Adults. Males to 100 mm, females to 150 mm, occasionally up to 240 mm. Body is stout and heavy, often held in an upright posture. Back is grey, light brown, reddish-brown or yellow-brown with darker patches and spots (especially in females). Belly is white or yellowish, sometimes with grey mottling. Skin is dry, leathery, and warty (males often with more warts). Large parotoid (toxin secreting) glands on the shoulders, behind the obvious tympanum (eardrum). Distinct, firm ridges above eyes meet above the nose to form an ‘M’ shape. Pupil is horizontal and iris is gold. Fingers are unwebbed, toes are fully webbed, both without pads.

Metamorphs. 10-20 mm. Back is smooth and grey or black in colour, often with numerous small orange dots and white patches on the upper lip, below the eye. Parotoid glands are not yet visible, but the metamorphs are still toxic. They are often active during the day in huge numbers, possibly to avoid cannibalism by larger juveniles.⁷Juveniles. 20-90 mm. Highly variable in colour and pattern, but are starting to look and behave more like adults. The back begins to change in texture, showing more warts and bumps, and lightens in colour to show dark patches and spots and often a pale line down the spine. Belly is mottled grey and white. Many have a pair of dark spots on the head, forming a ‘V’ shape between the eyes. Parotoid glands become more noticeable and the bony ridges above eyes and on snout form. Juveniles are often found at night in large numbers near ponds, dams, or disturbed waterways.Larvae. Tadpoles are small, only reaching a length of 22-27 mm. Body is small, oval in shape and shiny black in colour on top. Belly is a plain and dark; most native tadpoles have pale or transparent bellies. Tail is slightly taller than the body, but is short and thin, arching only slightly and ending in a broadly rounded tip. Fins are mostly transparent, possibly with some fine dark flecks or blood vessels and muscle is black with a lighter bottom edge. Iris is black. Tadpoles often form dense schools at the bottom of ponds and stream pools. Thousands to millions of tiny metamorphs emerge en masse in summer and autumn, about a month after hatching.¹

Eggs. 7000-35,000 blackish eggs are laid in long, continuous strings of transparent jelly which are often wound around vegetation in shallow, still, or slow-moving water. Cane Toads are the only species in Australia to lay eggs in strings. Hatching usually occurs within two days of eggs being laid.¹

Habitat. Inhabits a wide variety of habitats ranging from sand dunes and coastal heath to the margins of rainforest, mangroves, and suburban gardens.

Artificial Pond

Tamborine Mountain, QLD

Natural Pond

Tamborine Mountain, QLD

Stream

Mount Glorious, QLD

Diet. Cane Toads are omnivorous and opportunistic, eating just about anything they can fit in their mouths; including small terrestrial arthropods (ants, beetles, termites, etc.), gastropods (snails and slugs), small vertebrates (frogs, reptiles, mammals, birds), rotting fruit, carrion, pet food, and each other.²

Predation & Defence. Known predators include crocodiles, snakes, turtles, birds, rodents, and invertebrates, like insects and crayfish.⁶

All life stages, from egg to adult, contain or secrete differing levels of bufodienolides, cardioactive steroids which can cause rapid heartbeat, excessive salivation, convulsions, and paralysis, and may result in death for some species.⁵ Tadpoles can produce alarm pheromones in response to disturbance or injury and even post-metamorphic toads respond to chemical cues, fleeing from injured cohorts.⁴

Call is a long, hollow-sounding, rolling, trilled ‘brrr’, like a small engine running. Able to breed year-round, but male choruses peak October-January.

Introduced to Australia in 1935

Least Concern where native in South, Central, and North America (IUCN Red List 2009)

Listed as Least Concern in view of its wide distribution, tolerance of a broad range of habitats, presumed large population, and because it is unlikely to be declining to qualify for listing in a more threatened category.⁸

Listed as a key threatening process (Environment Protection and Biodiversity Conservation Act 1999)

1. Anstis, M. (2017). Tadpoles and Frogs of Australia. Second Edition. New Holland Publishers, Sydney.
2. Cameron, E. (2020). Cane Toad. Australian Museum Animal Factsheets. https://australianmuseum.net.au/learn/animals/frogs/cane-toad accessed on Fri May 15.
3. Cogger, H.G. (2018). Reptiles and Amphibians of Australia. Updated 7th Edition. CSIRO Publishing, Melbourne.
4. Hagman, M. & Shine, R. (2008). Understanding the toad code: Behavioural responses of cane toad (Chaunus marinus) larvae and metamorphs to chemical cues. Austral Ecology 33: 37-44.
5. Hayes, R.A., Crossland, M.R., Hagman, M., Capon, R.J. & Shine, R. (2009). Ontogenetic variation in the chemical defenses of Cane Toads (Bufo marinus): Toxin profiles and effect on predators. Journal of Chemical Ecology 35: 391-399.
6. Markula, A., Csurhes, S. & Hannan-Jones, M. (2016). Invasive animal risk assessment: Cane Toad Bufo marinus. Biosecurity Queensland, Department of Agriculture and Fisheries.
7. Pizzatto, L., Child, T. & Shine, R. (2008). Why be diurnal? Shifts in activity time enable young cane toads to evade cannibalistic conspecifics. Behavioral Ecology 19(5): 990-997.
8. Solís, F., Ibáñez, R., Hamerson, G., Hedges, B., Diesmos, A., Matsui, M., Hero, J.-M., Richards, S., Coloma, L., Ron, S., La Marca, E., Hardy, J., Powell, R., Bolaños, F., Chaves, G. & Ponce, P. (2009). Rhinella marina. The IUCN Red List of Threatened Species 2009: e.T41065A10382424. https://dx.doi.org/10.2305/IUCN.UK.2009-2.RLTS.T41065A10382424.en. Downloaded on 25 April 2020.
9. Atlas of Living Australia occurrence download at https://doi.org/10.26197/5e9a2fc401f43 accessed on Sat Apr 18 08:37:47 AEST 2020.