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Texas Snake Markings
& Coloration by Jerry Cates Note: The photos shown on this page were mostly provided by viewers who, in return for assistance in identifying the snake granted us exclusive use. We, in turn, permit the lawful use of these photos by others, with the strictly enforced proviso that attribution and a link to www.bugsinthenews.com be provided with each use.
Does the above pattern say anything to you? If you see a snake with these markings on a trail, will you know to give it a wide berth? Using the material that follows you will learn to tentatively identify snakes by their markings and coloration; numerous photos, like the above, are included for that purpose. Basic Guide To Texas Snake Markings & Patterns Several basic patterns are officially recognized by herpetologists who study and write about Texas snakes, but--strangely--the nomenclature is not precisely defined. Besides the small number of official descriptors, many other expressions are used by herpetologists in an unofficial, almost off-hand way, to characterize the snakes they write about. I have attempted to include the wider range of descriptors in the list below. Keep in mind that this evolving work will change over time: 1. Unicolor, Unmarked, or Unpatterned: A single color to the scales, and usually the interstitial spaces between the scales, over the spine and sides of the snake, without any obvious markings; many unpatterned snakes have a single color to the scales and belly, or a paler or slightly different coloration to the interstitial spaces between the scales, and to the belly as well. Many of our smallest snakes are unmarked; if you see a small, unmarked brown or gray snake, with a small head, in your garden, it is likely to be one of our harmless, small garden snakes. An all-black small snake with a small head, however, may be a venomous, melanistic, Texas coral snake. Large, darkly colored, unmarked snakes are difficult to identify. Many species, both venomous and harmless, tend to darken with age and lose the patterns of their youth. If you meet such a snake, in your garden or on the trail, you will need to observe its head and tail to identify its species. 2. Spinal Blotch, Saddle, or Diamond: Relatively large square, rectangular, diamond-shaped, oval, or saddle-shaped markings, occupying more than eight dorsal scales [an important distinction made by Werler & Dixon, in their book, Texas Snakes], running in a single row down the snake's spine. The word "Diamond" is, by convention, used almost exclusively for the sometimes indistinct, often un-diamond-like markings along the spines of (in Texas) western diamond-backed rattlesnakes (Crotalus atrox), and (further east) eastern diamond-backed rattlesnakes (Crotalus adamanteus). The photo at the head of this article is of the spinal markings of a western diamond-backed rattlesnake. Many other snakes, both venomous and harmless, have diamond-like markings along their spines. Most of the harmless rat snakes, for example, have dark, sharply defined, spinal blotches or saddles that resemble diamonds. However, once you become familiar with the markings of a diamond-backed rattlesnake, you won't likely mistake them for those found on our harmless Texas snakes. 3. Lateral Blotch: Relatively large square, rectangular, diamond-shaped, or oval markings, occupying more than eight dorsal scales, running in one or several rows longitudinally along the snake's side ("saddle-shaped markings" are only descriptive of markings that occur along the spine of the snake, for obvious reasons, even though similarly shaped marks may be found along the snake's sides). Large markings on the sides of a snake are as useful as indicators of the snake's identity as those along the snake's spine. For many harmless snakes, such as the Texas rat, the bull snake, the Texas glossy snake, and the checkered garter snake, lateral blotches may be the first thing you notice. 4. Spot, or Speck: Not as large as a blotch, i.e., one that occupies less than eight dorsal scales, but that may occupy as few as a single dorsal scale and, in fact, may not fully occupy the scale it is confined to. 5. Band, or Ring: A band or ring of coloration that completely encircles the snake's body. The fact that a band or ring of coloration fully encircles a snake's body isn't immediately clear when you encounter the snake in the wild. It helps to become familiar with the markings of our snakes before you encounter them. 6. Crossband, Half-Ring, or Bar: A band or ring of coloration that passes laterally across the snake's spine onto the snake's sides, without fully crossing the snake's belly. Some crossbands, half-rings, and bars on the back and sides certain snake species clearly terminate before they reach the lower region of the snake's side. Others extend all the way to the belly, and some even encroach on the belly, before they are interrupted. 7. Spinal Stripe: A longitudinally-oriented stripe or strip of coloration along the snake's spine, often extending from the head to the tail. 8. Lateral Stripe: A longitudinally-oriented stripe or strip of coloration along the snake's side, often extending from the head to the tail. Some snake species have several such stripes along their sides. Examples:
Above photo: Unicolor, Unmarked, or Unpatterned: western smooth earth snake (Virginia valeriae elegans) adult, midbody. Harmless
Above photo: Unicolor, Unmarked, or Unpatterned: rough green snake (Opheodrys aestivus) adult, midbody. Texas has no unmarked blue snakes, but you may find a dead snake that is unmarked and blue; if you do, it is almost certainly one of our two unmarked green snakes; both turn blue at death. Only two species of green snakes are found in Texas; this one, and the the rare western smooth green snake that forms a relict population along the Gulf Coast; both are Harmless
Above photo: Band or Ring: Texas coral snake (Micrurus fulvius tener) adult, midbody; the black, yellow, and red bands of this species extend around the body, including the undertail scales: "Red touch yellow, kill a fellow; red touch black, friend of Jack." Venomous
Above photo: Band or Ring: Western diamond-backed rattlesnake (Crotalus atrox) adult, tail (note the rattles); the black bands on the tail of this species extend around the body, including the undertail scales, though they become a slightly paler shade of dark gray at the belly (a shade that continues to contrast sharply with the stark whiteness of the adjacent white bands). Venomous
Above photo: Crossband, Half-Ring, or Bar: Broad-banded water snake (Nerodia fasciata confluens) adult, midbody. Photo courtesy of Scott Copeland, Quinlan, Texas. Harmless
Above photo: Crossband, Half-Ring, or Bar: Eastern hog-nosed snake (Heterodon platirhinos) adult, midbody. Harmless
Above photo: Crossband, Half-Ring, or Bar: western coachwhip snake (Masticophis flagellum testaceus) adult, midbody. Note that this specimen, on this portion of the body, is unpatterned within each broad crossband (the crossbands are not starkly conspicuous, but two dark crossbands are visible in the photo, preceded at both extremities by portions of a lighter crossband, with one lighter crossband in midphoto), but its scales contrast with the interstitial spaces between them. It is more common for western coachwhips to exhibit narrow crossbands in the forward third of the body and to be otherwise unpatterned throughout the remainder of the body. Harmless
Above photo: Jagged-edged crossbands: timber [in Texas, more properly known as the canebrake subspecies, which prefers thick riparian brambles to open woodland] rattlesnake (Crotalus horridus) adult, midbody. Venomous
Above photo: Bold, Narrow Crossbands: Great Plains ground snake (Sonora semiannulata semiannulata) adult, hindbody (the same pattern is exhibited in the fore and midbody regions). Harmless
Above photo: Ill-defined crossbands: western cottonmouth (Agkistrodon piscivorus leucostoma) adult, midbody. Note the similarity with the hourglass pattern on the southern copperhead, a member of the same genus as the western cottonmouth (shown elsewhere on this page). Photo courtesy of Scott Copeland, Quinlan, Texas. Venomous
Above photo: Blotch, Saddle, or Diamond: Texas rat snake (Elaphe obsoleta lindheimeri) adult, midbody. Harmless
Above photo: Blotch, Saddle, or Diamond: prairie kingsnake (Lampropeltis calligaster calligaster) adult, midbody. The prairie kingsnake has 50 or more irregular spinal saddles, and its sides are marked with even more jagged spots; the serpent darkens with age. Harmless
Above photo: Blotch, Saddle, or Diamond: Sonoran gopher snake (Pituophis catenifer affinis) adult, midbody. The Sonoran gopher snake is similar, at midbody, to the prairie kingsnake, the bull snake, the Texas night snake, the Texas glossy snake, and the Great Plains rat snake. It is distinguished from these by the fact that its blotches reduce to half-rings at the tail (a feature that it shares with the bull snake) and that its blotches darken noticeably from midbody to the tail, where they are almost black (a feature the bull snake does not have). Harmless
Above photo: Spinal Blotch, Saddle, or Diamond: blotched water snake (Nerodia erythrogaster transversa) adult, midbody. Photo courtesy of Scott Copeland, Quinlan, Texas. Harmless
Above photo: Blotch, Saddle, or Diamond: eastern hog-nosed snake (Heterodon platirhinos) adult, midbody. Note that this species exhibits considerable variation from one specimen to the other. Many other snake species are similarly variable in coloration and marking. Harmless
Above photo: Alternating light and dark half-rings: eastern hog-nosed snake (Heterodon platirhinos) adult, tail. Note that the rings are paler toward the bottom, where the lateral scales approach the belly; they fade completely at the belly. Harmless
Above photo: Diamonds: Western Diamond-Backed Rattlesnake (Crotalus atrox) adult, mid-body. Venomous
Above photo: Diamonds: Western Diamond-Backed Rattlesnake (Crotalus atrox) adult, mid-body. Photo courtesy of Scott Copeland, Quinlan, Texas. Venomous
Above photo: Hourglass: Southern copperhead (Agkistrodon contortrix contortrix) adult, midbody. The hourglass marking is a kind of crossband or half-ring, but in many southern copperhead specimens the portion of the crossband on one side of the snake stops abruptly at the spine, without crossing over to the other side. Venomous
Above photo: Spot, or Speckle: desert king snake (Lampropeltis getula splendida) adult, midbody. Photo courtesy of Scott Copeland, Quinlan, Texas. Harmless
Above photo: Spot, or Speckle: buttermilk racer (Coluber constrictor anthicus) adult, midbody. This curious marking consists of an olive, steel-blue, aqua, slate, or brown background color speckled randomly with white, tan, yellow, or gray scales; each scale is, in general, a single color. Only this species exhibits this unique marking. Harmless
Above photo: Spinal and lateral stripes, with square spots: checkered garter snake (Thamnophis marcianus marcianus) adult, midbody. Note that the bright yellow spinal stripe is unusually thin, covering less than the width of a single scale; it is bordered on either side by a double row of square or rectangular black spots that are distinctly separate from one another to produce a checkerboard pattern. Harmless
Above photo: Stripes and spots: eastern black-necked garter snake (Thamnophis cyrtopsis ocellatus) adult, midbody. Note that the bright red-orange spinal stripe is bordered by a double row of black spots that merge with one another to produce what appears at first to be a broken set of vertical white marks. If you squint your eyes to blur the image you will immediately see the rows of black spots on a white background; these are much more obvious in the juvenile. Harmless
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