This species exhibits many of the typical behaviors of anurans.They are nocturnal and rest during the day to avoid any predators, their venomous capacity not withstanding (Lutz 1971).They forage for food at night, typically preying on live insects such as caterpillars and earthworms (Lutz 1971).Males exhibit the ability to sing, which they use to attract females and to deter other males (Lutz 1971).
In 2004, this species was listed as endangered according to the IUCN Red List of Threatened Species (Santos-Barrera and Flores-Villela 2004). Their justification in this classification is due to the habitat size of the extant population, since Incilius cavifrons is an endemic species.The extent of the habitat range is less than 5,000 km2 and the area that it inhabits is less than 500 km2, qualifying it as an endangered species (Santos-Barrera and Flores-Villela 2004).
This species is endemic to the Sierra de Los Tuxtlas region of Mexico (Mendelson 1997).They are found on the slopes of the volcanoes San Martin and Santa Marta and have been found in lower elevations of the cities Zapoapan and Tebanca (Shannon and Werler 1955; Mendelson 1997).These areas are part of the largest tropical rainforest in Mexico (Cabrera-Guzman and Reynoso 2012).
The naming of the mountain toad was based on its morphology; cavus meaning hollow and frons meaning brow in Latin (Mendelson 1997). The combination of these Latin roots refers to the distinguishable hollowed presence at the top of the head that is formed by the hypertrophy of the cranial crests (Mendelson 1997).
The pine-oak forest located at the lower elevations of the San Martin and Santa Martin volcanoes is the habitat of I. cavifrons (Shannon and Werler 1955; Mendelson 1997; Santos-Barrera and Flores-Villela 2004).The volcanoes are found within the Humid Division of the Tropical Zone and are surrounded by the savannas of the Arid Division, creating boundaries that lead to this species’ endemism (Firschein 1950).The average annual temperature of this area is 22.2-25.6oC (72-78oF) with maximum temperatures reaching 33.3-36.7oC (92-98oF) and minimum temperatures dropping to 14.4-20oC (58-68oF) (Firschein 1950; Cabrera-Guzman and Reynoso 2012).Temperatures reach their lowest values due to the winds coming from the north in the winter months from December to February (Cabrera-Guzman and Reynoso 2012).The rainy season starts in late March and concludes in October, with the heaviest rains during June and September (Firschein 1950).Total rainfall during the dry season (January to May) is 2,500 mm; rainfall increases to 4,000 mm during the wet season (Cabrera-Guzman and Reynoso 2012).The amount of rainfall increases with the presence of tropical storms, which have the tendency to arise in September and October (Cabrera-Guzman and Reynoso 2012).
Incilius cavifrons, also known as Bufo cavifrons or commonly known as the mountain toad, is a naturally rare, endemic species.This species has a distinct color and morphological structure when compared to other toads found within the genus Bufo.This species is considered endangered under the IUCN Red List of Threatened Species and needs further protection under Mexican law.
The government has protected the area in which this species lives at the highest level of legislation (Durand and Lavos 2008).The area is protected under a reserve named the Los Tuxtlas Biosphere Reserve (Durand and Lavos 2008).The reserve incorporates the forest region of the San Martin (9,805 hectares) and the Santa Marta (18,301 hectares) volcanoes (CTC 2004).The management plan of the reserve is currently in progress, but it will incorporate the physical, biological and ecological aspects of the area (CTC 2004).
Bufo cavifrons is the largest species of the genus Bufo, ranging from 79.9 mm in males and 99.8 mm in females (Mendelson 1997).The males and females of this species have somewhat different body structures.The tympanum, an external hearing structure located behind the eye, is small in both male and females (Mendelson 1997).However, the diameter of the eye socket takes up 31-44% of the skull in males and 39-46% in females (Mendelson 1997).In comparison to other toad-like amphibians the preorbital crest and pretympanic crest is absent and the tibia is relatively short (Mendelson 1997).Also, the females have smaller feet (Mendelson 1997). Both males and females contain vocal slits, which are large and bilateral (Mendelson 1997).The interhyoideus muscle, which functions in swallowing, forms a small, unilobed unpigmented sac in both males and females (Mendelson 1997).The parotid glands, salivary glands, are relatively small and are typically triangular (Mendelson 1997).
The males and females have distinct color differences.The males are consistently yellow-brown with a dark brown scapular chevron and interorbital bar (Mendelson 1997).The femur, tibia and foot all contain a pale brown transverse bar (Mendelson 1997).On the dorsal surface, the keratinized tubercles are black (Mendelson 1997).The females contain a brown dorsal strip and a black line between parietal crests (Firschein 1950).The parotid gland has an apparent light gray appearance on the superior surface and is dark brown on the inferior surface (Firschein 1950).The tympanic area of the female is dark brown, with a black band above the jaw (Firschein 1950).Lastly, the upper surface of the femur is white in the female (Firschein 1950).Both the males and females have paler tips on the fingers compared to the rest of the body (Mendelson 1997). Males and females both contain a lateral row of tubercles, or round nodules on the skin.However, the tubercles found on females are widely spaced and not pointed like they are in males (Mendelson 1997).
In one study, opalinid protozoans were found in the intestinal tract, which is typical of most anuran amphibians of this area (Santos-Barrera 1994).Also, venom was found in the parotid gland of this species; this characteristic seems to be uniform across species in the genus Bufo (Porter and Porter 1967; Lutz 1971).
The breeding season is marked by the arrival of the spring season or the initiation of rainfall (Lutz 1971).This species breeds in and near springs at the heads of streams located at the bases of the San Martin and Santa Marta volcanoes (Mendelson 1997).Also, breeding has been discovered in temporary waters provided by summer rains (Korky and Webb 1973).The mating call of the males has been described as a low, soft trill (Shannon and Werler 1955).The males and females of this species have a distinct color difference of the interorbital bar while they are breeding.The female interorbital bar is markedly black while the males have a copper to a brownish-yellow color bar (Mendelson 1997).The females lay eggs separated by gelatinous strings (Shannon and Werler 1955; Lutz 1971). One of these strings was measured at 14.0208 meters long containing a total of 2,000 eggs, or 40-45 eggs per foot (Shannon and Werler 1955).
The dorsal portion of the larvae is black with a paler ventral discoloration (Korky and Webb 1973).The tail fin is clear on the ventral side and has speckled melanophores (black pigmented tissue that contains melanin) on the dorsal portion (Korky and Webb 1973). The mouth can be described as having complete mouthparts; the margins of the lips are infolded with the marginal papillae (Korky and Webb 1973).The larvae also have dorsal eyes (Korky and Webb 1973).
The Sierra de Los Tuxtlas region has lost nearly 84% of its original vegetation due to deforestation (Cabrera-Guzman and Reynoso 2012).Deforestation has created more than 1,005 fragments, which all differ in size and shape and have varying degrees of isolation (Cabrera-Guzman and Reynoso 2012).Areas below 900 m on the Santa Marta volcano were cleared for agriculture (Mendelson 1997).
A threat outside of human control to this species could be weather.Since this species lays their eggs in streams, they are vulnerable to the damage of tropical storms.Heavy rains and flooding can destroy the eggs before they are able to hatch (Shannon and Werler 1955).This could be part of the reason why this species has a rare and small population.
The mountain toad (Incilius cavifrons) is a species of toad in the family Bufonidae. It is endemic to the Sierra de los Tuxtlas region in southern Veracruz state, Mexico.[1][2]
Its natural habitats are tropical pine-oak forests. It breeds in streams.[1]
This naturally rare species is threatened by habitat loss caused by agricultural activities, wood extraction, and infrastructure development.[1]
The mountain toad (Incilius cavifrons) is a species of toad in the family Bufonidae. It is endemic to the Sierra de los Tuxtlas region in southern Veracruz state, Mexico.
Its natural habitats are tropical pine-oak forests. It breeds in streams.
This naturally rare species is threatened by habitat loss caused by agricultural activities, wood extraction, and infrastructure development.
