Snakes whose length is less than five times the width of the road’s yellow line are considered small snakes.
Garter Snakes (Thamnophis species)
12–18 inches
This may be the only snake you can identify on the road at highway speeds. All garter snakes have one or more clear, light-colored longitudinal stripes running the length of their bodies (they may appear as spirals in the older road forms). The stripes are usually visible for several days. Some species of garter snakes occur everywhere in the U.S. They are likely to be the second most common road snake (see “Large Snakes”).
Green Snakes (Opheodrys species)
12–14 inches
Green snakes are sufficiently striking in color to be recognizable for nearly a day. Most are a uniform jade green color above, and white to yellow below. They are found everywhere except the mountain states and Pacific coast.
Ring-necked Snakes (Diadophis punctatus)
12–18 inches
These are small, almost totally nocturnal snakes. They are slate gray to black in color, with a yellowish to orange ring around the slender neck, and an orange to red underside at the tail end. The ring is not generally visible at any speed above 25 mph, but the undertail color can be seen at higher speeds. Both eastern and western forms occur, differing only slightly in the color and width of the neck ring and underside color patch.
LARGE SNAKES
Any snake extended a quarter or more of the width of a standard traffic lane is considered a large snake.
Bull Snakes (Pituophis melanoleucus)
5–8 feet
The bull snake can be found all over the U.S. and all over many highways. It is easily the most abundant snake on the road. H. Elliot McClure identified 398 bull snakes out of a total highway mortality list of 6,723 birds, mammals, and reptiles. Only toads were more common on McClure’s list. The body is uniformly tapered and on the slim side for a temperate zone snake.
Garter Snakes (Thamnophis species)
3–4 feet
Most of the garter snakes on the road are young and inexperienced, but now and then a larger, older snake is caught napping.
Hognosed Snakes (Heterodon species)
The hognosed snakes are not common on the road, but may be recognized when seen. Along with rattlesnakes (see below), they are the most abundant thick-bodied snakes likely to be found from the Atlantic seaboard to the Rocky Mountains. Two characteristics deserve special mention. The hognose is the only snake that eats toads, and during a time of large-scale toad movement, it may be found with the toads on the roads. This snake will also “play possum” (see “opossum”) and, if harassed by a near miss, will curl up and give a most convincing demonstration of lifelessness—a demonstration that almost inevitably turns into the real thing.
Rattlesnakes (Crotalus species)
3–8 feet
Rattlesnakes are unusual road residents except for in the southern Appalachians and the Southeast generally, where they are still abundant enough to equal the number of most other road-snake species. They are thick-bodied like the hognose and, when silent (as most are), are indistinguishable from them on the road.
Water Snakes (Nerodia species)
3–5 feet
Water snakes are aggressive and will not usually back down from a confrontation with anything. Their vigorous striking will often keep smaller predators at bay, but automobiles are notoriously unresponsive to their threats. Water snakes are dark, not dramatically marked, and about average in overall shape. Only the nearness of a pond or river will help suggest that the dark, tapered shape on the road might once have been an aggressive water snake.
chapter 4
This is a composite category mostly because of processes that occur on the road. The pebbled surface of a flat toad cannot be distinguished from the scaled surface of a flat lizard or turtle at even the slowest observation speeds, and the thin-skinned frogs disappear from the road so quickly that they are not even included in the guide. If the road animal has (or appears to have had) four legs and lacks any evidence of fur, it probably belongs in this section. (Very old road mammals are often nearly bald except for a fringe of fur around the edges.) Reptiles and amphibians tend to appear hard-edged on the road. The only seriously problematic creature for most travelers is the southwestern armadillo. This is larger than all but the largest turtles you are likely to see on the road, and has a more elongated shape than any turtle (turtles do not generally elongate on the road). The armadillo’s longer snout alone is often sufficient to distinguish it from any turtle.
Toads are the most common road animal in the “Legged Reptiles and Amphibians” category, although in special circumstances turtles of particular species may be seasonally abundant. In McClure’s study of Nebraska roads, toads were seen nine times as often as frogs or salamanders and approximately eight times as often as the most common turtle. Only rarely will lizards comprise anything but a minor component of the flattened fauna. An outbreak of road lizards would be worth an immediate report to International Simmons Society headquarters.
The return of the American alligator (Alligator mississippiensis) to the highways of Florida must count as one of the greatest comebacks in the history of road fauna. Twenty years ago this creature was too rare to be worth mentioning. Its flattened return to its former habitat must be viewed with satisfaction.
ROAD TOADS
(Mostly genus Bufo)
HABITS AND ABUNDANCE In northern climates, spring is the toad’s breeding season, and large numbers of hormonehigh toads will be found on almost any road following early spring rains. Any toad wishing to be represented in the next generation must find a pool of shallow standing water and a consenting toad of the opposite sex. Apparently not all toads successfully make such a migration, considering the attendant highway hazards. The same large, easily identifiable toad has lived under our front porch for at least ten years; and unless it sneaks away to a pond under cover of darkness and returns quickly, it seems not to have felt the hormonal surge that would send it journeying across any adjacent streets. It remains safe but, I suspect, unfulfilled; it certainly won’t leave any offspring with the same stay-at-home tendencies. Southern toads breed at almost any time through the summer, and toad traffic may be heavy following almost any downpour. Among road fauna, toads are the only gregarious animals, and will often be found in large numbers within a few feet of one another.
Most natural predators avoid toads, as the toad’s skin contains glands that secrete distasteful milky substances. Feeling safe from harm in most circumstances, a toad’s natural response to impending danger is likely to be hunkering down rather than leaping away. This behavioral response produces a more uniform road pattern for toads than for any other creature in this guide. Flat toads are so nearly square as to be almost geometrical in their road presentation. Hognosed snakes seem to prefer toads, secretions and all, as food, and may be found in association with them on the road during toad migrations.
FIELD MARKS AND RANGE This common immobile amphibian is found in all parts of the country and in habitats ranging from plains to mountains to deserts. It is likely to be the first amphibian specimen the beginner will encounter. Visually similar but differently named species are found in various geographic regions. Species are normally distinguished on the basis of color and minute anatomical features, none of which survives flattening. However, the rough, almost beaded-looking surface characteristic of nearly all species is persistent and diagnostic, even after days on the road. Road toads are generally dark and uniform in color, about three inches by three inches, with one limb usually visible at each corner. Often a forelimb is extended as though the toad were waving goodbye.
American toad (Bufo americanus)
The toad’s tendency to flatten itself against the ground when threatened or afraid produces a uniform road pattern. The illustration is drawn from an actual specimen (male). Females are somewhat larger.
ROAD TURTLES
Turtles are hist
orically significant. They entered the road fauna earlier than any other group. Any turtle that tries to get across a road, even with very slow-moving and sporadic traffic, is likely to become a permanent part of the scene. If a highway bisects the route turtles traditionally take to lay their eggs on some sandy spot, the road may resemble the site of a recent accident involving the Acme Casserole Company truck. Only a few kinds of turtles are likely to be identified as members of a particular species. A list of identifiable road turtles follows.
Painted Turtles (Chrysemys picta)
8–10 inches maximum diameter
Much of the color on the painted turtle’s carapace, or shell (which gives this turtle its common name), does not survive the flattening process. Most specimens, however, will retain a bright red edge all around the shell. The shell itself is most often reduced to crumbled fragments, which look like a pile of dark crockery dropped from a considerable height. The painted turtle is found everywhere but in the Deep South.
Painted turtle (Chrysemys picta)
Turtles are, individually and as a group, so flat to start with that little dramatic shape change can be expected even after they have spent considerable time on the road. Slight variation in length of tail and extension of the head and neck will serve as aids in specific identification. Turtles begin and remain close to the road. The specimen shown is a male (identified by the large front claws). While this particular specimen is shown actual size, turtles of the same species can vary in size from about three inches to ten inches in length. Photocopy by Canon NP-350F.
Desert Tortoises or Gopher Tortoises (Gopherus agassizi)
12–14 inches maximum diameter
As the common name suggests, this turtle is restricted to the sandy areas of the Southwest. Most of these tortoises maintain separate feeding and hibernation areas and must travel from one to the other. New highways may cross the tortoises’ usual paths and provide the best places to look for this once-common but now protected species.
Snapping Turtles (Chelydra serpentina)
18 inches maximum diameter
Snappers are almost totally aquatic, and they will be found on the road only during the spring egg-laying season. Compared to other turtles, their shells seem much too small for them, nor can their large head and long tail be retracted. The head and tail of a snapper will always be apparent on the road. Snapping turtles may be found during spring and fall anywhere in the eastern two-thirds of the country.
Soft-shell Turtles (Trionyx species)
14–24 inches maximum diameter
This is the only turtle that bends rather than breaks under the battering of the passing parade. If you find a uniformly oval spot, dark in color and appropriate in size, with just the hint of a long pointed nose at one end, it is likely to be a soft shell, especially on roads near rivers. It is found everywhere but the Rocky Mountains and the desert Southwest.
ALLIGATORS
American Alligators
(Alligator mississippiensis)
1–4 feet long
This animal was once threatened with extinction, but it has made a dramatic comeback in recent decades. Now it is common enough to merit mention, even though its range is limited to Florida and the Gulf Coast.
HABITS AND ABUNDANCE The American alligator is nine inches long at hatching and leaves the nest while still young and near that size. The death rate for young animals is very high, as the highway attests. These alligators are never far from water, but where modern highways cut through swamps or near waterways, they cross roads as readily as they do any other bit of land. When small, they are potential food for many predators and so remain wary; but once they grow to about three feet (at about two years old), they begin to lose their fear and develop the aggressive behavior pattern that places so many animals on the road. By most standards, alligators are not smart, nor is any creature that approaches the road totally without fear.
FIELD MARKS AND RANGE The young alligator has vertical yellow stripes that are visible on the road for many days. Older animals lose the stripes and are uniformly dark, often resembling a large shoe or purse that someone has abandoned on the road, but with legs and a rough-edged tail. The alligator is found only in Florida and the Gulf states, with the exception of the occasional escaped or released pet in northern cities. An alligator seen on the streets of Boston or New York should immediately be reported to the International Simmons Society.
American alligator (Alligator mississippiensis)
No size indication is given with this silhouette, since the road alligator may be anywhere from a foot to four feet long and show exactly the same shape. Although the curve of the tail is not characteristic, it is often found in heavy traffic where a second car closely follows the first. The tail ridges shown here are characteristic and should be visible at highway speed.
chapter 5
The irregularly shaped splashes of color provided by birds set them apart as the most varied group of road fauna. Numerous studies have revealed that more species of birds end up on the road than any other single category of flattened fauna. Their numbers are not likely to be large in any one locality. However, two or three rare, documented, seasonally gregarious species—pine siskins (Spinus pinus) and both red- and white-winged crossbills (Loxia curvirostra and Loxia leucoptera)—have been reliably reported in large dead flocks on British Columbia roads in winter. More commonly, you will see single birds of various species. It is not unusual to encounter a dozen different species in a short late-summer outing on a good road. (See Introduction.)
Birds are the only part of the road fauna that show much of their original color in all conditions and ages on the road. They are distinguishable at a greater distance than most mammals and can be identified with no slowdown or delay. Subtleties of pattern will be lost as the flattening process proceeds (eye rings are seldom visible, for example), but major color patterns are retained for a long time with almost no loss of brilliance. A flat oriole provides a color contrast that is most welcome and distinctive on the generally drab highway surface. A bird cannot hide on the highway as it can in a forest or field. Our avian heritage is most observable in the flattened bird fauna, and birdwatching on the road is a fine way to begin understanding our feathered friends.
The birds listed in this section are in two major categories—urban birds and rural birds—paralleling the driving habits of most observers. You are most likely to encounter urban birds near cities or towns. Any overbuilt, human-inhabited area qualifies as urban; birds do not understand city speed limit signs. Within each major category the birds are listed by size, from smallest to largest.
Belted kingfisher (Megaceryle alcyon)
Rarely, a bird will be captured on the road resembling its appearance in flight, apparently arrested in a split second of time. The arrested bird shown here is a belted kingfisher (Megaceryle alcyon), not otherwise described in the guide because of its rarity on the road. It is presented at the beginning of the bird section as an example of the sort of ideal specimen of any bird that readers might search for. Photocopy by Canon NP-350F.
URBAN BIRDS
House Sparrows (Passer domesticus)
5-inch body, 7-inch wings
HISTORY, HABITS, AND ABUNDANCE This import from Europe, which probably originated in Africa, is included among the urban birds mostly because of its history. It has lived with and near human dwellings for so long that its geographic origin is uncertain. From the earliest times, migrations of people have been accompanied by sparrows—especially once goats, cows, sheep, and horses were domesticated and dung became abundant near human dwellings. In the early 1850s a few sparrows were brought to the U.S. and released in several locations. By the 1870s every eastern city had huge flocks. The sparrows commonly fed in the streets, where undigested seeds in horse dung provided abundantly for their increasing numbers. Documentation is uncertain, but I believe the sparrow was the first bird to find its way into the road fauna. In 1862 in Philadelphia, on Chestnut Street, a lone male is
reported to have been mashed under the wide wheels of a passing delivery wagon. The event caused widespread amazement, and was reported briefly in the local press. There is now some question whether the bird died a natural death and was later flattened, or whether it was actually caught by the passing wagon. Only God knows for sure about sparrows.
As trucks have replaced wagons on the streets of major eastern cities and the supply of fresh horse dung has diminished, the house sparrow has taken to the countryside and is now less abundant in cities than it was in 1900. Even though fewer urban sparrows are present, their abundance in the road fauna has remained constant or even increased, due mostly to the dramatic increase in speed and numbers of vehicles.
FIELD MARKS AND RANGE Sparrows have always followed horses, and large flocks can now often be seen near human dwellings in rural or near rural settings. Roads near a riding or boarding stable are fine places to look for outstanding specimens of this road resident. The sparrow is easily the most common small bird in the entire road fauna. In 1938, Iowan Thomas Scott estimated that thirteen sparrows were plastered to each mile of highway there each year. The house sparrow is found throughout the U.S. and much of Canada, where it breeds during the entire year, except in the northernmost parts of its range.
On the road, prominent and dingy white patches of feathers will show for the first day or two, depending on the season (they last longer in winter). After than, most sparrows are pretty much road-colored, with few distinguishing features other than size and the lack of prominent color patches. Very few other sparrow species or birds of similar size are found on the road. If what you see is mostly gray or tan with some faint stripes and a bit of off-color white, and about six inches in maximum diameter, it most likely is (or was) a house sparrow.
Flattened Fauna, Revised Page 4
