Herpetology example

Cortland Herpetology Connection

Frog Key

See also species distribution maps at the New York State
Amphibian and Reptile Atlas Project website.

Key to the families of adult frogs in New York

1.a.Pupil of eye verticalPelobatidae
1.b. Pupil horizontal2

2.a. Parotoid glands present Bufonidae
2.b. Parotoid glands absent 3

3.a. Intercalary cartilage between last two phalanges of the toes, some with pads at toe tips Hylidae
3.b. No intercalary cartilage, no toe pads Ranidae

Key to the species of the family Pelobatidae of New York

1.a. Only species found in New York Eastern Spadefoot toad
Scaphiopus holbrookii

Key to the species of the family Bufonidae of New York

1.a. One or two warts in each dark spot on back, warts
on shank generally larger than those on thigh		 American toad
Bufo americanus
1.b. 3-4 warts in each dark spot on back, warts on shank
not larger than those on thigh 		Fowler's toad
Bufo fowleri

Key to the species of the family Hylidae of New York

1.a. Slight webbing on hind foot, smooth skin 2
1.b. Extensive webbing on hind foot, warty skin 3

2.a. Slender dark X on back, dark triangle between eyes, toe pads moderate in size Spring peeper
Pseudacris crucifer
2.b. Approximately three dark stripes on back, pale upper lip, narrow head, toe pads small Western chorus frog
Pseudacris triseriata

3.a. Toe pads large, distinct dark dorsal blotches, light spot beneath eye, often orange inside thighs Gray treefrog
Hyla chrysoscelis/versicolor
3.b. Toe pads absent, dark triangle between eyes, irregular blotches on back, dark line along thigh Northern cricket frog
Acris crepitans

Key to the species of the family Ranidae of New York

1.a. Distinct dorsal spots present 2
1.b. No distinct dorsal spots 4

2.a. Dorsal spots square and in paired rows along back, often yellow or orange inside thighs Pickerel frog
Rana palustris
2.b. Dorsal spots rounded, not paired 3

3.a. Pointed snout, usually a white spot on tympanum,
usually no dark spot above snout		 Southern leopard frog
Rana sphenocephala
3.b. Snout less pointed, no white spot on tympanum, usually a dark spot above snout Northern leopard frog
Rana pipiens

4.a. Dark mask beneath eye and enclosing tympanum,
dorsolateral ridge distinct, body uniformly tan or brown		 Wood frog
Rana sylvatica
4.b. No mask 5

5.a. Webbing reaches tip of 4th hind toe, hind legs with dark spots or blotches, tympanum smaller than or equal to size of eye Mink frog
Rana septentrionalis
5.b. Webbing fails to reach tip of 4th hind toe, hind legs often with dark cross bands, tympanum equal to or greater than eye 6

6.a. Dorsolateral ridge present on body Green frog
Rana clamitans
6.b. Dorsolateral ridge absent Bullfrog
Rana catesbeiana