General Impact
Cane toads will eat “almost any terrestrial animal”, although they are more likely to consume those active at ground level during the night (Hinkley 1962). Covacevich and Archer, (1975) in their paper on the effects of the cane toad on indigenous verteberates in Australia, state that snakes, such as the carpet python, the black headed python, death adder and some other snakes have been found dead with the cane toad in their mouths or guts. Studies in Australia where the range of the cane toad is ever expanding have shown that the cane toad plays an important role in structuring native anuran communities (Crossland, 2000) via direct and indirect mechanisms and is thus a threat to the survival of native Australian fauna ( Catling,P.C et al.2003).
Toads have been implicated in the decline of populations of monitor lizards in Guam (Jackson 1962, Dryden 1965). Pernetta and Watling (1978) consider that the toads do not interact with native frogs because they use different habitats; the frogs are either along stream banks or in the foliage of dense forest. Villadolid (1956) found rats and mice in stomachs of toads in the Philippine Islands. Hinkley concluded that this toad is “economically neutral” because it consumes both “harmful” and “beneficial” invertebrates.
Secretions from the parotoid glands are produced when the toad is provoked or localised pressure is applied, such as a predator grasping the toad in its mouth (NRM, 2001). The toxic secretions are known to cause illness and death in both domestic and wild animals that come into contact with toads, such as dogs, cats, snakes and lizards. The toxin causes extreme pain if rubbed into the eyes (NRM, 2001). Human fatalities have been reported, but are probably confined to people who deliberately concentrate the toxin and then ingest it.
Overall, the major impacts are on predatory species that attempt to eat toads and then die; in particular, species that normally specialise amphibians, such as Mertens water monitor in northern Australia.
Location Specific Impacts:Hispaniola Is. (Atlantic Ocean) 
Predation: Bufo marinus are implicated in the decline of Hispaniola's amphibians. Maningrida (Australia)
Other: There is concern that the predation of Bufo marinus on native species may affect the ability of the indigenous Aboriginal people to collect traditional food sources.
Predation: Bufo marinus preys upon native animal species. Northern Territory (Australia)
Reduction in native biodiversity: Doody et al (2006) provided evidence of the direct impact of cane toads on the yellow-spotted monitor lizard (Varanus panoptes) and indirect impact on nest predation of the pig-nosed turtle (see Carettochelys insculpta in IUCN Red List of Threatened Species) eggs. The yellow-spotted monitor lizard and cane toads were surveyed for five years at two sites along the Daly River, Northern Territory, before and after the arrival of cane toads. Pig-nosed turtle nest predation was also surveyed for three years before, and one year after, the arrival of the toads. The authors conclude, "Collectively, our data and observations, combined with unpublished reports, indicate that: (1) cane toads arrived at our study sites during the wet seasons of 2003–04 and 2004–05; (2) the lizard V. panoptes readily succumbs to cane toad toxins; (3) V. panoptes has experienced a marked decline in relative population numbers coincident with the arrival of the toads at the site; and (4) V. panoptes has been reduced to such low numbers that it is currently no longer a significant predator of pig-nosed turtle (C. insculpta) eggs". Gordonvale (Australia)
Predation: Bufo marinus preys upon native animal species. Bermuda
Human nuisance: Bufo marinus create nusiance by drowning in domestic water tanks and polluting water supply (Varnham, 2006).
Threat to endangered species: Bufo marinus is implicated in decline of the 'Critically Endangered (CR)' Bermudian Skink (see Eumeces longirostris in IUCN Red List of Threatened Species) (Davenport et al., 2001 in Varnham, 2006). Dominican Republic
Predation: Bufo marinuss are implicated in the decline of Hispaniola's amphibians. Grenada
Disease transmission: Bufo marinus have been implicated as being reservoirs for the bacteria Leptospira interrogans, which causes Weil's disease (infectious jaundice) in humans. Guam
Reduction in native biodiversity: Bufo marinus have been implicated in the decline of populations of monitor lizards in Guam (Jackson 1962, Dryden 1965 in SPREP, 2000). Chichi-jima Is. (Japan)
Habitat alteration: Pollution of the freshwater supply by Bufo marinus eggs and tadpoles.
Predation: Predation upon the indigenous terrestrial fauna. Iriomotejima Is. (Japan)
Other: Iriomote cats (Prionailurus iriomotensis) may possibly be poisoned when trying to eat Bufo marinus. Montserrat
Reduction in native biodiversity: Bufo marinus may compete with, predate or poison native frog (possesses numerous poison glands). It is also likely to heavily predate upon native invertebrates (Daltry et al., undated in Varnham, 2006). Buka Is. (PNG) (Papua New Guinea)
Other: Indigenous predators (snakes and the water monitor) are poisoned when trying to eat Bufo marinus. Philippines
Predation: Villadolid (1956) found rats and mice in stomachs of Bufo marinus in the Philippine Islands. Gavutu Is. (Solomon Islands)
Other: Indigenous predators (snakes and the water monitor) are poisoned when trying to eat Bufo marinus. Guadalcanal Is. (Solomon Islands)
Other: Indigenous predators (snakes and the water monitor) are poisoned when trying to eat Bufo marinus. Malaita Is. (Solomon Islands)
Other: Indigenous predators (snakes and the water monitor) are poisoned when trying to eat Bufo marinus. Banika Is. (Solomon Islands)
Other: Indigenous predators (snakes and the water monitor) are poisoned when trying to eat Bufo marinus. Vanikoro Is. (Solomon Islands)
Other: Indigenous predators (snakes and the water monitor) are poisoned when trying to eat Bufo marinus.
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