Frogs of the United States and Canada, 2-vol. set

Family Bufonidae

Family Bufonidae Anaxyrus americanus (Holbrook, 1836) American Toad Crapaud d’Amérique ETYMOLOGY americanus: Latinized name for America, meaning of or belonging to America. NOMENCLATURE Conant and Collins (1991): Bufo americanus Synonyms: Bufo americanus copei, Bufo copei, Bufo lentiginosus, Bufo lentiginosus americanus , Bufo terrestris americanus, Bufo terrestris charlesmithi, Chilophryne americana, Incilius americanus IDENTIFICATION Adults. This is a medium to large toad (normally ca. 50–90 mm SUL; maximum 155 mm SUL, Harding, 1997); females may be much larger than males. The dorsum is gray, olive brown, or a rich brown to nearly brick red, and it is well covered with knobs and bumps; the elliptical parotoids and cranial crests are prominent, with postorbital branches of the cranial crests extending posteriorly in front of the parotoid gland. There is usually one knob or wart per dark spot. Some individuals have a cream to yellow line extending from the head down the middle of the back. The bellies are white with some mottling around the sides, although there is considerable geographic variation in the extent of ventral spotting or mottling (Blair, 1943a). The most extensive ventral mottling is found on northern toads. Limbs are short and stocky, in keeping with its hopping and walking mode of travel, and the hind feet are moderately webbed between the digits. Males have a dark subgular vocal sac, and they have nuptial pads on the thumb during the breeding season. The iris of the eye is bronze or gold. Juveniles are colored like adults, but their skins are much smoother, the cranial crests are not as prominent, and the tympanum is not evident. Albino American Toads have been collected in Minnesota (Oldfield and Moriarty, 1994) and Virginia (in Dyrkacz, 1981). Sexual size dimorphism is present, with males being smaller than females (Wilbur et al., 1978; Minton et al., 1982). In Indiana, northern animals are larger (males 65–80 mm SUL; females 75–87 mm SUL) than southern animals (males 50–65 mm SUL; females 60–75 mm SUL) (Minton et al., 1982). In central Indiana, males averaged 62.8 mm and females 72.7 mm (Howard, 1988a). Other records include: males averaging 67 mm SUL (range 59 to 78 mm) and females 75 mm SUL (64–89 mm) in Ontario (Licht, 1976); males 60–83 mm SUL in Maine (Sullivan, 1992a); males 51–72 mm SUL (mean 61 mm) and females 68–85 mm SUL (mean 75 mm) in Connecticut (Klemens, 1993); males 58–81 mm SUL (mean 68 mm) and females 63–93 mm SUL (mean 84 mm) on Prince Edward Island (Cook, 1967); males 49–76 mm SUL and females 57–105 mm SUL in Nova Scotia (Gilhen, 1984). Blair (1941a) provided mean adult SULs for 18 populations; they ranged from 54.5 to 72.8 mm SUL. Larvae. The tadpole’s dorsum is uniformly dark brown to black without a light mark behind each eye; very fine silvery or gold spots may overlay the ground color; the throat is largely pigmented; the snout is sloping in lateral view; and the eyes are small. The belly may have more extensive aggregations of gold or copper spots than the dorsum or laterally. Tails are short and bicolored. Tail musculature is usually bicolored and is greater in height than either the upper or lower tail fin. 18 BUFONIDAE County in northeast Mississippi, but Lazell and Mann (1991) confirmed its presence along the loess bluffs east of the Mississippi River at least as far north as Regantown. The species appears absent from northwestern Alabama, but is found in northeastern Alabama south through the Coosa Valley. The southern limit of the range generally follows the southern boundary of the upper Piedmont and Blue Ridge Province from east-central Alabama through southeastern Virginia, with isolated populations in coastal North Carolina and the Delmarva Peninsula . It ranges from sea level to nearly 1,800 m in the Southern Appalachians (Dodd, 2004). American Toads are found on islands in western Lake Erie (Langlois, 1964; King et al., 1997; Hecnar et al., 2002), the Apostle Islands of Lake Superior (Bowen and Beever, 2010), Walpole Island in Lake St. Clair (Woodliffe, 1989), northern Michigan including Isle Royale (Ruthven, 1908; Harding, 1997), James Bay (Hodge, 1976), the mouth of the St. Lawrence River (Fortin et al., 2004a), Prince Edward Island (Cook, 1967), Muskeget Island off the coast of Massachusetts (J.A. Allen, 1868), Martha’s Vineyard (Lazell, 1976), and Long Island, New York (Overton, 1914). The species has been introduced into Newfoundland...