The plains spadefoot toad (Spea bombifrons ) is a species of American spadefoot toad which ranges from southwestern Canada, throughout the Great Plains of the western United States, and into northern Mexico. Like other species of spadefoot toads, they get their name from a spade-like projections on their hind legs which allow them to dig into sandy soils. Their name, in part, comes from their keratinized metatarsals, which are wide instead of "sickle shaped". The species name translates as buzzing leaf shaped. This refers to the species distinguishing features; its buzzing mating call, and its leaf-shaped digging metatarsals. First described by Cope in 1863.
Nocturnality is an animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal",...
An insectivore is a carnivorous plant or animal that eats insects. An alternative term is entomophage, which also refers to the human practice of e...
A carnivore meaning 'meat eater' is an organism that derives its energy and nutrient requirements from a diet consisting mainly or exclusively of a...
An omnivore is an animal that has the ability to eat and survive on both plant and animal matter. Obtaining energy and nutrients from plant and ani...
Scavengers are animals that consume dead organisms that have died from causes other than predation or have been killed by other predators. While sc...
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TerrestrialTerrestrial animals are animals that live predominantly or entirely on land (e.g., cats, ants, snails), as compared with aquatic animals, which liv...
Oviparous animals are female animals that lay their eggs, with little or no other embryonic development within the mother. This is the reproductive...
Jumping (saltation) can be distinguished from running, galloping, and other gaits where the entire body is temporarily airborne by the relatively l...
A burrow is a hole or tunnel excavated into the ground by an animal to create a space suitable for habitation, temporary refuge, or as a byproduct ...
A territory is a sociographical area that which an animal consistently defends against the conspecific competition (or, occasionally, against anima...
A fossorial animal is one adapted to digging which lives primarily but not solely, underground. Some examples are badgers, naked mole-rats, clams, ...
Aestivation is a state of animal dormancy, similar to hibernation, although taking place in the summer rather than the winter. Aestivation is chara...
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starts withThe plains spadefoot toad generally grows from 1.5 to 2.5 inches (38 to 64 mm) in length, has a round body, with relatively short legs. These toads are usually a tannish to dark brownish color with visible orange spots. They are one of the easiest toads to recognize in their region because of their appearance looking more like a frog. Sometimes, they have light striping on their backs.
Frogs in general, but fossorial frogs specifically are able to absorb water through a "seat patch" instead of drinking. The skin is selectively permeable via aquaporins, allowing them to absorb water from damp ground, standing water, and mossy substrates.
According to David Pfenning's lab at the University of North Carolina, Desert spadefoots appear able to not only adapt their bodies to a carnivorous diet (Shorter gut, protein-digesting genes are activated) but also are more likely to have progeny that are adapted to meat. This is a major study that shows that Lamarckian characteristics are not as disproven as once thought.
Both Spea species found in North America have been used for many years in the North Carolina lab of Karin Pfennig as model organisms to study hybridization and its effects on competition and evolution. The results appear to be mixed, but there is evidence of resource competition being linked to species divergence.
Plains spadefoot toads are nocturnal and secretive. They spend most of the dryer seasons buried in the soil in estivation, typically only emerging during spring and fall rains. Breeding takes place in temporary pools of water left by rainfall, which requires the tadpoles to metamorphose quickly, before the water dries up. Eggs, laid in clutches numbering from 10 to 250, often hatch within 48 hours of being laid, and the larvae can change into tadpoles in as little as two weeks. The tadpoles exhibit phenotypic plasticity, with some changing from an omnivorous morphology into a cannibalistic carnivorous morph with oversized jaw muscles and pronged beaks. In some cases, female spadefoot toads will choose to mate with Spea multiplicata rather than with males of their own species, if the resulting hybrid tadpole would have higher chances of survival. Character displacement has also been examined in ponds where Spea bombifrons and Spea multiplicata occur together. Reproductive and ecological competition between the two species likely causes selection for smaller and less reproductively successful individuals of Spea multiplicata.
The adults travel by short hops and are generally poor swimmers. They swim in short bursts and only during periods of reproduction. this species is presumed to be non territorial and solitary except during breeding season. Satellite males have been shown to attempt to intercept females arriving at a breeding pond and are successful in about 20% of cases. Dominant, or first arriving males signal vocally from the deepest part of the ephemeral pool. Amplexus is a necessary stimulus to release eggs. Once the eggs are fertilized, there is little apparent parental care. The adults are strictly live insectivores. The tadpoles are detritivores, either scavengers or herbivores depending on morph
Tadpole "nests" can bee seen in most xeric amphibians, and are well described in the fossil record, such as at the St. George Dinosaur Discovery site. The shallow depressions are a form of "vortex feeding" used to stir up debris for feeding. It is also theorized that the depressions formed could allow a lengthened hydroperiod to increase growth size.