Oak toads are generally found in moist, grassy areas near pine or oak savannahs with sandy soil. They are also found in vernal pools and freshwater wetlands. They breed in shallow pools, ditches, and ponds.
Habitat Regions: temperate ; terrestrial ; freshwater
Terrestrial Biomes: savanna or grassland ; forest
Aquatic Biomes: lakes and ponds; rivers and streams; temporary pools
Wetlands: marsh
The primary predators of oak toads are snakes, particularly hognosed snakes (Heterodon platirhinos), specialized for eating toads. Other predators of oak toads are garter snakes (Thamnophis sirtalis) and gopher frogs (Lithobates capito).
Known Predators:
Anti-predator Adaptations: cryptic
Anaxyrus quercicus is the smallest toad species in North America, ranging from 1.9 to 3.3 cm. It is so small that adults found in the wild were commonly classified as “half-grown” or “juvenile” southern toads (Bufo lentiginosus). They have a short head with a pointed nose and the short, flat body is black or brown in color (color can change with temperature) with a long dorsal stripe that may be white, cream, yellow, or orange. There are 4 to 5 pairs of dark blotches found on the back. The back is finely tuberculate, with the fine bumps (red, orange or reddish-brown in color) giving it a rough texture. The underside is grayish white and has no blotches, but is covered in tubercles. Oak toads have elongated, teardrop-shaped paratoid glands that extend down either side. These glands house a poisonous fluid used deter predators. Males can be distinguished by their dark, dusky colored throats.
Range length: 19 to 33 mm.
Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry ; poisonous
Sexual Dimorphism: female larger; sexes shaped differently
Oak toad lifespans are not well known.
Average lifespan
Status: captivity: 1.9 years.
Male oak toads make a high-pitched, bird-like chirping calls to attract females. Oak toads perceive their environment through visual, auditory, tactile, and chemical senses.
Communication Channels: acoustic
Other Communication Modes: choruses
Perception Channels: visual ; tactile ; acoustic ; chemical
Oak toads are found in the coastal plains of the southeastern United States. They are found from the southern tip of Florida to the southern portion of Virginia and to parts of eastern Louisiana.
Biogeographic Regions: nearctic (Native )
Oak toads are predaceous and feed primarily on terrestrial insects and other small arthropods.
Animal Foods: insects; terrestrial non-insect arthropods
Primary Diet: carnivore (Insectivore , Eats non-insect arthropods)
Although smaller than other toads, the Oak Toad still plays a crucial role in insect population control.
Oak toads help control population levels of insects and other small arthropods.
Positive Impacts: controls pest population
There are no known negative impacts of oak toads on humans.
In the span of two months, tadpoles hatch from their eggs and go through metamorphosis, becoming adult toads. Tadpoles have a grayish olive or grape green color to the body due to close set dots against a black background. The underside has a pale purplish color. the tail has 6-7 black saddles (coloration that wraps around the tail to a degree). Juvenile toads remain near the natal pond for a few days before moving to land, where they will spend the majority of their time.
Development - Life Cycle: metamorphosis
Oak toad populations are declining throughout many states. In Virginia it is listed as a species of special concern (one that is not yet threatened but is expected to be in the near future). Also, in North Carolina, it is on the watch list for species that may be facing problems in the near future. A possible cause for decreases in oak toad populations is the clearing of the savannah forest habitats they prefer.
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: least concern
Males arrive before females at shallow, semi-permanent or temporary ponds, and roadside drainage ditches. At breeding ponds males establish territories and begin calling females with a high-pitched chirp. Approximately 100-250 eggs are laid at a time in long strings, held together by a gelatinous material, and either float or stick to surfaces. Fertilization takes place externally when the male frog releases his sperm in the vicinity of the eggs. In the case of a testicular malfunction, male oak toads have an ovary that will become functional, allowing them to breed as females.
Mating System: polygynandrous (promiscuous)
Male and female oak toads form a pair when the male grabs onto the female from behind in a position referred to as amplexus. The male stays attached to the female until she releases her eggs into the water. The female emits several eggs and then the male releases sperm into the water. The female will continue to release eggs. The eggs are released in bars containing 4-6 eggs apiece. Each female will lay about 700 eggs in total in a single season. These eggs will hatch within 3 to 3.5 days and develop into adult oak toads within 2 months.
Breeding interval: Oak toads are seasonal breeders and breeds once per year.
Breeding season: Oak toads breed from April to September or October. The mating season often begins with the arrival of warmer temperatures and thunderstorms. The interval of ovulation is approximately late May-mid August.
Average number of offspring: 700.
Range time to hatching: 72 to 80 hours.
Average age at sexual or reproductive maturity (female): 2 months.
Average age at sexual or reproductive maturity (male): 2 months.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (External ); oviparous
The extent of female energy investment is great during the ovulation and mating periods, as many females are found dead during these periods due to either the rigors of pair formation or energy investment in the laying of eggs. Once the eggs are fertilized and attached to a surface, there is no further parental care.
Parental Investment: no parental involvement; pre-fertilization (Provisioning)
The oak toad (Anaxyrus quercicus) is a species of toad in the family Bufonidae. It is endemic to the coastal regions of southeastern United States.[2][3] It is regarded as the smallest species of toad in North America, with a length of 19 to 33 mm (0.75 to 1.30 in).[3]
The oak toad can be identified by its light mid-dorsal stripe, variable brown and black spots, and proportionally large parotoid glands. One of the most remarkable features of this species is its small adult size relative to other toads.
The male can be distinguished from the female by his clear white belly and a slightly distended, loose flap of skin beneath the mouth, which expands into the vocal sac. The female has a dark-spotted belly and lacks a vocal sac.
The oak toad is native to the coastal regions of the southeastern United States, ranging from eastern Louisiana to southeast Virginia and south throughout Florida. It is found in a variety of habitats, including sandy pine flatwoods and oak scrub, open pine and pine-oak woods, pine or oak savanna with sandy soils, and maritime forests. Oak toads prefer open-canopied pine flatwoods with grassy ground cover, and they are generally found in moist, grassy areas near pine or oak savannahs with sandy soil. They are also found in vernal pools and freshwater wetlands.[1][4] [5]
It is mostly diurnal and spends much of its time burrowed into the loose soil of its habitat. It may remain in its burrow during the winter, often in hibernation.[6] Breeding takes place in shallow pools that accumulate during heavy rains. The male expands his distinctive elongated vocal sac to produce a chirping call. The breeding season extends from April to October, peaking early on.[7][8] Heavy, warm spring rains stimulate mating behavior.[9]
An average of 300 to 500 eggs are laid in short strands of 3 to 8 eggs each, with each egg about a millimeter wide.[6] The strands are attached to vegetation, usually submerged blades of grass 4 to 12 cm (1.6 to 4.7 in) beneath the surface.[10][11] Energy investment in producing this quantity of eggs is significant, and many females are found dead during the mating season due to the rigors of the process. Fertilization takes place externally, with sperm being released in the vicinity of the eggs. As with other species of toad, the male oak toad has a Bidder's organ, which can become a functional ovary in the event of testicular malfunction.[12][13]
The oak toad is a small, terrestrial frog that feeds on a variety of insects and other small invertebrates. Its diet consists primarily of ants, beetles, and spiders, as well as other insects and arthropods. The oak toad spends much of its time foraging for food, using its long, sticky tongue to capture prey. The oak toad eats mainly small insects and other arthropods. The adult has a strong preference for ants.[6]
Eggs develop quickly, hatching in a mere 24 to 36 hours.[6] The tadpole reaches a maximum length of 18 to 19.4 mm (0.71 to 0.76 in). It is grayish olive or grape-green dorsally and purplish ventrally. The tail has 6 or 7 black saddle marks.[12][13] The tadpole completes metamorphosis into a juvenile toadlet in 4 to 6 weeks, and it reaches adulthood and sexual maturity at 1.5 to 2.3 years of age.[6] The length of the lifespan is unclear.[3] There are records of specimens living for four years in captivity,[10][12] and the reported average lifespan in captivity is 1.9 years.[14]
The primary predators of the oak toad are snakes, particularly hognosed snakes, which are specialized for eating toads. Other predators include garter snakes and gopher frogs.[12][15] As with many bufonids, the oak toad inflates its body in unkenreflex when confronted by a potential predator. It secretes toxins from its parotoid glands and urinates when threatened. The male may chirp as a response to predators. Eggs also appear to have some toxic properties.[6]
The oak toad is listed as "least concern" by the International Union for Conservation of Nature.[1] It can become rare locally due to habitat replacement by loblolly pine plantations, urbanization and draining of surface water in its preferred wooded habitats.[1]
The oak toad (Anaxyrus quercicus) is a species of toad in the family Bufonidae. It is endemic to the coastal regions of southeastern United States. It is regarded as the smallest species of toad in North America, with a length of 19 to 33 mm (0.75 to 1.30 in).