Frogs

       Frogs in the Great Smoky Mountains National Park require water for breeding and for tadpole development. As such, the diversity and distribution of frogs are not as great in the mountains as in the adjacent lowlands of the Tennessee

Figure 18. Gum Swamp at Cades Cove in high water.

Valley and Atlantic Coastal Plain. In the Smokies, four major types of breeding sites are used by frogs and toads: ponds (natural, as well as of beaver or human origin); woodland pools; grassy ditches, pools, and rivulets; and larger streams and rivers.

Ponds

       Pond distribution is limited in the Smokies, being confined mostly to Cades Cove,

Figure 19. Gum Swamp at Cades Cove when dry.

Big Spring Cove, and two beaver ponds. The most important frog-breeding ponds are Gum Swamp (figs. 18, 19), Gourley Pond (figs. 20, 21), Methodist Church Pond (fig. 22), and the sewage-treatment pond (all in Cades Cove); the four sinkhole ponds in Big Spring Cove (also known as the Finley-Cane ponds); and the beaver ponds in Bone Valley and Big Cove (fig. 23). Species that commonly use these ponds are the American Toad (Bufo americanus), Cope’s Gray Treefrog (Hyla chrysoscelis),

       Northern Green Frog (Rana clamitans), Pickerel Frog (R. palustris), Wood Frog (R. sylvatica), and Eastern Spadefoot (Scaphiopus holbrooki),

Figure 20. Gourley Pond at Cades Cove in high water.

known only from Gum Swamp. American Bullfrogs (R. catesbeiana) also have been heard at the beaver pond in Big Cove. Some of these ponds dry completely as the summer progresses, particularly Gum Swamp (fig. 19), Gourley Pond (fig. 21), and the Finley-Cane sinkhole ponds.

Woodland Pools

       Woodland pools are scattered at various areas within the Park. They range from a few centimeters deep to about 0.5 m, and they usually dry as summer progresses. Woodland pools are located in level ground at Cosby, Sugarlands,

Figure 21. Gourley Pond at Cades Cove when dry.

Metcalf Bottoms, Big Spring Cove, Little Cataloochee Valley, throughout the Cane Creek drainage (fig. 24), Cades Cove (especially along Abrams Creek at the western edge of the cove), and doubtless in other areas of the Park. Amphibians that use these small pools for breeding include the Eastern Red-spotted Newt (Notophthalmus viridescens), American Toad (Bufo americanus), Cope’s Gray Treefrog (Hyla chrysoscelis), Northern Green Frog (Rana clamitans), Pickerel Frog (R. palustris), and Wood Frog (R. sylvatica).

Grassy Ditches, Pools, and Rivulets

Figure 22. Methodist Church Pond at Cades Cove.

       Grassy ditches, pools, and rivulets are generally shallow, open-canopied habitats, with a grassy vegetation where concealment and breeding sites are available (fig. 25). Only two places in the Park contain much of this habitat: Cades Cove and Cataloochee Valley. Frogs found here include the American Toad (B. americanus); Eastern Narrowmouthed Toad (Gastrophryne carolinensis), known only from grassy pools at the Abrams Creek Ranger Station and at Shields Pond in Cades Cove; Spring Peeper (Pseudacris crucifer); Upland Chorus Frog (Pseudacris feriarum); and the ubiquitous Wood Frog (R. sylvatica). These habitats normally dry rapidly with the warm weather, although the rivulets and some pools in Cades Cove may persist well into summer.

Figure 23. Beaver pond at Big Cove.

Streams and Rivers

       A few species of frogs breed in the shallows of rivers and larger streams. In the Great Smokies, the American Bullfrog’s (R. catesbeiana) large tadpoles are conspicuous in Abrams Creek near the Abrams Creek Ranger Station. Additional species, such as Fowler’s Toad (B. fowleri), breed in the backwaters formed from flooding along streams and rivers. Other frogs, such as Northern Green Frogs (R. clamitans), are found along streambanks during the nonbreeding seasons.

Table 2. Identification and Life History of the Frogs of Great Smoky Mountains National Park [<, less than; >, greater than; mm, millimeter; cm, centimeter; m, meter; m2, square meters] - click to enlarge Species Eggs Tadpole description Breeding times Larval period Metamorph size Acris crepitans eggs deposited singly; 1 gelatinous envelope, >2.3 mm in diameter; deposited in shallow water among stems of grass or on bottom; 250 eggs per complement a medium-sized light to medium-gray tadpole; throat light; tail musculature mottled or reticulated; usually a very distinctive "black flag" on the tail tip; tail long and narrow; anus dextral (to the right); oral disk emarginate; most 30-36 mm total length, rarely to 46 mm April to June, possibly into July 35-70 days, based on Acris crepitans blanchardi 10-15 mm Bufo americanus eggs in strings with gelatinous casings; 2 envelopes present; strings long, to 60 m; 15-17 eggs per 25 mm; 4,000-12,000 eggs on bottom of quiet pools body round or oval in dorsal view; eyes dorsal (looks cross-eyed); nostrils large; color dark brown to black; dorsal portion of the body uni- colored; venter with aggregate silvery or copper spots; snout sloping in lateral view; tail musculature distinctly bicolored; anus medial (in the center); spiracle is distinctly on left side of body spring (March-April) 50-65 days 7-12 mm B. fowleri eggs in strings with gelatinous casings; 1 envelope present and <5 mm in diameter; strings 2.4-3 m with 17-25 eggs per 25 mm; 5,000-10,000 eggs; in tangled mass around vegetation body round or oval in dorsal view; eyes dorsal (looks cross-eyed); nostrils large; color dark; dorsal portion of body slightly mottled; snout rounded in lateral view; tail musculature often not distinctly bicolored; anus medial (in the center); spiracle is distinctly on left side of body April to July 40-60 days 7.5-11.5 mm Gastrophryne carolinensis eggs in small surface film that has a mosaic structure; envelope a truncated sphere; mass round or square; 10-150 eggs per mass; in any depression with water, but not deep pools a small jet-black tadpole with lateral white to pink stripes on posterior portion of body extending to the tail musculature. Viewed from the side, the head comes to a point; body round in dorsal view; eyes wide set and lateral; anus median; jaws do not have keratinized sheaths, and the oral disc and labial teeth are absent mid-May to mid-August 20-70 days 8.5-12 mm Hyla chrysoscelis eggs in small surface film, but envelope not in truncated sphere; no mosaic structure; 5-40 eggs per mass; in shallow ponds attached loosely to vegetation, or free. Air bubbles present. small to medium-sized grayish tadpole with a high dorsal tail fin; dorsal tail fin height equal to or greater than musculature height; tail long, with black blotches; background color of mature tail orange to scarlet; throat rarely pigmented; dorsal fin never extends anterior to midway between the spiracle and eye; anus dextral (to the right); oral disk not emarginate April to June, but calls occasionally heard at other times of the year 45-65 days 13-20 mm Pseudacris crucifer eggs deposited singly in shallow water near bottom among vegetation; one gelatinous envelope. a small-sized deep-bodied tadpole with a medium-sized tail; tail musculature mottled; fins clear or with blotches; no dots on body; snout square when viewed dorsally; anus dextral (to the right); oral disk not emarginate late winter to early spring (February to April); calls occasionally heard at other times of the year 90-100 days 9-14 mm P. feriarum egg mass in lump, but loose irregular cluster; 1 envelope, 3.6-4.0 mm; deposited in marshy areas and pools in matted vegetation small olive to black tadpole with a bronze belly; tail medium; anus dextral (to the right); oral disk not emarginate; tadpoles develop rapidly February to April. 50-60 days 8-12 mm

Table 2. Continued

Table 2. Identification and Life History of the Frogs of Great Smoky Mountains National Park (Continued) [<, less than; >, greater than; mm, millimeter; cm, centimeter; m, meter; m2, square meters] - click to enlarge Species Eggs Tadpole description Breeding times Larval period Metamorph size Rana catesbeiana eggs in large surface film in form of a disc; 10,000-12,000 eggs per disc; deposited among water plants or brush; 1 gelatinous envelope large olive to grayish green tadpole with small widely spaced small spots (dots) covering the body and tail; venter straw; eyes bronze; body oval and round in dorsal view; eyes dorsal or dorsolateral; nostrils small compared with eyes; lower jaw wide; anus dextral (to the right); oral disk emarginate late spring and throughout the summer. Calls may be heard at other times of the year 1-2 years 31-59 mm R. clamitans eggs in surface film; mass <0.09 m2; 1,000-5,000 per mass; attached to vegetation or free; 2 gelatinous envelopes large (but not deep bodied) olive green tadpole with large dark spots, generally with a white throat; belly deep cream without iridescence; body oval and round in dorsal view; eyes dorsal or dorsolateral; nostrils small compared with eyes; tail green mottled with brown; lower jaw wide; anus dextral (to the right); oral disk emarginate late April to late July or even early August. Calls may be heard at other times of the year to 1 year 23-38 mm R. palustris eggs in firm regular cluster; brown above and yellow below; mass a sphere 38-100 mm in diameter; 2 envelopes present; 2,000-4,000 eggs; mass deposited 75-100 mm to 91 cm under water; attached to debris and vegetation large, full, deep-bodied tadpole; olive green shading through yellow on sides; venter cream, back marked with fine black and yellow spots; belly with blotches of white; venter iridescent, viscera visible; tail very dark, black blotches can aggregate to purple-black; body oval and round in dorsal view; eyes dorsal or dorsolateral; nostrils small compared with eyes; lower jaw narrow; anus dextral (to the right); oral disk emarginate late winter to spring (mid- March-April) 70-80 days 19-27 mm R. pipiens mass a firm regular cluster; 3,500-6,500 eggs close together in mass; 2 envelopes present; outer envelope 5 mm; eggs black above and white below; deposited near surface, usually attached to grasses and vegetation, sometimes free large, deep-bodied tadpole; dorsally dark brown, covered with small gold spots; belly deep cream, with bronze iridescence; viscera visible; throat translucent and more extensive than Pickerel Frog; similar in appearance to Green Frog, but darker; body oval and round in dorsal view; eyes dorsal or dorsolateral; nostrils small compared with eyes; lower jaw narrow; anus dextral (to the right); oral disk emarginate probably early March to early May 60-80 days 18-31 mm R. sylvatica eggs in firm regular cluster; black above and white below; mass a sphere 38-100 mm in diameter; 2 envelopes present; 2,000-4,000 eggs; mass deposited 75-100 mm to 91 cm under water; attached to debris and vegetation medium-sized tadpole with usually very dark to gray coloration, and with a faint light stripe of cream, white or gold along the upper jaw (like a mustache); venter cream with belly slightly pigmented at sides; body oval and round in dorsal view; eyes dorsal or dorsolateral; nostrils small compared with eyes; anus dextral (to the right); oral disk emarginate; tail quite long; dorsal crest high extending on to body winter and early spring (mid-December to March) 45-85 days 16-18 mm Scaphiopus holbrooki eggs in loose irregular cylinder or band; mass 25-75 mm wide and 25-305 mm long; deposited on stems of plants/grass; 1 gelatinous envelope; 200 per packet a small dark tadpole, bronze to brown with close-set tiny orange spots; body round or oval in dorsal view; eyes close-set and dorsal, iris black; head wide relative to body width; tail short, with tip blunt and rounded; anus medial (in the center); spiracle is ventrolateral. Often found in "schools" of hundreds of tadpoles only heard calling once (July 12, 1999). Probably any time from March to October 14-60 days 8.5-12 mm

Other Breeding Sites

Figure 24. Woodland drainage pool at Cane Creek.

       Four minor types of wetlands and aquatic sites are used occasionally by frogs for breeding in the Great Smokies. American toads (B. americanus) breed in the backwaters along the north shore of Fontana Reservoir, although reservoirs (fig. 26) are generally depauperate of amphibians. Small, usually closed-canopied, swampy and mucky wetlands (for example, those found along Indian Creek, at Smokemont,

Figure 25. Grassy pool at Cades Cove.

and at the old trout pond in Cataloochee; see fig. 16) are used by Wood Frogs (R. sylvatica). Wood Frogs are quite variable in their choice of breeding sites, even to depositing eggs in human-enlarged spring pools and roadside ditches. Indeed, virtually any pool in late winter to early spring is likely to be colonized by breeding Wood Frogs.

Life History