Keys to the Amphibians & Reptiles of NH
How to Use The Keys
These keys use the process of elimination. The questions must be answered in numerical sequence - just finding a character that matches your specimen somewhere in a key will not necessarily identify it for you. Starting with question number 1, follow the path directed by the "Go to question #" statement after each choice that matches your specimen. You must follow the numerical sequence, because the characters used to identify the species are not exclusive. That is, an animal identified early in the key may share the characters used to identify other animals later. For example, both Spring Peepers and Gray Treefrogs have expanded discs on the tips of their toes, to help them climb. However, this character can be used in question 4 (see Key to Adult Frogs), to identify the Gray Treefrog because the Spring Peeper had already been eliminated as a possibility in question 3.
Since most species are quite variable, the key will not necessarily identify every individual you find, but it should help you make a pretty good guess. Be especially careful if you think you've identified an animal noted as "Extremely Rare in NH!"
The keys are for use in identifying live animals. Most of the key characters are easily seen. The exceptions are the ridge (keel) on the scales on the back of some small snakes, and some of the characters of larval amphibians. A hand lens (or a reversed camera lens) should magnify these characters enough to make them visible. If you don't want to pick up a snake to look at its belly, use a stick to gently lift it enough to give you a glimpse of its underside.
Key to Amphibians of New Hampshire
Use the tabs in the panel below to view specific keys
Are scales present?
Yes? It's a reptile. Go to the tab Key to Snakes or the Key to Turtles.
No? It's an amphibian.
1. Is a tail present?
Yes? Go to question 2.
No? Go to the tab Key to Adult Frogs.
2. Does the tail have a fin on it?
Yes? Go to question 3.
No? Go to the tab Key to Adult Salamanders.
3. Are there bush-like gills sticking out of the head?
Yes? Go to the tab Key to Larval Salamanders.
No? Go to the tab Key to Larval Frogs.
Introduced, Hypothetical, and Escaped Species: Some of you may encounter some weird herps out there. Exotic species are brought into the state as pets or laboratory animals. It is inevitable some individuals will escape. Fill out a data card and take careful photographs and notes on what you observe.
*Adapted from the Massachusetts Herp Atlas Project, Massachusetts Audubon Society. Used with permission.
Keys to Adult Salamanders
1. Are there small black-bordered red spots on the back?
Yes? It's an Eastern Newt.
No? Go to question 2.
2. Is there a light line running from the back of the eye to the angle of the jaw?
Yes? It's a Dusky Salamander.
No? Go to question 3.
3. Is there a conspicuous constriction at the base of the tail? Are there only 4 toes on each hind foot?
Yes? It's a Four-Toed Salamander.
No? Go to question 4.
4. Is there a dark ridge running from each eye to the nostril?
Yes? It's a Spring Salamander.
No? Go to question 5.
5. Is there a red stripe (not brownish yellow) down the back?
Yes? It's a Redback Salamander, in one of its color forms.
No? Go to question 6.
6. Is there a dark line running from each eye to the tail?
Yes? It's a Two-lined Salamander.
No? Go to question 7.
7. Are there prominent round yellow spots arranged roughly into two irregular rows down the back?
Yes? It's a Spotted Salamander.
No? Go to question 8.
8. Are there silvery crossbands on the back?
Yes? It's a Marbled Salamander. (Extremely rare in NH!)
No? Go to question 9.
9. Is the entire belly (not just the sides) mottled about equally with black and white?
(Does it look like "salt & pepper"?)
Yes? It's a Redback Salamander. (They're not always redbacked!)
No? Go to question 10.
10. Are there more than 14 vertical grooves on the sides of the trunk?
(This is unlikely; you can probably go directly to question 11.)
Yes? It's a Slimy Salamander. (Extremely rare in NH!)
No? Go to question 11.
11. Is the area around the vent (just behind the rear legs) gray? OR Is the area around the vent black?
GRAY? It's a Jefferson Salamander, or a similar hybrid.
BLACK? It's a Blue-spotted Salamander, or a similar hybrid.
Keys to Larval Salamanders
1. Does the tail fin extend forward on the back well past the hind legs?
Yes? It's a pond-type salamander. Go to question 2.
No? It's a stream-type salamander. Go to question 6.
2. Pond-type Salamanders - Larvae with tail fins extending forward onto the body.
Are there four toes (not five) on each rear foot? (Look very carefully; the fifth toe on many salamander larvae is just a tiny bud.) Does the tail fin extend only about half way up the body (not almost all the way forward to the base of the gills)?
Yes? It's a Four-toed Salamander.
No? Go to question 3.
3. Are the sides of the body smooth, with no sign of vertical grooves? Is there a dark stripe on the side of the head, from the nostril to the gills?
Yes? It's an Eastern Newt.
No? Go to question 4.
4. Does the throat have a lot of dark pigment on it?
Yes? It's a Marbled Salamander. (Extremely rare in NH!)
No? Go to question 5.
5. Is the head distinctly wider than the body?
Yes? It's from the Jefferson/Blue-spotted Salamander complex.
No? It's a Spotted Salamander.
6. Stream-type Salamanders - Larvae with tail fins that do not extend forward past the hind legs. Are there only four toes on the rear feet? (Look very carefully; the fifth toe on many salamander larvae is just a tiny bud.)
Yes? It's a Mudpuppy - a sexually mature larva. (Extremely rare in NH!)
No? Go to question 7.
7. Are there either light spots or a pale stripe on the back?
Yes? Go to question 8.
No? It's a Spring Salamander.
8. Are the stalks of the gills longer than the gill filaments attached to them? Are the filaments attached neatly to the bottom edge of the stalk? OR Are the gill stalks shorter than the filaments attached to them? Are the filaments attached to the stalk in no particular pattern?
Longer gill stalks with filaments on bottom edge? It's a Two-lined Salamander.
Shorter gill stalks with filaments irregularly attached? It's a Dusky Salamander.
Redback and Slimy Salamanders don't have an active larval stage.
Keys to Adult Frogs
1. Is there a large gland behind each eye? Are there prominent warts on the back?
Yes? It's a toad; Go to question 2.
No? It's another type of frog. Go to question 3.
2. Toads - Frogs with prominent warts.
Do some of the dark spots on the back have three or more warts in them?
Is there only one spot, or no spot at all, on the chest?
OR Are there only one of two warts in each spot on the back?
Is there dark spotting on the chest?
Three+ warts per spot & 0-1 chest spots? It's a Fowler's Toad.
One-two warts per spot & mottled chest? It's an American Toad.
3. Other Frogs - Frogs without prominent warts. Is there an X on the back?
Yes? It's a Spring Peeper.
No? Go to question 4.
4. Are the tips of all the toes expanded into discs?
Yes? It's a Gray Treefrog.
No? Go to question 5.
5. Is there a dark "robber's mask" extending behind the eye?
Yes? It's a Wood Frog.
No? Go to question 6.
6. Is there a thickened ridge of skin curving around the ear drum, but no other thickened ridges extending down the back?
Yes? It's a Bullfrog.
No? Go to question 7.
7. Are there squarish or rectangular spots (not round or oval) arranged in two regular rows down the back? Are the undersides of the legs bright orange or yellow?
Yes? It's a Pickerel Frog.
No? Go to question 8.
8. Are there discrete light-edged circular or oval spots on the back and sides (not just dark mottling)?
Yes? It's a Northern Leopard Frog.
No? Go to question 9.
9. Are there dark, somewhat regular crossbands on the hind legs? Does the fifth (outside) toe of the hind foot extend past the webbing?
Yes? It's a Green Frog.
No? It's a Mink Frog, which smells like a mink or rotten onions.
Keys to Larval Frogs
1. Find the vent: it's a little tube sticking out of the underside of the body at the base of the tail fin. Does the vent run down through the middle of the tail fin? OR Does the vent extend down on the right side of the tail fin?
Vent in the middle? It's a toad. Go to question 2.
Vent on the right? It's another type of frog. Go to question 3.
2. Toads - Tadpoles with vents in the middle of the fin. Is the back mottled? OR Is the back uniformly dark?
Mottled Back? It's a Fowler's Toad.
Uniform Back? It's an American Toad.
3. Other Frogs - Tadpoles with vents on the right of the fin. Does the tail have red on it?
Yes? It's a Gray Treefrog.
No? Go to question 4.
4. When viewed from above, do the eyes appear to be on the side of the head (do they touch, or almost touch, the outline of the body)? OR Do the eyes appear to be definitely on top of the head when viewed from above?
Eyes on the side? It's a Spring Peeper.
Eyes on the top? Go to question 5.
5. Is there a light stripe on the side of the head, from the mouth to behind the eye? Are there four (not three or less) little strips of teeth below the mouth?
Yes? It's a Wood Frog.
No? Go to question 6.
6. Is the horny part of the lower jaw almost totally colored with dark pigment? Are the intestines clearly visible through the skin?
Yes? It's either a Pickerel Frog or a Northern Leopard Frog.
No? Go to question 7.
7. Are there small circular black dots on the tail, confined to the upper half of the tail?
Yes? It's a Bullfrog.
No? Go to question 8.
8. Are the tail muscles much paler than the body? OR Are the tail muscles about as dark as the body?
Pale tail muscles: It's a Mink Frog.
Dark tail muscles: It's a Green Frog.
Keys to Snakes
1. Does it make a rattling sound?
Yes? It's either nonvenomous or a rattlesnake. Go to question 2.
No? It's either nonvenomous or a rattlesnake. Go to question 2.
Many nonvenomous snakes vibrate their tails to produce a rattling sound. Conversely, rattlesnakes may have their rattles broken off, or just may not rattle when approached.
2. Is there a hard, rounded button or a rattle at the tip of the tail? Is the head uniformly colored (no blotches), with some regular scales between the eyes (regular scales are unenlarged scales just like those on the back)? Is the tail black, like velvet? Is there a pit between the eye and the nostril? (Use binoculars to look for the pit and the scales on the top of the head. Please don't kill the snake!)
Yes? It's a Timber Rattlesnake - An ENDANGERED SPECIES in NH.
No? It's a nonvenomous snake. Go to question 3.
3. Are there yellow or yellowish stripes down the back?
Yes? It's a Garter or Ribbon Snake. Go to question 11.
No? Go to question 4.
4. Is there a collar, ring, or set of light spots around the neck?
Yes? It's a Brown, Redbelly or Ringneck Snake. Go to question 12.
No? Go to question 5.
5. Is the snout sharply pointed and upturned?
Yes? It's an Eastern Hognose Snake.
No? Go to question 6.
6. Is there a light V or Y shaped mark on the back of the head? Does the belly have a black and white checkerboard pattern?
Yes? It's a Milk Snake.
No? Go to question 7.
7. Does the belly have dark or reddish semicircular halfmoon marks?
Yes? It's a Northern Water Snake.
No? Go to question 8.
8. Are there brown blotches down the middle of the back that get smaller toward the tail?
Yes? It's a young Racer.
No? Go to question 9.
9. Is there a dark vertical streak on the side of the head behind the eye? Are there two rows of little dark spots running down the back?
Yes? It's a Brown Snake.
No? Go to question 10.
10. Is the animal solid black all over? OR Is it green or blue-gray?
Black? It's a Racer.
Green, Olive, Blue-Gray? It's a Smooth Green Snake.
11. Garter Snakes/Ribbon Snakes - Snakes with yellow stripes.
Is there at least one row of small indistinct dark spots on each side of the belly? OR Is the belly unmarked?
Spots at side of belly? It's a Common Garter Snake.
Unmarked belly? It's an Eastern Ribbon Snake.
12. Brown/Redbelly/Ringneck Snakes - Snakes with yellow stripes.
Is there at least one row of small indistinct dark spots on each side of the belly? OR Is the belly unmarked?
Yes? It's a redbelly Snake.
No? Go to question 13.
13. Is the belly pale? Do the scales on the back have a little ridge (keel) on them? OR Is the belly yellow? Are the scales on the back completely smooth?
Pale belly & keeled scales? It's a young Brown Snake.
Yellow belly & smooth scales? It's a Ringneck Snake.
Keys to Turtles
1. Does the tail have a saw-toothed ridge on the top?
Yes? It's a Snapping Turtle.
No? Go to question 2.
2. Is there red on the edges of the back shell?
Yes? It's a Painted Turtle.
No? Go to question 3.
3. Are there two light lines on the face, but no red or orange on the shell? Is the belly shell too small to protect the legs?
Yes? It's a Common Musk Turtle.
No? Go to question 4.
4. Does the back shell have a saw-toothed rear edge?
Yes? It's a Wood Turtle.
No? Go to question 5.
5. Is there a low, colored ridge running down the center of the back shell? Can the turtle completely enclose itself inside its shell? Does the upper jaw curve down in front to form a hooked beak? (This is unlikely, you can probably go directly to question 6.)
Yes? It's an Eastern Box Turtle. (Extremely rare in NH!)
No? Go to question 6.
6. Are the chin and throat a solid bright yellow? Is a hinge present on the belly shell? OR Are there only some small orange or yellow spots on the head? Is there no sign of a hinge across the belly shell?
Yellow throat & hinge present? It's a Blanding's Turtle.
Spotted head & no hinge? It's a Spotted Turtle.