American toad

American toad (Anaxyrus americanus)

The American toad is a common and widely distributed amphibian species found throughout the eastern half of Canada and the United States. It is recognized for its adaptability to various habitats and its distinct physical characteristics, including variable skin coloration and a characteristic trilling call during the breeding season.

Life Cycle and Reproduction

The American toad's life cycle begins with eggs laid in two long ropes, which can extend up to 60 meters. These eggs hatch within 3 to 12 days into small tadpoles with round black bodies and slender tails. Tadpoles reach adulthood in approximately 50 to 65 days. Upon metamorphosis, young toads, or toadlets, may remain in the water briefly before transitioning to a predominantly terrestrial existence. They often migrate in groups to shaded, mid-range, and upland forests bordering their breeding marshes. Tadpoles have natural defenses against predators, including swimming in shallow, vegetated waters, schooling behavior, and the production of toxic skin secretions that deter some predators.

Appearance and Characteristics

Adult American toads exhibit considerable variation in color and pattern, with their skin color changing based on habitat, humidity, stress, and temperature. Colors can range from yellow to brown to black, appearing solid or speckled. The eastern American toad, a subspecies, typically measures 5–9 cm in length, though larger individuals have been recorded. A notable feature is the presence of parotoid glands behind the eyes, which secrete bufotoxin, a mild poison that can irritate human skin and mucous membranes and is dangerous to smaller animals if ingested. While generally nocturnal, juveniles may be active during the day, and toads become particularly active during rainfall.

Habitat and Behavior

American toads thrive in diverse environments, including forests and grasslands, provided there is access to semi-permanent freshwater ponds or pools for breeding and water supply, along with dense vegetation for cover and hunting. They are known to be "creatures of habit," often staying within a specific territory that includes wooded areas with water nearby. For shelter, they commonly utilize burrows, under boardwalks, flat stones, logs, or wood piles. During winter, they hibernate by burying themselves in the dirt.

Diet

The diet of adult American toads is varied, consisting of numerous small invertebrates. Commonly consumed prey includes crickets, mealworms, earthworms, ants, spiders, slugs, centipedes, and moths. This broad diet contributes to their survival across different environments.

Subspecies and Identification

The American toad is divided into three subspecies: the eastern American toad (A. a. americanus), the dwarf American toad (A. a. charlesmithi), and the rare Hudson Bay toad (A. a. copei). Distinguishing between subspecies and similar species, such as Fowler's toad or the Canadian toad, relies on specific features like the number of warts in dark spots, the presence or absence of a spotted belly, and the formation of cranial crests.