"Caloprymnus campestris" was well adapted to the extremely barren and arid regions it inhabited; these traits saved it from competition by introduced species like the rabbit or sheep. However, as early as the 1930s, the red fox had spread to the areas inhabited by the desert rat kangaroo. Thus, the rapid decline of the desert rat-kangaroo began shortly after its recovery in 1931 correlates with the invasion of its habitat by the fox. Predation by the red fox and cats, as well as variable seasonal patterns and overhunting by indigenous Australians, were blamed for the extinction of this species. No reliable reports of the species have been made since 1935, but unconfirmed sightings in Queensland followed periods of rain in 1956-1957 and 1974-1975. Also, recent remains of this species have been found in the mid 1980s inside caves. The desert rat-kangaroo was declared extinct in 1994, making it the only mammal species to be recovered and then lost again. In view of its amazing recovery following a 90-year period when it was not seen, the extinction of the desert rat-kangaroo is not certain; thus, sightings of this animal would not fall into the cryptozoology category. In similar cases, the broad-faced potoroo was last seen in the late 19th century and is considered extinct, Gilbert's potoroo was considered extinct for 120 years prior to its rediscovery in 1994, and the long-footed potoroo was only discovered in 1967. The finding of recent remains in the 1980s casts some doubt on the extinction of this species. Professor Ronald Nowak stated in his 2005 book, "perhaps a small population still survives, awaiting the time when it again may increase in response to proper conditions." An animal was sighted in May 2011 off Peake Station and subsequently identified from a museum skin as a desert rat-kangaroo. The area was then surveyed in August the same year. An old nest with some small macropod like scats was found and some tracks were also found near a waterhole that might have been made by the desert rat-kangaroo. However DNA analysis of the scats failed to yield any usable DNA. No DNA was found in dingo and cat scats in the area as well. As such the sighting remains unconfirmed, but researchers Tony Robinson and Tiana Forrrest confirmed the possibility "that a small population of "Caloprymnus", generally considered to be extinct throughout its former range across the Lake Eyre Basin, may have been present in this area in May 2011".