Anaxyrus baxteri

The Wyoming toad or Baxter's toad (Anaxyrus baxteri, formerly Bufo baxteri) is an extremely rare amphibian that exists only in captivity and within Mortenson Lake National Wildlife Refuge in Wyoming in the United States. The Wyoming toad was listed as an endangered species in 1984, and listed as extinct in the wild since 1991. Before the sharp declines occurred, this toad was classified as a subspecies of the Canadian toad. The Wyoming toad, common up until the 1950s, became significantly fewer in number in the late 1970s, especially between the years of 1975 to 1978. Two years later, in 1980, experts estimated that there were approximately 25 individuals remaining in the wild. Before this sharp decline in population, Wyoming toads were commonly found in the floodplains, ponds, shallow lakes, and seepage pools within the Laramie Basin located in Albany County, Wyoming. Researchers had noted that the species was found abundantly in the region since 1952. However, starting in 1975, Baxter & Stromberg noticed that the population of the Wyoming toad had decreased significantly. Their extreme rarity, documented between 1976 and 1978 revealed no remaining wild populations. The Wyoming toad is dark brown, gray or green color with small dark markings on underside. It carries small rounded blotches warts on its dorsal surface as well as blurry light lines. The male toads have a dark throat. The individual toads can be identified by the variation in their skin colors and wart patterns. The toads can grow up to 5.6 cm (2.2 inches) in length and females grow slightly larger than males. It also has sensitive skin that has low adaptability. Due to the fact that it has sensitive skin, it is easily infected with chytrid fungus, a strong threat to the Wyoming toads. The toad cannot handle the rapid climate change, and cannot adapt to different amounts of water irrigation or diverged irrigation. The toad is mainly active at night and has very poor eyesight. It only relies on the movement of the prey to hunt. The Wyoming toad frequents floodplains and the short grass edges of ponds, creeks, and lakes. They frequently use abandoned pocket gopher and ground squirrel burrows as hibernacula. Habitat typical characteristics can be seen to vary among the different ages of the Wyoming toad. Studies at Mortensen Lake in Albany County, Wyoming, USA show that adult Wyoming toads tend to be more attracted towards habitats with greater vegetation while younger toads are more drawn to areas of lesser. Adults tend to drift further inland away from shorelines, while younger toads tend to settle closer to the shorelines. Through these habitat variations and substrate conditions varying accordingly, adults are seen located in areas with slightly cooler temperatures. For the typical adult conditions, substrate surface temperatures were seen to be 20.31 degrees Celsius (68.55 degrees Fahrenheit) versus 23.05 degrees Celsius (73.49 degrees Fahrenheit) for younger. Adult Wyoming toads demonstrate very little change in location, directing thought towards a much enjoyed dense vegetation environment. (Parker and Anderson, 439-46). If one were to go in search of a Wyoming toad, substrate surface temperatures and distance from shorelines tend to be best indicators of possible sightings. When surface temperatures exceed 20 degrees Celsius and the shoreline is within 1–2 miles, optimal locating conditions are achieved. (Parker and Anderson, 439-46) Toads emerge from hibernation in early May to go to the north shore for mating. They return to the souths shore by late September or early October for hibernation. The younger toads of the year were active up to one month later than older toads which gives them more time to store energy for hibernation and reduce intraspecific competition.The mating calls of the Wyoming toad has a low frequency along with a slow pulse rate, but the duration is longer than that of other types of toads.Wyoming toads mature earlier in age with males at only two years and females at three years, than other, higher-elevation bufonids in the area they occupied in Wyoming.Disease has played a major role in the decline of the Wyoming toad. 'Bacterial infections ('red leg'), fungal infections (chytrid fungus), edema syndrome, and short tongue syndrome' are problems that have been observed in the past. Mycotic dermatitis is seen as the cause of death in toads, but the pathogen was later identified to be chytrid fungus. The chytrid fungus is a major part of the decline of the boreal toad in the Rocky Mountains and is thought to have also played a major role in the decline of the Wyoming Toad.The Wyoming toad mainly eats crickets and mealworms, found on the lake they live near.