Animal Diversity Web

Ge­o­graphic Range

Dusky hop­ping-mice are dis­trib­uted from Ooldea in S Aus­tralia to past Lake Eyre to SW Queens­land. They also cur­rently in­habit the re­gions of SE West­ern Aus­tralia, S North­ern Ter­ri­tory, South­ern Aus­tralia, N New South Wales, and NE South Aus­tralia (south­ern Strzeleki Desert and the Cob­blers Desert). Since 1985, N. fus­cus spec­i­mens have been col­lected from Car­raweena, Mon­tecol­lina Bore and Quinyam­bie Sta­tion, and from Pel­i­can Wa­ter­hole. (Grizmick 1990, Honaki 1982, Nowak 1991, Ro­dent Ac­tion Plan http://​www.​anca.​gov.​au/​plants/​threaten/​sched123.​htm)

• Biogeographic Regions
• australian
  • native

Habi­tat

Dusky hop­ping-mice in­habit sand dunes, grass­lands, tree and shrub heaths, and lightly wooded areas. The tem­per­a­ture of their habi­tat is usu­ally very high with desert-like con­di­tions. N. fus­cus also live in sand ridge habi­tats, which al­ter­nate with gib­ber flats and clay pans, in the Pel­i­can Wa­ter­hole area. (Grizmick 1990, Honaki 1982, Nowak 1991, Ro­dent Ac­tion Plan

http://​www.​anca.​gov.​au/​plants/​threaten/​sched123.​htm)

• Terrestrial Biomes
• desert or dune
• savanna or grassland

Phys­i­cal De­scrip­tion

N. fus­cus is char­ac­ter­ized by its strong in­cisor teeth, long tail, large ears, dark eyes, and ex­tremely length­ened and nar­row hind feet, which have only four sole pads. Head and body length is 91-177 mm, tail length is 125-225 mm, and weight is about 20-50 grams. Col­oration of the upper parts varies from pale sandy brown to yel­low­ish brown to ashy brown or gray­ish. The un­der­parts of dusky hop­ping-mice are white. The body cov­er­ing is fine, close and soft; and long hairs near the tip of the tail give the ef­fect of a brush. No­to­mys fus­cus has a well-de­vel­oped se­ba­ceous glan­du­lar area on the un­der­side of its neck or chest. Fe­males have four mam­mae. (Grizmick 1990, Honaki 1982, Nowak 1991)

• Other Physical Features
• endothermic
• bilateral symmetry

Re­pro­duc­tion

Lit­tle is known of the breed­ing bi­ol­ogy of this species in the wild other than that it is an op­por­tunis­tic breeder. In cap­tiv­ity, its breed­ing pat­tern is polye­strous, with no ev­i­dence of sea­son­al­ity, thus it breeds through­out the year. The ges­ta­tion pe­riod is 38-41 days; a post­par­tum es­trus is not com­mon in N. fus­cus, but some fe­males enter es­trus 14-22 days after giv­ing birth. The es­trous cycle lasts about 7-8 days. Dusky hop­ping-mice rear lit­ters of 1-5 young. Their young weigh about 2-4 grams at birth and open their eyes at 18-28 days. The young cling to the nip­ples of the mother and are dragged about wher­ever she goes, and wean­ing oc­curs at about 30 days. Both sexes of N. fus­cus reach re­pro­duc­tive ma­tu­rity at 70 days. It was seen that one fe­male N. fus­cus pro­duced 9 lit­ters in her life­time of 26 months. Males are ca­pa­ble of breed­ing up to the age of 38 months. (Grizmick 1990, Honaki 1982, Nowak 1991)

• Key Reproductive Features
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual

Be­hav­ior

The se­ba­ceous glan­du­lar area is ac­tive in all adult males but is ac­tive in fe­males only dur­ing preg­nancy and lac­ta­tion. Nowak (1991) sug­gests that the glands are used for ter­ri­to­r­ial mark­ing and mark­ing of group mem­bers, in­clud­ing new­born young. Dusky hop­ping-mice are salta­to­r­ial and nor­mally move awk­wardly on all fours or make short hops. If star­tled, they bound rapidly using only their large hind feet. The mice dig their own bur­rows, some being of a sim­ple con­struc­tion but oth­ers being com­plex. The dusky hop­ping-mouse digs a bur­row on the flat top of a dune with a sin­gle tun­nel about 10 cm in di­am­e­ter, more than a meter below the sur­face and up to 5 m long. It is con­nected to the sur­face by up to 6 ver­ti­cal en­trance shafts that are dug from below and may end up any­where on the sur­face. A nest, con­sist­ing of a pad of finely chewed veg­e­ta­tion, is placed in the cen­ter of a small al­cove off the main shaft, and well-marked pads con­nect dif­fer­ent bur­rows along the top of the dune. The width of the en­trance shafts is crit­i­cal be­cause the an­i­mals move in them by hop­ping; they brace their backs against the sides with their forefeet be­tween hops. Progress when com­ing down a shaft is a head­long dive, with the back braced against the wall of the shaft and the forelegs used as a brake. If the en­ter­ing an­i­mal finds that the bur­row is blocked with loose sand, it often squeaks sev­eral times. This usu­ally at­tracts other oc­cu­pants and to­gether, from op­po­site sides, they rapidly clear the block­age. N. fus­cus is com­monly found in as­so­ci­a­tion with mar­su­pial coun­ter­parts and some­times shares the same tun­nel sys­tems. Liv­ing in groups of about five in­di­vid­u­als in one or two ad­ja­cent bur­rows sys­tems, the Dusky Hop­ping-mouse spends all its life on the dunes. Being a noc­tur­nal an­i­mal, it rests in its bur­row dur­ing the day, in­su­lated from the hot sur­face. At night, it for­ages on the top and sides of a dune, and rarely ven­tures more than a few me­ters away. Even in ap­par­ently fa­vor­able lo­cal­i­ties, pop­u­la­tion den­sity is low, with in­di­vid­u­als in­con­spic­u­ously con­gre­gated in a loose colony in a small area of a sand­hill. Dusky Hop­ping-mice calls in­clude twit­ter­ing dur­ing an­i­mated chases. How­ever, none of the sounds was as­so­ci­ated with threats or fight­ing. (Grizmick 1990, Honaki 1982, Nowak 1991)

• Key Behaviors
• motile

Com­mu­ni­ca­tion and Per­cep­tion

• Perception Channels
• tactile
• chemical

Food Habits

No­to­mys fus­cus is like other hop­ping-mice in that it does not drink, but ob­tains all its water and food re­quire­ments from a diet of seeds, berries, leaves, green plants and oc­ca­sion­ally in­sects. (Grizmick 1990, Honaki 1982, Nowak 1991)

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

No­to­mys fus­cus is used in stud­ies of re­pro­duc­tion be­cause of its rapid breed­ing cycle. Some stud­ies have in­cluded fe­male and male N. fus­cus re­pro­duc­tive anatomy and phys­i­ol­ogy, while other stud­ies have fo­cused on ge­netic analy­ses. (Baver­stock 1977, Breed 1982, Breed 1985)

Con­ser­va­tion Sta­tus

The N. fus­cus pop­u­la­tion is very small, and the species is rarely seen in its known habi­tats. Re­cent cap­ture rates sug­gests the num­bers of dusky hop­ping-mice to be 10 000. The rea­son for de­cline in `N. fus­cus <<No­to­mys fus­cus>` pop­u­la­tion size is not known. No­to­mys fus­cus is noted in the lists of ANZECC, and in Ap­pen­dix II of the Con­ven­tion in In­ter­na­tional Trade of En­dan­gered Species (CITES). IUCN con­sid­ers N. fus­cus to be a vul­ner­a­ble taxon with pop­u­la­tions that have been se­ri­ously de­pleted and whose ul­ti­mate se­cu­rity is not yet as­sured. There have been some ef­forts to as­sist the re­cov­ery of pop­u­la­tions of N. fus­cus by or­ga­ni­za­tions in­clud­ing the De­part­ment of En­vi­ron­ment and Nat­ural Re­sources, SA, and Qld De­part­ment of En­vi­ron­ment and Her­itage and Con­ser­va­tion Com­mis­sion of the North­ern Ter­ri­tory. Their re­cov­ery ob­jec­tives are to un­der­take a sur­vey to de­ter­mine the species' cur­rent dis­tri­b­u­tion, pop­u­la­tion size, and habi­tat re­quire­ments. (Refu­gia for Bi­o­log­i­cal Di­ver­sity in Arid and Semi-arid Aus­tralia http://​kaos.​erin.​gov.​au/​life/​general_​info/​biodivser_​4/​bio119.​html

Ro­dent Ac­tion Plan http://​www.​anca.​gov.​au/​plants/​threaten/​sched123.​htm)

• IUCN Red List

  Vulnerable
  More information

Other Com­ments

No­to­mys fus­cus means dusky south­ern mouse. Their large ears are not only for pick­ing up sounds of preda­tors but are also an adap­ta­tion for liv­ing in ex­treme heat. The large sur­face area of the ears al­lows the blood to flow and cool in the air, thus low­er­ing the body tem­per­a­ture by low­er­ing the tem­per­a­ture of the blood. Key threats are graz­ing by stock and rab­bits. Like other arid zone ro­dents, N. fus­cus is sub­ject to pe­ri­odic pop­u­la­tion fluc­tu­a­tions. The num­bers in the pop­u­la­tion fol­low the sea­sons of good rain­fall and plant growth. In times of sparse rain­fall, N. fus­cus is well adapted for sur­vival on ac­count of its abil­ity to ex­crete waste ni­tro­gen in the form of one of the most highly con­cen­trated urines known in a ro­dent. (Grizmick 1990, Honaki 1982, Nowak 1991, Refu­gia for Bi­o­log­i­cal Di­ver­sity in Arid and Semi-arid Aus­tralia http://​kaos.​erin.​gov.​au/​life/​general_​info/​biodivser_​4/​bio119.​html, Ro­dent Ac­tion Plan http://​www.​anca.​gov.​au/​plants/​threaten/​sched123.​htm)

Con­trib­u­tors

Ken­neth Kim (au­thor), Uni­ver­sity of Michi­gan-Ann Arbor.

Ref­er­ences

Baver­stock, PR. Poly­mor­phism of the X-Chro­mo­some, Y-Chro­mo­some and Au­to­somes in the Aus­tralian Hop­ping Mice N. fus­cus. Chro­mo­soma.. 1977. 61(3): 243-56.

Breed, WG. Mor­pho­log­i­cal vari­a­tion in testes and ac­ces­sory or­gans of Aus­tralian ro­dents in gen­era No­to­mys. Jour­nal of Re­pro­duc­tive Fer­til­ity. 1982. 66(2): 607-13

Breed, WG. Mor­pho­log­i­cal vari­a­tion in fe­male re­pro­duc­tive tract of Aus­tralian ro­dents in gen­era No­to­mys. Jour­nal of Re­pro­duc­tive Fer­til­ity. 1985. 73(2): 379-84.

En­dan­gered Species in the Arid Zone http://​rubens.​anu.​edu.​au/​student.​projects/​rabbits/​endangered.​html

Grizmick, B. Grizmick's En­cy­clo­pe­dia of Mam­mals. Mc­Graw-Hill, Inc. New York, NY. 1990. 3: 202-203.

Honaki, J. Mam­mal Species of the World. Allen Press Inc. Lawrence, KA. 1982. 538.

Nowak, R. Walker's Mam­mals of the World. John's Hop­kins Uni­ver­sity Press. Bal­ti­more, MD. 1991. 824.

Refu­gia for Bi­o­log­i­cal Di­ver­sity in Arid and Semi-arid Aus­tralia http://​kaos.​erin.​gov.​au/​life/​general_​info/​biodivser_​4/​bio119.​html

Ro­dent Ac­tion Plan http://​www.​anca.​gov.​au/​plants/​threaten/​sched123.​htm

Wil­son, D. E., and D. M. Reeder. Mam­mal Species of the World, A Tax­o­nomic and Ge­o­graphic Ref­er­ence. 2nd edi­tion. Smith­son­ian In­sti­tu­tion Press, Wash­ing­ton. 1993. 2: 753.