until recently, the freshwater crocodile was common in northern australia, especially where saltwater crocodiles are absent (such as more arid inland areas and higher elevations). in recent years, the population has dropped dramatically due to the ingestion of the invasive cane toad. the toad is poisonous to freshwater crocodiles, although not to saltwater crocodiles, and the toad is rampant throughout the australian wilderness. the crocodiles are also infected by "griphobilharzia amoena", a parasitic trematode, in regions such as darwin.