Native to both South and Central America, Cane toads were introduced to Australia in the 1930s and have since become an invasive species and a threat to the continent's native predators and scavengers. The primary mechanism of impact cane toads have on Australian ecosystems is through poisoning of native species. The parotoid gland on either side of the head of a cane toad produces a secretion containing bufadienolides that is toxic to most animals. This chemical defence does not exist in any native Australian anuran. Consequently, many native animals that prey on anurans experienced significant population decline, immediately following the invasion of the toad species in Australia. Whilst the invasion of cane toads has had devastating impacts on the populations of native predators in many Australian ecosystems in which the species has spread, it is unlikely that cane toads are solely responsible for the extinction of any native species. Furthermore, many of the populations that initially experienced a decline following the invasion of cane toads, have subsequently been observed to recover. The persistence of these populations suggests that over time, native predator species have adapted to the presence of the cane toad. Native predators may have adjusted to the ubiety of the toxic anuran through learning or as a result of evolutionary selective pressures applied by the invader. (en)