American toad
American toad (Anaxyrus americanus)
Taxonomy
| Kingdom | Phylum | Class | Order | Family | Genus | |
|---|---|---|---|---|---|---|
| Classification | Animalia | Chordata | Amphibia | Anura | Bufonidae | Anaxyrus |
Their name has recently changed from (Bufo americanus) to (Anaxyrus americanus).
Description
The American toad is a common toad species that can be found throughout the Eastern and Central parts of the United States and Canada. This species is a medium size toad that grows up to 5-9 cm or 2-4 inches in length with females generally being slightly larger than males. Its coloration can change depending on the temperature, humidity, and stress levels of their environment. American toads are predominantly brown and can display hues of red or olive green. Their bellies are whitish or yellow, usually with dark spots. They have noticeable warts on their skin, including two large ones behind their eyes. The warts behind their eyes are their parotoid glands which are major salivary glands found in animals. These parotoid glands secrete a bufotoxin that is used to deter predators. Bufotoxin is a milky toxin made up of steroid lactones and can cause illness and death in small animals. The bufotoxin in American toads is not fatal to humans but can cause allergic reactions. American toads typically only live to be a year old in the wild, however they can live up to around 10 years old in capacity. There is even a case of an American toad living 36 years in capacity, until it accidentally died due to an accident.
Range and Subspecies
American toads can be found throughout most of the Eastern and Central parts of the United States and Canada. They prefer cool woodlands with lots of moisture, but can live in meadows, fields, and gardens. American toads require small freshwater ponds for their early days when they start as tadpoles. As they develop, they hydrate their bodies by absorbing moisture through their thin skin, so they require a moist environment to survive. There are thought to be three different subspecies of the American toad, including the Eastern American toad (Anaxyrus americanus) and the Dwarf American toad (Anaxyrus charlesmithi). The range of the Dwarf American toad is more concentrated and they are found in more southern states while the Eastern American toad occupies a range spanning the East coast of the United States and Canada, excluding the southernmost states. There is a rare third subspecies that is from the Hudson Bay region, located in the Canadian provinces of Quebec and Ontario.
Life Cycle and Behavior
Depending on temperature and location, mating can being as early as March and ends in July. The males will find a shallow spot in wetlands or ponds and call to attract females. The males generally only call at night but will call during wet days during the peak of mating season. [1] Once the mating takes place the female will lay from 2,000- 20,000 eggs in a long strand. The eggs will hatch after 3-12 days. The eggs hatching usually happens from June to August. Once the eggs hatch they develop into tadpoles and then after about 60 days turn into fully developed toads. While tadpoles are developing they feed on algae. An American Toad will reach sexual maturity after 2-4 years. Once the toads reach adulthood they feed during the early morning into the night. The toads feed on a variety of insects. The toad will often hide in leaf litter to avoid predators. The toads will burrow in moist soils, and hibernate in these burrows during the winter.
Diet and Predators
When American toads start off as tadpoles, they are herbivorous and primarily feed on decaying plants. When they becomes adults, they become carnivorous and eat small creatures such as insects, spiders, worms, and snails. The predators of the American toad include
Eastern hognose snake is immune to toxin, specializes toads
References
Altig, Ronald, et al. Handbook of Larval Amphibians of the United States and Canada. 1st ed., Cornell University Press, 2015. JSTOR, www.jstor.org/stable/10.7591/j.ctt1tm7g59. Accessed 12 Apr. 2021.
(“Eastern American Toad Fact Sheet - Signs of the Seasons: A New England Phenology Program - University of Maine Cooperative Extension”) “IUCN Red List of Threatened Species.” IUCN Red List of Threatened Species, https://www.iucnredlist.org/species/54570/56843565. Accessed 12 Apr. 2021.
Pauly, Gregory B., et al. “THE HISTORY OF A NEARCTIC COLONIZATION: MOLECULAR PHYLOGENETICS AND BIOGEOGRAPHY OF THE NEARCTIC TOADS (BUFO).” Evolution, no. 11, The Society for the Study of Evolution, 2004, p. 2517. Crossref, doi:10.1554/04-208.
Vaughan, Andres, and Joseph R. Mendelson. “Taxonomy and Ecology of the Central American Toads of the Genus Crepidophryne (Anura: Bufonidae).” Copeia, no. 2, American Society of Ichthyologists and Herpetologists (ASIH), May 2007, pp. 304–14. Crossref, doi:10.1643/0045-8511(2007)7[304:taeotc]2.0.co;2.
“IUCN Red List of Threatened Species.” IUCN Red List of Threatened Species, https://www.iucnredlist.org/species/54570/56843565. Accessed 12 Apr. 2021.