Colorado's Amphibians |
by Lauren J. Livo |
Evaluate the criteria below to identify a species. |
1a. | Adult with long tail, aquatic larvae with conspicuous gills on sides of head. | Ambystoma tigrinum Tiger salamander |
1b. | Adult lacking tail. | go to 2 |
2a. | Skin warty, prominent parotoid glands behind eyes. | go to 3 |
2b. | Skin relatively smooth, no parotoid glands. | go to 7 |
3a. | Light mid-dorsal stripe. | go to 4 |
3b. | No light mid-dorsal stripe. | go to 6 |
4a. | Large symmetrical dark blotches on back. | Bufo cognatus Great Plains toad |
4b. | Not as above. | go to 5 |
5a. | No cranial crests, usually above 8,000'. | Anaxyrus boreas boreas Boreal toad |
5b. | Cranial crests, usually below 7,000'. | Bufo woodhousii Woodhouse's toad |
6a. | Parotoid glands nearly circular, body tan or gray with red warts. | Bufo punctatus Red-spotted toad |
6b. | Body green with scattered dark spots. | Bufo debilis Green toad |
7a. | Head small with fold of skin behind eyes. | Gastrophryne olivacea Great Plains narrowmouth toad |
7b. | Not as above. | go to 8 |
8a. | Vertical pupils; rear feet each with single, hard dark 'spade'. | go to 9 |
8b. | Pupils and rear feet not as above. | go to 12 |
9a. | Boss between eyes. | go to 10 |
9b. | No boss between eyes. | go to 11 |
10a. | Boss hard, mostly eastern Colorado. | Spea bombifrons Plains spadefoot |
10b. | Boss pliable, western Colorado. | Spea intermontana Great Basin spadefoot |
11a. | Body greenish-yellow with dark blotches; snout-vent length may exceed 2.5 inches. | Scaphiopus couchii Couch's spadefoot |
11b. | Body gray or brown with dark spots; snout-vent length up to 2.5 inches. | Spea multiplicata New Mexico spadefoot |
12a. | Conspicuous dorsolateral folds. | go to 13 |
12b. | No dorsolateral folds. | go to 15 |
13a. | Dark mask through eye from snout to angle of jaw, usually light mid-dorsal stripe, north-central Colo. | Rana sylvatica Wood frog |
13b. | No mid-dorsal stripe, dark spots on body. | go to 14 |
14a. | Dorsolateral folds continuous from eye to groin, body green or brown. | Rana pipiens Northern leopard frog |
14b. | Dorsolateral folds broken and inset near groin, body always brown. | Rana blairi Plains leopard frog |
15a. | Toepads distinctly enlarged. | Hyla arenicolor Canyon treefrog |
15b. | Not as above. | go to 16 |
16a. | Fold of skin around top of eardrum; body size may exceed 7 inches. | Rana catesbeiana Bullfrog |
16b. | Maximum body size less than 1.5 inches. | go to 17 |
17a. | Stripe through eye from snout to groin, usually three stripes on back (may be spotted), little webbing on hind feet. | Pseudacris triseriata Chorus frog |
17b. | Triangular spot between eyes, extensive webbing on hind feet. | Acris crepitans Northern cricket frog |