The Great Basin Spadefoot (Spea intermontana) is a species of toad

Toad

A toad is any of a number of species of amphibians in the order Anura characterized by dry, leathery skin , short legs, and snoat-like parotoid glands...

 in the Scaphiopodidae family.

Identification

The Great Basin Spadefoot ranges from 3.8 to 6.3 cm long. It is usually gray, olive, or brown colored. Gray streaks outline an hourglass shaped marking on the back. The skin is smooth compared with the bumpy skin of the true toads in the genus Bufo. There is a spade present on the inside of each hind foot; it has sharp edges and is wedge-shaped. A glandular boss is present between the eyes. Eyes are catlike; pupils are vertical in bright light and round at night. Dark brown spots are present on each upper eyelid.

Habitat and Distribution

The natural habitat

Habitat

* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...

s of the Great Basin Spadefoot include pinyon-juniper, ponderosa pine

Ponderosa Pine

Pinus ponderosa, commonly known as the Ponderosa Pine, Bull Pine, Blackjack Pine, or Western Yellow Pine, is a widespread and variable pine native to western North America. It was first described by David Douglas in 1826, from eastern Washington near present-day Spokane...

, and high elevation spruce-fir forests, semidesert shrubland

Shrubland

Shrubland, scrubland, scrub or brush is a plant community characterized by vegetation dominated by shrubs, often also including grasses, herbs, and geophytes. Shrubland may either occur naturally or be the result of human activity...

, sagebrush

Sagebrush (plant)

Sagebrush is the common name for Artemisia tridentata and a number of other species of shrubby plants in the genus Artemisia, native to the North American west and other parts of the world. It is sometimes confused with sage plants ....

 flats, temperate grasslands, and deserts

Déserts

Déserts is a piece by Edgard Varèse for brass , percussion , piano, and tape. Percussion instruments are exploited for their resonant potential, rather than used solely as accompaniment...

. They are present in agricultural areas as well. The Great Basin Spadefoot can be found from southern British Columbia through the eastern portions of Washington and Oregon and in southern Idaho. Their range extends throughout all of Nevada and into most of Utah; they are also present in small areas in California, Arizona, Colorado, and Wyoming.

Reproduction

Breeding is explosive, meaning that large congregations of individuals assemble and mate with each other. Adults are terrestrial and must migrate to breeding sites. Breeding may take place in permanent or temporary water sources such as springs, sluggish streams, and manmade reservoirs during the months of April through July. Males call and attract females to breeding sites. Once females arrive, there is a race to mate with as many others as possible, and physical contests between males are common. Females usually lay 300-500 eggs, but have been reported lay as many as 1000 eggs in captivity. Eggs are attached to vegetation present in the water or placed at the bottom of the pool. Eggs hatch in 2 to 4 days, and the larval period lasts an average of 36 days. Tadpoles may be carnivorous or herbivorous, depending on environmental conditions. Different larval diets are associated with different morphological characteristics.

Diet

Adults have been shown to eat arthropods from the taxa Coleoptera, Diptera

Diptera

Diptera , or true flies, is the order of insects possessing only a single pair of wings on the mesothorax; the metathorax bears a pair of drumstick like structures called the halteres, the remnants of the hind wings. It is a large order, containing an estimated 240,000 species, although under half...

, Hemiptera

Hemiptera

Hemiptera is an order of insects most often known as the true bugs , comprising around 50,000–80,000 species of cicadas, aphids, planthoppers, leafhoppers, shield bugs, and others...

, Hymenoptera

Hymenoptera

Hymenoptera is one of the largest orders of insects, comprising the sawflies, wasps, bees and ants. There are over 130,000 recognized species, with many more remaining to be described. The name refers to the heavy wings of the insects, and is derived from the Ancient Greek ὑμήν : membrane and...

, Lepidoptera

Lepidoptera

Lepidoptera is a large order of insects that includes moths and butterflies . It is one of the most widespread and widely recognizable insect orders in the world, encompassing moths and the three superfamilies of butterflies, skipper butterflies, and moth-butterflies...

, Neuroptera

Neuroptera

The insect order Neuroptera, or net-winged insects, includes the lacewings, mantidflies, antlions, and their relatives. The order contains some 6,010 species...

, Orthoptera

Orthoptera

Orthoptera is an order of insects with paurometabolous or incomplete metamorphosis, including the grasshoppers, crickets and locusts.Many insects in this order produce sound by rubbing their wings against each other or their legs, the wings or legs containing rows of corrugated bumps...

, Trichoptera

Trichoptera

The caddisflies are an order, Trichoptera, of insects with approximately 12,000 described species. Also called sedge-flies or rail-flies, they are small moth-like insects having two pairs of hairy membranous wings...

, Collembola, and Araneae. Ants and beetles are their most common prey. Feeding seems to be generalized and opportunistic; the toads will eat anything they can subdue.

Defense Mechanisms

Reported predators of adult Great Basin Spadefoot toads include rattlesnakes, coyotes, and owls. Predators of larva include crows, trout, and garter snakes. Adults are able to produce skin secretions that cause allergic reactions in some humans, including a burning sensation if the secretion gets in the eyes or nose. Some researchers believe the skin secretions deter predators.

Burrowing Behavior

Great Basin Spadefoot toads have adapted to life in dry habitats. Desiccation is avoided by this terrestrial amphibian through burrowing into the ground. The Great Basin Spadefoot uses the hard, keratinized spade on each foot to dig a burrow, where it spends long periods during cold and dry weather. The toad is able to absorb water from the surrounding soil; even as the soil becomes increasingly dry in spring and early summer months, increased concentrations of urea in the toad's body allow it to continue to suck water out of the soil through osmosis. When the summer rains arrive the Great Basin Spadefoot is able to emerge from its burrow.

External links

• Great Basin rangemap - IUCN