The big-eared hopping mouse (Notomys macrotis) is an extinct species of mouse, which lived in the Moore River area of south-western Australia. The big-eared hopping mouse was a small, rat-sized animal resembling a tiny kangaroo. It had large eyes and ears with a brush-tipped tail. It moved on its four legs when traveling at a slower pace, or by bounding upon its enlarged, padded, hind feet when traveling quickly. They mainly lived in sand dunes and made nests of leaves and other organic materials. The big-eared hopping-mouse was last collected in July 1843 near the Moore River, Western Australia, close to where New Norcia is now situated, and has not been seen since.
The big-eared hopping mouse was among many hopping mice to be extinct, and its absence from extensive sub-fossil collections suggests it was restricted to Western Australia.
Of the six taxa with ranges limited to Western Australia, five are considered threatened or vulnerable and one, the big-eared hopping mouse, is extinct. Under the Western Australian Wildlife Conservation Act of 1950, the hopping mouse is listed as "fauna presumed to be extinct" and under Commonwealth legislation, simply "extinct". We only know about the hopping mouse from two damaged specimen: one from which the location it was found in is unknown and one at Moore River in Western Australia.
Alternatively, murids may have entered Australia already differentiated into various groups. This potential is, however, limited by the total absence of rodents in the late Miocene Alcoota and Ongeva Local Faunas of the Northern Territory. Currently there is no evidence or scientific method to test these alternative scenarios.
Seven species of native Australian rodent have become extinct and several others have significantly declined in numbers since the settlement of Europeans in Australia. These rodents make up 48% of the total mammals extinct in Western Australia. The hopping mouse was probably the first Australian mammal to succumb to European settlers. Hopping mice are vulnerable to agriculture and pastoralism, as well as introduced cats. During a plague, mice can comprise up to 100% of the diet of a feral cat, lending support to the theory that feral cats were the primary cause of their extinction.
By the 1850s, feral cats inhabited the Western Australian wheatbelt; they targeted a number of larger rodents throughout Western Australia. However, extinction occurred before the red fox came to Western Australia. The big-eared hopping mouse had no defenses against Australia's introduced species. Its extinction can possibly be shown as a ramification of environmental alteration by humans, and predation is another likely possibility, but the true reason for the extinction is uncertain. Studies have also shown that small animals, such as the big-eared hopping mice need high resting metabolic rate to attain the large metabolic scope needed in order to regulate body temperature. Consequently, an animal with a high resting metabolic rate has "reduced mortality and increased longevity and fecundity".
Within the genus Notomys there exist two clades. The big eared hopping mouse Notomys macrotis is classified in the same clade as the short-tailed hopping mouse, Notomys amplus, and the great hopping mouse, Notomys sp, both of whom are extinct. They are classified together due to their similar size. It also shares similar morphology with the fawn hopping mouse, Notomys cervinus, and the long-tailed hopping mouse, Notomys longicaudatus, due to the fact that they all lack the derived reproductive tract of the spinifex hopping mouse (Notomys alexis) clade Its closest phylogenetic relative is probably Notomys cervinus.
Notes
- Woinarski, John Casimir Zichy, Andrew Burbidge, and Peter Harrison. The Action Plan for Australian Mammals 2012. CSIRO, 2014. Print.
- Webb, S. 2008 (August): Megafauna demography and late Quaternary climatic change in Australia: A predisposition to extinction. Boreas, Vol. 37, pp. 329–345.
- William Z. Lidicker, J.H. Calaby, A.K. Lee. 1989 Rodents: A World Survey of Species of Conservation Concern. IUCN, pp. 53–54.
- Morris, K.D. "Csiro Publishing." Csiro Publishing. 27. (2000): n. page. Web. 25 Oct. 2012. [http://www.publish.csiro.au/?act=view_file&file_id=WR97054.pdf]
- Morris, K. D. "The Status and Conservation of Native Rodents in Western Australia." Wildlife Research 27 (2000): 405-19. Csiro. Csiro. Web. [http://www.publish.csiro.au/?act=view_file&file_id=WR97054.pdf]