Tiger salamanders (Ambystoma tigrinum) can live in any habitat - from desert to alpine tundra - as long as there is at least seasonal water to breed in for their larval stage. They can survive in the dunes by burying themselves in moist sand beneath the dry surface. While tiger salamanders on the valley floor often have the characteristic tiger stripes (Ambystoma tigrinum mavortium) a dark green subspecies (Ambystoma tigrinum nebulosum) is found in the forests or tundra of the Sangre de Cristo Mountains. (Find more information on tiger salamander subspecies and distribution from the Colorado Herpetological Society). Tiger salamanders are one of a few amphibian species that can survive long, frigid winters by actually freezing then coming back to life in spring.
Chorus frogs (Pseudacris triseriata) are usually the first amphibians to appear in spring, making loud choruses even when it is still snowing in March and April. Their loud call is similar to running a finger over the hard teeth of a comb - unexpected from a creature that is only about 1 inch (2.5cm) long when fully grown. In the park, their color varies quite a bit, from greyish brown to beige to green. Most individuals have a striped pattern on their back. Like tiger salamanders, chorus frogs have been found at high elevations in Colorado, and have the same ability to completely freeze during winter then thaw out back to activity in spring.
Photo of Dark Green Chorus Frog with Stripes, Twin Lakes, Great Sand Dunes National Park, 2010 (NPS/Patrick Myers)
Northern Leopard Frogs (Rana pipiens)have declined in population over much of North America, with possible causes under investigation by biologists. Some leopard frogs are found in the wetlands of Great Sand Dunes National Park, though they are not common here.
Because of their declining numbers, they are currently listed as a Species of Special Concern by the Colorado Division of Wildlife.
Spadefoots (Spea bombifrons) are in a different family than true toads, and have features that are distinct from toads. They have vertical pupils similar to cats' eyes, hard black digging spades on their back feet, and smoother skin resembling that of a frog. Unlike a frog, however, they complete their egg-tadpole-adult cycle in just 3 weeks, allowing them to breed in temporary pools of water that form near Medano Creek each summer. Like tiger salamanders, they sometimes go into the dunes on rainy nights, then bury themselves in moist sand when the sun rises.
In mid-summer, Great Plains Toads (Bufo cognatus) are found in such large numbers near wetlands that it's actually hard to walk without stepping on one. They hop around looking for insects in grass, even on sunny days.
Woodhouse's toads (Bufo woodhousii) are the largest toad at Great Sand Dunes, sometimes growing over 4" (10cm) in length. They are occasionally seen on wet nights near the dunes parking area, but are more commonly found in somewhat remote wetlands west of the dunefield.
While most Woodhouse's toads in the park are a brown-grey color, a few individuals found in open, sandy habitats have a distinctive mottled sand-camouflage color. (Photo taken east of Cotton Lake, 2010, NPS/Patrick Myers).