Ceratophrys cornuta

Amazon horned frogs, Ceratophrys cornuta, are found in the Amazonian Basin of Colombia, Ecuador, the Guianas, Venezuela, Peru, Bolivia, and Brazil (IUCN, Conservation International, and NatureServe, 2004). ("Global Amphibian Assessment", 2004)

Amazon horned frogs occur in open areas within the forest (IUCN, Conservation International, and NatureServe, 2004). They are found within the leaves on the forest floor (Project Amazonas Inc., 2003). Horned frogs are terrestrial and reside near freshwater marshes and pools within old forest areas (IUCN, Conservation International, and NatureServe, 2004). ("Global Amphibian Assessment", 2004; "Project Amazonas Inc.", 2003)

These frogs are fairly large, ranging from 7 to 15 centimeters in length (Staniszewski, 1995). The body is very round and the head is prominent (Project Amazonas Inc., 2003). Color of males can range from tan or lime to dark green. Sometimes, males display all of these colors simultaneously, whereas females are usually just tan (Bartlett and Bartlett, 2003). The ventral surface of these frogs is gray (Staniszewski, 1995; Duellman, 1978). The limbs are short and exhibit dark bands of coloring (Bartlett and Bartlett, 2003; Duellman, 1978). The thighs are colored brown with faint yellow spotting (Duellman, 1978). The body exhibits small pointed warts, and the mouth is white (Staniszewski, 1995). Females of this species are larger, and the males have nuptial pads on the toes of the front feet (Staniszewski, 1995). The most distinguishing feature of this species is the presence of horns above the eyes (Bartlett and Bartlett, 2003; Duellman, 1978; Staniszewski, 1995). (Bartlett and Bartlett, 2003; Duellman, 1978; "Project Amazonas Inc.", 2003; Staniszewski, 1995)

After fertilization, the eggs take anywhere from 3 to 25 days to hatch (Huitt, 2003). Once the tadpoles hatch from their eggs, they take about 90 days to metamorphose (Staniszewski, 1995). After metamorphosis, the tiny frogs are from 1 to 1.3 centimeters in length (Staniszewski, 1995). (Huitt, 2003; Staniszewski, 1995)

Mating is started when the males call to the females, and once two are paired the eggs are put onto the back of the female by the male. Mating appears to be polygynous. (Huitt, 2003) (Huitt, 2003)

Amazon horned frogs mate seasonally (Zug, Vitt, and Caldwell, 2001). They reach sexual maturity at around 3 to 4 years of age (Staniszewski, 1995). These frogs mate in ephemeral pools and, compared to the size of the adults, the number of eggs they deposit is very minimal at about 300 to 600 eggs (Bartlett and Bartlett, 2003). Mating is initiated when the males call to females. Once two are paired, the eggs are put onto the back of the female by the male (Huitt, 2003). Finding an appropriate place for the offspring to develop is the duty of the female, and hatching occurs sometime between 3 and 25 days after fertilization (Huitt, 2003). (Bartlett and Bartlett, 2003; Huitt, 2003; Staniszewski, 1995; Zug, et al., 2001)

The main forms of parental care provided in this species are provided by the female. In addition to supplying eggs with an adequate food supply for development of the young, the mother frog selects a safe place to deposit her eggs after they have been fertilized. After depositing the eggs in a safe location, male and female Amazon horned frogs have no parental involvement with their offspring. There is high mortality in the young, so that although many eggs are laid, not many offspring survive.

Little is know about the lifespan of C. cornuta in the wild, but in captivity they have fairly long lives. Captive individuals reach an average age of 10 years (Max-Planck-Gesellschaft, 2005). A maximum lifespan of 15 years has been recorded in captivity (Staniszewski, 1995). ("Longevity Records", 2005; Staniszewski, 1995)

Ceratophrys cornuta is nocturnal, coming out only at night in order to avoid the excessive warmth of the day (Huitt, 2003). A notable behavior of these frogs is the way that they capture prey. Horned frogs bury themselves in the leaves on the ground with only the head sticking out. Hidden in this manner, an individual waits for something edible to pass by--at whcih time it strikes (IUCN, Conservation International, and NatureServe, 2004).

These frogs can be violent when fully grown (Staniszewski, 1995). They are solitary, and a male will defend his territory violently (Huitt, 2003). (Huitt, 2003; "Global Amphibian Assessment", 2004; Staniszewski, 1995)

The size of the home range of these frogs is not known.

When trying to find a potential mate, communication is mostly acoustic. When males are together in a group, they exhibit a noisy bleating sound (Bartlett and Bartlett, 2003). During mating itself, some tactile communication is undoubtedly important.

When feeding, these frogs bury themselves in the substrate and wait for the motion of passing prey (Bartlett and Bartlett, 2003; IUCN, Conservation International, and NatureServe, 2004). In this instance, their main mode of perception is visual. (Bartlett and Bartlett, 2003; "Global Amphibian Assessment", 2004)

Amazon horned frogs are ravenous predators, having large mouths and long teeth to help them eat prey (Zug, Vitt, and Caldwell, 2001). They are considered "wait-and-ambush" hunters because they bury themselves in the substrate with only their faces outside the ground (Bartlett and Bartlett, 2003; IUCN, Conservation International, and NatureServe, 2004). Once in this position, C. cornuta eats almost anything that passes, as long as it will fit in the frog's mouth (Project Amazonas Inc., 2003). They have been known to feed on mice, fish, and tadpoles of their own species (Huitt, 2003). They also eat other smaller frogs (Huitt, 2003; Project Amazonas Inc., 2003). (Bartlett and Bartlett, 2003; Huitt, 2003; "Global Amphibian Assessment", 2004; "Project Amazonas Inc.", 2003; Zug, et al., 2001)

The cryptic coloration of these frogs is thought to be an anti-predator adaptation as it aids in camouflaging them in their surroundings (Huitt, 2003; Project Amazonas Inc., 2003). It is also thought that the horns may function as part of this camouflage, since the horns may be perceived by predators as the stem of a leaf or other such object (Project Amazonas Inc., 2003). (Huitt, 2003; "Project Amazonas Inc.", 2003)

Ceratophrys cornuta preys upon many small animals, such as rodents and frogs, and serves as prey for larger animals. Beyond these relationships, little is known about the role of these frogs in their ecosystem.

One benefit of this species for humans is its availability in the pet trade. Their strange look and their violent appetites make them favorable pets for herpetologists (Project Amazonas Inc., 2003). ("Project Amazonas Inc.", 2003)

These frogs do not actively seek to harm humans, but they do have very sharp teeth and can bite hard if not handled carefully (Bartlett and Bartlett, 2003). (Bartlett and Bartlett, 2003)

Althought C. cornuta is listed as least concern by the IUCN Red List, actions of humans may still have adverse affects on this species. Population numbers may be affected through the pet trade, since the majority of those sold are being taken directly from the wild (IUCN, Conservation International, and NatureServe, 2004; Project Amazonas Inc., 2003). Drops in population numbers may be avoided by stopping the collection of this species from the wild and making only captive-bred specimens available as pets. ("Global Amphibian Assessment", 2004; "Project Amazonas Inc.", 2003)