In the early 1990s declines in populations of the northern tinker frog were so huge it was thought that the species may have been driven to extinction; surveys from 1991 to 1994 failed to find any individuals. However, later in the decade small numbers of individuals were heard calling again. The genus Taudactylus, known as torrent frogs, contains just six species, and is highly threatened with extinction; four of the species have been classified by the IUCN as Critically Endangered, one as Near Threatened, and one as Extinct. Chytrid fungus is the suspected cause of declines in the torrent frogs, and is known to have caused the extinction of two closely related species from the same part of Queensland.