The cane toad (Rhinella marina) or giant toad is native to south and central America. It has been introduced to many countries, including northern and eastern Australia. The cane toad is a declared pest under the Biosecurity and Agriculture Management Act 2007 (BAM Act) in Western Australia (WA).
The Western Australian Organism List (WAOL) contains information on the area(s) in which this pest is declared and the control and keeping categories to which it has been assigned in WA. Use the links on this page to reach cane toad in WAOL.
Identification and behaviour
Cane toads are the only true toads present in Australia. They are heavily-built and are typically 100–150mm in length. They can grow to more than 230mm and over 1kg in weight, but in areas with high toad densities individuals rarely exceed 100mm in length. The skin of cane toads is dry and rough rather than moist and slippery like many native frogs.
The backs of male toads have large warty lumps that feel like sandpaper when rubbed, while females have slightly smoother skin with less prominent lumps. The body colour on top ranges from dull brown to yellowish or blackish (never bright greens, yellows or reds) and there is rarely any marked pattern. The light underparts are usually mottled with brown.
The large glands behind the head can sometimes exude a poisonous milky substance when the toads are disturbed. Other distinctive features include a visible eardrum, bony ridges on the head, slight webbing between the toes (but not the fingers) and lack of enlarged pads (suckers) on the digits.
The call of the male is a guttural trill, sustained for about 30 seconds, and very different from most native frog calls.
Cane toads are most active at night, often in open areas such as roads and lawns. They sometimes congregate beneath streetlights and other lights to catch insects. On land, toads walk and hop short distances, but do not leap or climb smooth surfaces like some native frogs. They also typically sit more upright than many native frogs. Where toads have established in the wild they can occur in much larger numbers than native frogs.
The egg masses (spawn) of cane toads are unlike those of most native frogs and the tadpoles are also different. Toads produce chains of black eggs about 1mm in diameter enclosed in a thick transparent gelatinous cover, forming long strands about 3mm thick.
Toad tadpoles are jet black and reach a maximum of about 30mm from head to tail. They have non-transparent abdominal skin, their bodies are wider than they are long and their tails are relatively short with a dark central muscle and clear fins. The tadpoles of native frogs are generally very dark (but not jet black) with lighter or transparent abdominal skin and longer tails. Toad tadpoles form large slow-moving groups at the water’s edge and do not rise often to the surface to ‘breathe’. In contrast, tadpoles of native frogs regularly rise to the surface, having developed lungs sooner.
Newly-formed toads (metamorphs) are small (9-11mm) compared to adults and are conspicuous by their large numbers and daytime activity near their watery breeding sites. They develop into juveniles that have a distinct camouflage pattern that diminishes with age.
For further information, or to report a cane toad sighting, please contact the Cane Toad Hotline 1800 44 WILD (1800 449 453), or the Department of Parks and Wildlife.
Cane toads mostly eat insects, but will consume whatever else they can fit into their mouth including spiders, snails, small frogs, other cane toads, reptiles and mammals. Unlike native frogs, toads also eat inanimate items including pet food, cigarette butts and animal excreta.
Distribution and habitat
The natural range of the cane toad includes Brazil, through central America to eastern Mexico and Texas. Feral populations now occur in many countries including other parts of the Americas and many island groups. Toads were introduced into Puerto Rico, Hawaii and the Philippines in the 1920s and 1930s, and to Queensland in 1935 to control insect pests of sugar cane, but there is no evidence that this was effective.
Since their introduction to Australia, toads have proved to be highly invasive and computer modelling indicates that they could spread over most coastal areas of the continent. They are still spreading in eastern and northern Australia, including two off-shore islands in the Northern Territory. They are also spreading west and now occur in the Kimberley district of WA.
Reproduction and longevity
In Australia, cane toads normally breed from June to January although breeding may occur throughout the year. Females produce 8 000-35 000 eggs at a time and can breed at least twice a year. Local conditions greatly influence the number of eggs and tadpoles that survive to become adults. Toads normally lay eggs in slow-moving freshwater streams or dams, but can also use brackish water and temporary pools and puddles. Tadpoles hatch in 48-72 hours and, depending on temperature and food, they can develop into metamorphs in 17-180 days, reaching sexual maturity in approximately 18 months. Toads can live for at least 15 years in captivity and individuals have bred for at least five years in the wild.
Native animals affected by cane toads in Australia include frogs, reptiles such as large goannas, crocodiles and blue tongue lizards, fish and mammals such as quolls (native cats). They are vulnerable to cane toad toxin (all toad life stages are poisonous) and are often killed when cane toads first arrive in an area, leading to population reductions. Toads also compete with native species for food, consuming large numbers of native invertebrates, and they carry diseases that can spread to native frogs. Although there are some reports of native predators consuming cane toads safely, the longer-term impact of cane toads on native fauna is not yet clear and is the subject of ongoing research.
Toads eat beneficial insects like dung beetles and constitute an economic threat to beekeepers. Cane toad poison is highly toxic to most animals and causes pain if it comes in contact with eyes. Without emergency veterinary care, dogs and cats which mouth or bite cane toads sometimes die.
Biological control may be the only long-term means of reducing the number of cane toads across large areas. Research to date has been unable to find a suitable disease or parasite specific to cane toads that will provide effective control.
Various physical methods for reducing toad numbers including traps, hand removal and fences are being used by government and volunteer groups in an attempt to slow the westward movement of toads. The effectiveness of these techniques is still being investigated.
Anything being moved from toad-infested areas outside or within WA could contain cane toads and this has already occurred. Vigilance is required by freight companies and travellers as toads have been found in pipes, containers and fruit packaging as well as pot plants, shoes and camping gear. Until effective control methods are available, quarantine checks, public awareness and the removal of detected toads will reduce their rate of spread.
Native frogs sometimes mistaken for cane toads
Western Australia has 78 species of native frogs. The photographs below, arranged by geographical region, will assist in identifying native frogs that are sometimes mistaken for cane toads. Many of these native frogs burrow and only emerge after rain. This sometimes gives the impression that they have suddenly ‘arrived’ in the area. Frogs can also vary greatly in colour and patterning, so these photographs should be used as a guide only.