Key_to_local _amphibians_ and_reptiles by pengtt

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									Key to Amphibians and Reptiles of the Ames Area 1A Skin smooth or warty and lacking scales; larvae and adults morphologically distinct; larvae are tadpoles, or have external gills with or without legs; adults are terrestrial or semiaquatic; larvae are aquatic (class Amphibia) ….….………..…. 2 Scaly skin; juveniles and adults occupy similar habitats and are morphologically similar except for body size and (sometimes) body color pattern; semiaquatic or terrestrial (class Reptilia) …………………………………….………..……..….19 Animal is a tadpole (robust head lacking external gills; legless with long tail for most of this life stage; legs emerge during metamorphosis, with hind legs emerging first), or has featherlike gills on head with legs present or absent (class Amphibia larvae) ………………………………………………………………....3 Animal has four legs and lacks gills; tail present or absent (class Amphibia adults) ……...………………………………………………………………………..…...11 Specimen has external, featherlike gills; legs absent or present; total length (tip of snout to tip of tail) to 24 cm (order Caudata) ………………………..…………….....…Ambystoma tigrinum (tiger salamander) Specimen lacks featherlike external gills (tadpole; order Anura) ……...........……4 Tadpole dorsum is uniformly dark-colored from head to tail (may appear black); eyes located on dorsal region of head; body somewhat flattened dorsoventrally; ventral margin of tail musculature usually lacking pigment; total length to 2.4 cm .….....……………………………………….….Bufo americanus (American toad) Body color not uniformly dark-colored for its entire length, although dark mottling or banding may be present; total length often greater than 2.4 cm ...…...5 Eyes located on lateral or dorsolateral region of head; tail tip sometimes dark; total length up to 4.4 cm………………………………………………….....…….6 Eyes located on dorsal region of head; tail tip never dark ………………….…….9 Eyes located on dorsolateral region of head; tip of tail usually dark-colored, but may be colorless; dark bands occur on dorsum of tail musculature; middle or anterior region of tail fin does not rise high above rest of body; intestinal coil visible through body wall; total length to 4.4 cm….. Acris crepitans (cricket frog) Eyes located on lateral region of head; tip of tail not dark colored; middle or anterior portion of tail fin often rises high above rest of body……………..……..7 Middle of tail fin high and often mottled with black; tail usually ends in distinct flagellum; tail often with red-orange tinge; body color variable; intestinal coil visible through body wall; total length to 3.8 cm …......………………………Hyla chrysoscelis or Hyla versicolor (gray treefrogs) Tail does not end in distinct flagellum; tail lacks red-orange tinge; total length might exceed 3 cm ….…………….……………….……..…………….…….…...8

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Tail fin colorless or weakly mottled; tail musculature usually bi-colored, with dorsal region being dark; dorsal body color brown, black, or gray; ventral body color bronze or silvery; intestinal coil visible through body wall; total length to 3.7 cm ...…….……………………………........Pseudacris triseriata (chorus frog) Tail fin pigmented or clear; pigmentation, if present, is concentrated along the outer edge of the tail fin; area near tail musculature is clear; total length to 3.4 cm……………………..…………....…...……Pseudacris crucifer (spring peeper) Intestinal coil at least partly visible through body wall; body color green or brown; tail fin mottled with flecks (but not well-defined spots); total length to 8.5 cm………….…………………………..……Rana pipiens (northern leopard frog) Intestinal coil not visible through intestinal wall (except in some very small individuals); dark-colored dashes, splotches or well-defined spots occur on body and tail fin; total length up to 16.2 cm ……………..……………………...…….10 Dorsum of body and tail fin of large specimens greenish with well-defined black spots; total length to 16.2 cm……………..….………Rana catesbeiana (bullfrog) Body greenish and mottled with fuzzy dots, dashes, or splotches (but not distinct round dots); total length to 10.0 cm….………...…....Rana clamitans (green frog) Tail present; costal grooves on lateral region of body; yellow spots or blotches usually on dorsum; total length (tip of snout to tip of tail) to 21 cm; (order Caudata, family Ambystomatidae)..….…Ambystoma tigrinum (tiger salamander) Tail and costal grooves absent (order Anura) …………………...…………..…..12 Paratoid glands present; one or two warts in each spot on dorsum of body; body length (excluding legs) to 9 cm; call is a long trill (Bufonidae) …………………………………………..…......Bufo americanus (American toad) Paratoid glands absent……………………………………………………………13 Suction cups on toes; can stick to vertical surfaces; body length to 5.1 cm (Hylidae)…………………………………………………………………………14 No suction cups on toes; body length to 15.2 cm (Ranidae)…….……………....17 Suction cups as wide as toes; skin smooth; striped pattern on dorsum (sometimes difficult to see in wet specimens); body length to 3.9 cm; call resembles sound of finger being rubbed along a comb …...Pseudacris triseriata (western chorus frog) Frog does not have above combination of features……………………………...15 Suction cups are wider than toes; skin smooth; an X-pattern occurs on the dorsum; body length to 3.2 cm; call a series of birdlike “peeps” ……………………………………………..…Pseudacris crucifer (spring peeper) Skin at least somewhat warty; X-pattern does not occur on dorsum; body length to 5.1 cm……………………………………………………………………….……16

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Suction cups are wider than toes; skin somewhat warty; coloration usually gray or green with mottling; usually has white spot under eye; concealed regions of hind legs orange or yellow with black mottling; body length to 5.1 cm; two species distinguishable only by voice; call a slow trill (H. versicolor) or faster trill (H. chrysocelis) ………….…....Hyla versicolor or Hyla chrysoscelis (gray treefrogs) Suction cups not wider than toes; Scattered warts on skin; dark green or brown triangle sometimes present on head; body length to 3.8 cm; call resembles sound of small stones clicking together in rapid succession …………………………………………………….…Acris crepitans (cricket frog) Dorsolateral ridge absent from trunk; dorsum plain green or with a netlike pattern of gray or brown on a green background; venter white to yellowish, and often with variable degrees of mottling; body length to 15.2 cm; call a vibrant series of bass notes often described as “jug-o-rum”…....……...Rana catesbeiana (bullfrog) Dorsolateral ridge present on trunk; large spots might be present on body and legs; body length to 9 cm...……….………………………………………..…….18 Large spots on body and legs (although spotless variants sometimes occur); body length to 9 cm; call a long, rattling snore interspersed with clucking grunts ……………………….……………………...Rana pipiens (northern leopard frog) Spots very small or absent; dorsum body color green to brown; venter white but usually some mottling or spots under head and legs; throat of male bright yellow; body length to 9 cm; call resembles the sound of a plucked banjo string ………..……………………………….…......…....…Rana clamitans (green frog) Body covered by large shell (a carapace and plastron joined by bony bridges) (order Testudines)…………...………………………….…………………......…20 Body not covered by shell; legs present or absent……………………….……....25 Shell soft, pancakelike, and lacking scales or scutes; long neck; snorkel-like snout …….….. ………….…………..……………………………………………...…..21 Hard shell with scales, scutes, and/or prominent ridges ……….……….…….... 22 Anterior edge of carapace with spines; feet strongly streaked and spotted; surface of male’s carapace feels like sandpaper, but female’s carapace is smooth; large dark spots present on carapace; shell length to 42 cm …….……………..…………………...…Apalone spinifera (spiny softshell turtle) Anterior edge of carapace lacks spines; feet unpatterned; surface of carapace always feels smooth; carapace unpatterned or with flecks (not well-defined circular spots); shell length to 36 cm ...…Apalone mutica (smooth softshell turtle)

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Dorsum of carapace saw-toothed; posterior region of carapace serrated (keeled; most prominent in young individuals); head large; tail long (almost as long as carapace); plastron small; body color brownish to black; shell length to 36 cm …...…………………….…………Chelydra serpentina (common snapping turtle) Dorsum of carapce not saw-toothed; carapace unkeeled; tail much shorter than length of carapace; dorsum of tail not saw- toothed………………..…...……….23 Broad reddish (rarely yellow) blotch behind eye; yellow to green stripes on head, neck, and each scute of shell; color pattern often obscured in older, dark (melanistic) specimens; shell length to 20 cm …………………………………….……..…..Trachemys scripta (red-eared slider) Color pattern present, but not as above………………….………...……………..24 Colorful pattern of yellow and red on body; yellow streaks on head; red and yellow might be present on carapace, plastron and/or tail; shell length to 18 cm ……………………..………….………………....Chrysemys picta (painted turtle) Light yellow spots, flecks, or streaks on carapace (may be absent in juveniles); chin and throat bright yellow; domelike carapace (absent in juveniles); shell length to 18 cm; juveniles have long tails ……………………………………….....Emydoidea blandingii (Blanding’s turtle) Four legs present; many dorsal stripes, with broad lateral stripe; dorsal scales smooth, shiny; total length (tip of snout to tip of tail) to 23 cm (order Squamata, suborder Lacertilia)………………………Eumeces septentrionalis (prairie skink) Legs absent (order Squamata, suborder Serpentes) ...…………………………...26 All body scales smooth (i.e., unkeeled), or at most, weakly keeled; dorsal body color uniform (black, green, olive, tan, red, blue, brown, gray), patterned with small black dots and/or light mid-dorsal stripe on brown dorsum, patterned with large reddish blotches on light dorsum, or patterned with dark blotches on gray background; golden neck ring might occur on snakes with otherwise uniformly dark dorsum………………………………………………………………..….....27 Dorsal scales keeled; lateral scales keeled or unkeeled; dorsal body color uniform or dorsum patterned with blotches, crossbands, spots, or dorsal and lateral stripes; light-colored nape patches or neck ring might occur on individuals with light stripes or uniformly-colored dorsum; snout upturned in one species..…….……31 Distinct golden neck ring (sometimes interrupted) with relatively uniformly dark dorsum; venter lighter with irregular spots; anal plate divided; young similar to adults but darker in body color; total length (tip of snout to tip of tail) to 36 cm …...……….………….………….…………Diadophis punctatus (ringneck snake) Neck ring absent, or if ring or collar is present, then numerous blotches occur on dorsum ……………………..…………….…………………………………........28

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Large reddish or brown blotches on light-colored dorsum; blotches extend from head to tip of tail; venter checkered with black and white pattern; anal plate undivided; neck collar may be present; Y- or V-shaped patch may occur on nape; total length to 71 cm….…..……………….Lampropeltis triangulum (milk snake) If dorsal blotches occur, they are gray to brown on a gray background, and blotches are absent from tail; otherwise, color of dorsum is uniform, or a light mid-dorsal stripe and/or small black dots are present …………………………...29 Dorsal color of adults usually bright green, but rarely tan (green color fades to gray-blue after death); white to yellowish venter; anal plate divided; newlyhatched young have dark olive to gray body color; total length to 51 cm).……………………………….……Opheodrys vernalis (smooth green snake) Dorsal color dark green, olive, blue, brown, gray, or black; numerous blotches may be present, but blotches are absent from tail; a middorsal stripe and/or tiny black dots may be present on snakes lacking large blotches.….……...…...….....30 Adult dorsal color uniform dark green, olive, blue, brown, or black; venter color white to bright yellow; anal plate divided; young have gray to brown mid-dorsal blotches on background of gray to bluish gray, and small dark spots on flanks and venter; tail of young is nearly unpatterned; body color pattern nearly absent when body length reaches 76 cm; total length to 127 cm...….Coluber constrictor (racer) Dorsum gray, reddish, or brown; tiny black dots and/or light-colored mid-dorsal stripe sometimes present; venter white to yellowish; scales may be weakly keeled; anal plate undivided; total length to 25.4 cm ….………………………...……..………...Virginia valeriae (smooth earth snake) Anal plate undivided; dark blotches on yellowish dorsum, or one or more welldefined stripes usually present on dorsal or lateral regions of snake; stripes occasionally absent or broken into parallel rows of spots………...……..…...….32 Anal plate divided; snout might be upturned; dorsum of uniform color, blotched, striped, or with parallel rows of spots; light spots might occur on nape, or a ring might encircle the neck………..……………………………..………………..…37 Dark blotches on yellowish dorsum, with strongest contrast at both ends of snake; dark line from eye to angle of jaw; pointed head; hatchlings may be grayish in color; total length to 183 cm...……………… Pituophis melanoleucas (bullsnake) Stripe(s) on dorsal and/or lateral regions of snake (sometimes difficult to see); lateral stripe occasionally broken into spots..….…….…..………………………33 Typically, dorsum uniformly dark colored with one broad, yellowish stripe on lateral region; venter same color as lateral stripes, and sometimes patterned with central row of dark spots; melanistic form occurs in which lateral stripes are absent or difficult to see and the venter is dark colored; total length to 71 cm ……………………………........……Regina grahamii (Graham’s crayfish snake) Stripes on dorsal and lateral regions of snake; in some individuals, dorsal stripe poorly defined and lateral stripes are broken into spots ………………..…...…..34 5

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Lateral stripe usually present on scale rows 2 and 3; dorsal and lateral stripes occasionally absent or broken into spots.……………….……………....…….…35 Lateral stripe on scale rows 3 and 4; dorsal and lateral stripes present….….…...36 Well defined black half-moon marks on venter; lateral stripe often grayish; middorsal stripe white, yellow, orange, or light gray; small head; hatchlings lack these body markings; total length to 38 cm …..……………………………………….. Tropidoclonion lineatum (lined snake) Venter without half-moon marks; lateral stripe on scale rows 2 and 3; stripes usually yellowish but variable in color (stripes often blue after death); middorsal and lateral stripes occasionally broken into spots; total length to 66 cm ……………….………………….......Thamnophis sirtalis (common garter snake) Long, slender tail; light-colored lateral stripe on scale rows 3 and 4; dorsal stripe usually orange in color; dorsum blackish; unmarked venter; total length to 76 cm…….………….……………….Thamnophis proximus (western ribbon snake) Black bars on yellow upper lip; dorsal stripe yellow or orange; dorsal color black, brown, greenish or reddish; lateral stripes may be bluish or greenish; rows of large black spots between stripes; venter unamarked or with random peppering of black; total length to 71 cm….………..…Thamnophis radix (plains garter snake) Upturned snout; dorsum usually spotted, but may be of one color; broad neck stripes usually present; spreads neck and plays dead when threatened; total length to 84 cm ……………..….………..Heterodon platirhinos (eastern hognose snake) Snout not upturned…………………………….………………………...…….…38 Dorsum of adults uniformly black, or black with faint traces of spotted pattern; light-colored chin and throat; dorsal scales weakly keeled, and lateral scales unkeeled; venter with checkered pattern; dorsum of young (< 1 m body length) with black or dark brown blotches on white or light gray background (including tail); total length to 183 cm…………..……..…..Elaphe obsoleta (black rat snake) Dorsum, chin and throat not colored and patterned as above………..…..………39 Dorsum yellow to light brown, with brown or black blotches; dorsal scales weakly keeled; lateral scales unkeeled; venter checkered with black; head usually boldly marked with black lines, the most conspicuous of these being the line that travels diagonally from the eye to the angle of the jaw, and the line on top of the head connecting the eyes; young are noticeably paler than adults, having light brown or gray ground color and lighter body blotches with black outlining; total length to 137 cm……….………...….…………..…….Elaphe vulpina (fox snake) Dorsum uniformly colored, or with blotches, bands, stripes, or small spots in parallel rows; light spots might occur on nape, or a ring might encircle the neck; if blotches or bands are present on dorsum, then dorsal and lateral scales are strongly keeled; if small spots are present on dorsum, then downward-oriented dark streak occurs on side of head and venter is unpatterned ………….....…..…40

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Blotches or crossbands usually occur on dorsum, but fade with age so that very large individuals can appear to have a uniformly dark-colored dorsum; venter often patterned with reddish, brown or black crescent-shaped markings on a white background; hatchling dorsum has a gray or very light brown ground color with striking black or dark brown bands and blotches; total length to 107 cm ………………………………………..….Nerodia sipedon (northern water snake) Dorsum uniformly colored, striped, or with small spots in parallel rows; light spots occur on nape, a light band encircles the neck, or a downward-oriented dark streak occurs on side of head; venter unpatterned and often brightly colored …..41 Venter bright red, orange, or yellow (fades after death); white spots usually occur on nape; dorsum uniformly dark-colored, or with dark lateral and/or dorsal stripes; total length to 25 cm……...…Storeria occipitomaculata (redbelly snake) Downward-oriented dark streak on side of head; dorsum brown with light dorsal stripe and parallel rows of small spots; venter unpatterned and light pink or tan in color; young have light band encircling neck and may lack other body markings; total length to 33 cm..……....…………………..…Storeria dekayi (brown snake)

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References Altig, R. 1970. A key to the tadpoles of the continental United States and Canada. Herpetologica 26: 180-207. Christoffel, R., R. Hay, and L. Ramirez. 2000. Snakes of Wisconsin. Wisconsin Department of Natural Resources, Madison. PUB-ER-100 00. Christoffel, R., R. Hay, and M. Wolfgram. 2000. Amphibians of Wisconsin. Wisconsin Department of Natural Resources, Madison. PUB-ER-105 00. Christoffel, R., R. Hay, and L. Ramirez. 2002. Turtles and lizards of Wisconsin. Wisconsin Department of Natural Resources, Madison. PUB-ER-104 2002. Conant, R., and J.T. Collins. 1998. Reptiles and amphibians of eastern and central North America. Houghton Mifflin Company, Boston, Massachusetts. Iowa Herpetology. Available at http://www.herpnet.net/Iowa-Herpetology. November, 2004. Parmalee, J.R., M.G. Knutson, and J.E. Lyon. 2002. A field guide to amphibian larvae and eggs of Minnesota, Wisconsin, and Iowa. U.S. Geological Survey, Biological Resources Division, Information and Technology Report USGS/BRD/ITR-20020004, Washington, DC. USGS Northern Prairie Wildlife Research Center. Checklist of amphibian species and identification guide. Available at http://www.npwrc.usgs.gov/narcam/idguide. November 2004. USGS Patuxtent Wildlife Research Center. Tadpoles of the United States and Canada: a tutorial and key. Available at http://www.pwrc.usgs.gov/tadpole/. November 2004.

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