Toads are a group of frogs. In that, the difference between a family of frogs and toads is no more different than the differences between two families of frogs. Toads and frogs have a common ancestor and are grouped under the order Anura, meaning those that lack a tail. However, several distinguishing characters do help differentiate toads from frogs. One of the most common factors is their dry, warty skin. Many species of toads have specialised poison glands called parotoid glands, located behind the eyes, which produce a toxin unique to toads called bufotoxin. Emerging research indicates that this toxin is extremely potent. Toads are generally adapted to drier habitats and many species are found away from water, including under fallen logs in a forest or in between potted plants of your garden.
The diverse landscape of Karnataka harbours at least eight species of toads, belonging to three genera. Although widespread and relatively common, very little is known about these toads, especially those that live in the forests of the Western Ghats or among the rocky boulders found across Karnataka. Here is a glimpse of this fascinating group of frogs that we call toads.
Common Toad (Duttaphrynus melanostictus)
The Common Toad is one of the most widespread species of anurans that is distributed across India as well as parts of Southeast Asia. Individuals are variable in size with females sometimes being as large as one’s palm. The males and females are typically brown with mottling and in the breeding season, the males turn bright yellow. They congregate near water bodies and males produce loud vocalisations. They scramble to mate with a female and lay a string of eggs which hatch into baby toadlets which can be seen hopping about after the rains in ponds, fountains, temple tanks (locally known as kalyani), as well as larger water bodies such as irrigation tanks and rivers.
The species, along with 25 others including those from SE Asia were recently moved from the genus ‘Bufo’ to ‘Duttaphrynus’, an honorific genus named after an Indian Batrachologist, Retd. Prof. Sushil Kumar Dutta.
Günther’s Toad (Duttaphrynus hololius)
One of the few amphibians encountered in rocky habitats, this small toad doesn’t have prominent parotoid glands. It is likely to be found all along the rocky habitats of peninsular India but very little is known about it. In the last five to ten years, people have begun to document this species through careful comparisons with museum specimens and have gone on to document the natural history of this species. Overall, the toads are reddish-brown, often interspersed with mottled patches of ivory with bright red spots. Toes and fingers are whitish, and the tympanum is visible. Being restricted to rocky areas, their population is threatened by quarrying and habitat degradation.
Schneider’s Dwarf Toad (Duttaphrynus scaber)
One of the smaller sized anurans we encounter across much of Karnataka is the dwarf toad. The term dwarfs may be misleading as the toad is nearly the length of a human thumb. They are of slender build and the poison glands are weak. The dorsal colour is whitish brown with white stripes. The males vocalise from vegetation floating on water and have a prominently yellow vocal sac. They breed in stagnant or slow-flowing water. The species is currently known to occur across peninsular India as well as parts of Sri Lanka.
Kempholey Toad (Duttaphrynus brevirostris)
This enigmatic toad was described from the forests of Kempholey in 1937 by Prof. Coimbatore Narayana Rao of the Central College. The short description was based on a single specimen and subsequently, the specimen was lost, resulting in a lot of confusion about the species identity. Just last year, researchers have clarified that this species is a valid species and provided first-ever colour photographs as well as molecular data of this species, which has so far been reported from the Western Ghats of Karnataka. The toad is golden yellow and lacks prominent ridges on the head. Being closely related to the Common Toad, the two species may be confusing to identify in the field without acoustic comparisons which, so far, appears to be undocumented.
Peninsular Toad (Duttaphrynus peninsularis)
The Peninsular Toad was described as a variety of Duttaphrynus stomaticus in 1920 by C.R. Rao from Coorg. As in the case of the Kempholey Toad, the specimens were lost and, in the meantime, researchers considered the sub-species D. stomaticus peninsularis as a mere variety of D. stomaticus and considered it as a synonym of D. stomaticis. This resulted in widespread confusion and misreporting as otherwise, D. stomaticus is known only from parts of North India. In the year 2021, researchers clarified the status of D. stomaticus peninsularis, removed it from synonymy and erected the species Duttaphrynus peninsularis based on new specimens and molecular comparisons. The Peninsular Toad is yellow with marbling on the dorsum, interspersed with black spots. This species is currently known from Karnataka, Tamil Nadu, and Maharashtra.
Malabar Torrent Toad (Ghatophryne ornata)
The torrent toad is unique in the sense that they are found in and around torrential streams in parts of the Western Ghats. Slender bodied and overall dark black, the toads are active at night and can be heard vocalising from between rocks in torrential streams. Prominent spinular projections are easily observed on the body. The fingers and toes are unwebbed, but the toads are adept at climbing up crevices as well as hollow tree trunks along the streamside. Until the year 2009, the two species of torrent toads, Ghatophryne rubra and Ghatophryne ornata were removed from the genus Ansonia, which now comprises species from SE Asia based on genetic differences. They were placed in a genus called Ghatophryne, which is a combination of Sanskrit (Ghat meaning steps, referring to the Western Ghats) and Greek (Phryne, referring to toads). Both species in this genus are endemic to the Western Ghats. Read more about this toad here.
Malabar Tree Toad (Pedostibes tuberculosus)
This is an enigmatic species of toad that is endemic to the Western Ghats. Until about 2006, the frog was extremely rare with only a handful of sightings. People subsequently began reporting sights of these frogs from the forests of Karnataka and it appeared that they were more common than it was thought to be. It turned out that the frogs were locally abundant where they were found. Moreover, they are arboreal and live in the treetops for most parts of their life. They breed in phytotelmata, waterfilled cavities in the trees, and hardly ever descend to the ground. Thanks to an initiative called Mapping Malabar Tree Toad, using the citizen science forum India Biodiversity Portal, there are currently 194 records of this species reported by 95 observers. This brown frog is vocal early in April, before the monsoon and usually goes silent with the onset of heavy rains. They descend low into the shrubs where they congregate in groups of over 20 individuals and lay eggs in water-filled cavities such as tree holes. Little else is known about these frogs. Given how common they are in Karnataka, there is a proposal to name this species as the State Frog of Karnataka.