species begin to show up, and mantids and walking sticks begin to make their annual appearance. 

We drove back and forth along the mostly deserted highway for the better part of three hours, where we tallied up a sum of young-of-the-year rattlesnakes, all of them western diamondbacks. The largest of these was around two feet in length, and the rest were only months old, all of them perfect replicas of the adults, with their telltale diamond patterns etched in light colored scales and their black and white ringed tails bearing only the baby button and a single attached segment. In true western diamondback fashion they displayed a variety of temperaments, with some lying motionless and others instantly wriggling away.  On a good diamondback night there is always one ornery individual, and ours took cute little snaps at Mark’s hook as he scooted it to the safety of the roadside grass. 


Western diamondbacks may reach their greatest abundance in the state in this ecoregion. I have herped all over Texas and nowhere have I seen population densities so great as that area between Lubbock and Throckmorton. On a three day herpathon in mid-May of 2013 I racked up over a hundred snakes, 65 % of which had been diamondbacks. But it was 100 % on this night, and after 11:00, with the thermometer reading 71 degrees and due to drop into the low sixties by the morning, we decided to pull in the blacklight and call it quits. 

The rolling plains may no longer be a home where the buffalo roam, but it serves as the eastern boundary to a species of ant lion (Vella farfax) that is the largest in the United States.  Antlions are better known in their larval forms as ‘doodlebugs’, and are recognized by the familiar inverted cone shaped pitfall they use to trap ants.  The adult somewhat resembles a damselfly, although with a wingspan of up to 120 mm the giant species rivals that of our largest dragonflies.  These were in abundance around the headlight beams, and Zev hoped we would draw some to the blacklight, but they were strangely absent when we got there. We did, however, find a plethora of other insects. As predicted, several male mantids and a walkingstick were hanging out on the sheet, alongside several tiger beetles (Cicindela sp) and blister beetles  (Pyrota concinna) who looked pre-dressed for Halloween in their vibrant orange and black warning colors that advertised their witch’s brew of cantharadin.  A pair of mesquite girdlers (Oncideres cingulata) ambled across the sheet with their long antennae trailing along behind their elytra.  Several feet away a checkered beetle (Enoclerus quadrisignatus) waited for one of them to deposit its eggs so it could parasitize them with its own voracious larvae. 

A mantis snacks on a moth under the glow of the uv lights


The baby diamondbacks were still running strong as we made our way to the tiny town of Aspermont a little after midnight. There are only two motels there to choose from, but the one with the grey fox dining on crickets beneath the security light seemed appropriate, so we pulled in to get a little rest. It wasn’t the ritz, but with my leg throbbing and aching as I pulled it out of the accursed boot and into the bed, it beat a kicked back car seat or a sleeping bag under a mesquite tree by a long shot. 

Another mantis outside the Hickman Motel, Aspermont Texas


We awoke to a cool calm morning in the mid-sixties, and after an Allsups breakfast of granola bars and iced coffee (Mark had milk as he insists he’ll never stoop to drinking burned beans as I’ll never stoop to drinking from the mammary glands of another species…our lines are drawn) we broke once again for the wide open plains. 

Part of the reason behind our mini-trip ( at least the part we used to explain to our wives involving its absolute necessity) was to photograph a coiled western diamondback for the cover shot of the book Michael and I were still in the process of publishing, and Mark had brought along a robust, photogenic four-footer for just such purpose.  The goal was to get a good shot of the highway fading away to a central focal point on the horizon line, with the snake buzzing in the classic position in the foreground. We wanted to get this done in the cool of the morning if possible, and after a brief hunt for the “perfect spot” we did a short photo shoot just north of the town of Jermyn in nearby Kent County. It took about 20 minutes, and during that  period the sun came out and the temp began to climb. This brought the day crew out. The previous night’s owl posts were relieved of duty by redtail hawks; bobwhite quail bobbed along in their curious, synchronized huddles, and a trio of roadrunners peered at the car from beneath a mesquite as we passed by, their concentration only momentarily broken from the morning’s lizard hunt. 

Mark photos the atrox while I stand by and try to keep the shadow of my crutches out of the shot


We hadn’t gone far when we saw the high domed carapace of an ornate box turtle as it ambled along the pavement. While these brightly colored chelonians are sadly becoming an increasing rarity around the western cross timbers, they are still faring pretty well in undisturbed parts of the rolling plains. We pulled over to photograph this one, and Mark got a little too close and received a good nip from the little turtle’s strong beak.  It was hard enough to draw a small amount of blood, as well as a large amount of teasing from Zev and I. Apparently these rolling plains box turtles didn’t owe their survival out here to meek dispositions and blackberries! It was flesh and true grit that would see them through another day!

The Terrapene Terror poses calmly for a picture just minutes before the incident, looking the picture of innocence.


By now the sun had warmed the air to over 80 degrees, and while we weren’t surprised to see a western coachwhip come streaking across the road, we were by the only other live snake we saw that morning: a juvenile eastern hognose.  Eastern hognose snakes can be quite common in parts of their range (in spite of Michael Smith’s apparent lifelong jinx when it comes to finding them) but are not so in the rolling plains, where they are replaced by the smaller, more boldly patterned western hognose. In fact, in nearly 20 years of herping the area this was only the third specimen I had come across.  We were thrilled to find this little guy out and about, and it ended up being a county record. After a series of photos Mark carried the pintsize bluffer to the fenceline and released it into the grass. 



Several minutes later we pulled over for a much more commonly seen denizen of the plains. This was a Texas horned lizard, and it sat calmly along the white line as we gathered around it for photos. Not even the squeaking, mechanical approach of the bionic crutch-herper frightened it. Texas horned lizards, even moreso than box turtles, have disappeared from much of their former range, but are still found in healthy numbers in much of the rolling plains. This is likely due to the arid climate that supports dense populations of the red harvester ants that constitute the bulk of the lizards’ diet, while preventing invasions of the moisture-dependent imported red fire ant that threatens both the lizard and harvester ants.   After photographing it, Mark made sure the horned lizard made it off the road safely by toeing it into the grass. As a result he ended up getting a harvester ant sting on his leg. Apparently the rolling plains was giving Mark a run for his money. 


Dozens of diamondbacks, bitey box turtles, horned lizards and hognose…I could think of no better way to ring in my return to the field!

Hanging Out With Master Naturalists

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.

fullsizeoutput_fec

A green treefrog at the boardwalk, FW Nature Center & Refuge

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.

IMG_2226

American bullfrog (photo taken at LBJ Grasslands, Wise Co.)

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.

fullsizeoutput_ffb

Bottomlands, Fort Worth Nature Center & Refuge

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.

img_1280.jpg

Little brown skink

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.

IMG_2337

Spiny orb weaver

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.

IMG_1283

Bess beetle

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.