Animal Diversity Web

Ge­o­graphic Range

There is only one ex­tant pop­u­la­tion of Gilbert's po­toroos. This pop­u­la­tion lives in the Two Peo­ple's Bay park area of West­ern Aus­tralia. (Sin­clair, et al., 2000)

• Biogeographic Regions
• australian
  • native

Habi­tat

Gilbert's po­toroos are en­tirely ter­res­trial. In the Two Peo­ple's Bay park area, the po­toroos hide from preda­tors in the brushy un­der­growth. Other mem­bers of the genus Po­torous also pre­fer liv­ing in thick scrub, for­est, low bushes, or long grass. (Ly­dekker, 1896; Lyne, 1967; Sin­clair, et al., 2002)

• Habitat Regions
• tropical
• terrestrial

• Terrestrial Biomes
• savanna or grassland
• scrub forest

Phys­i­cal De­scrip­tion

Gilbert's po­toroos mea­sure ap­prox­i­mately 558 mm in length, with the tail tak­ing up 158 mm of this total. The short, silky coat of Gilbert's po­toroos are gray­ish-brown, fad­ing to a red­dish-brown color on the back. The under parts are whitish-gray, and the tail con­sists of hairs which are gray at the base turn­ing into black at the tips. The face is long and nar­row with a black line run­ning from the nose to the fore­head. (Harper, 1945; Ly­dekker, 1896)

• Other Physical Features
• endothermic
• homoiothermic
• bilateral symmetry

• Average length

  558 mm

  21.97 in

Re­pro­duc­tion

The re­pro­duc­tive be­hav­ior of Gilbert's po­toroos has not yet been stud­ied in de­tail by sci­en­tists. In Po­torous tri­dacty­lus, the mat­ing sys­tem is polyg­a­mous. Gilbert's po­toroos may share a sim­i­lar mat­ing sys­tem. (Nowak, 1991)

The re­pro­duc­tive be­hav­ior of Gilbert's po­toroos has not yet been stud­ied in de­tail by sci­en­tists. How­ever, re­pro­duc­tion in Po­torous tri­dacty­lus has been well doc­u­mented, and it is likely that Po­torous gilber­tii is sim­i­lar in many re­spects. The fol­low­ing in­for­ma­tion per­tains to P. tri­dacty­lus.

Fe­males typ­i­cally breed two times a year at any time dur­ing the year. Lit­ters al­ways con­taint a sin­gle pup, which is born after a ges­ta­tion pe­riod of ap­prox­i­mately 38 days. Fe­males may breed again im­me­di­ately after giv­ing birth, but the newly con­ceived em­bryo re­mains dor­mant and im­plan­ta­tion is de­layed for at least four and a half months, or until the first pup dies. Fe­males can breed start­ing at one year of age. New­born pups mea­sure 3/4 inches long at the time of birth. It takes 10 min­utes for the pup to crawl to the mother's pouch. In the pouch, the pup at­taches to a teat, where it re­mains for two months. Pups con­tinue to suckle until four months of age. (Lyne, 1967; Nowak, 1991)

• Key Reproductive Features
• iteroparous
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual
• fertilization
  • internal
• viviparous

• Breeding interval

  The breeding interval of P. gilbertii has not been documented, but if these animals are like other members of the genus, they probably breed twice per year.

• Breeding season

  The breeding season for this species has not been documented.

Parental care in Po­torous gilberti has not been de­scribed. How­ever, as mar­su­pial mam­mals, some gen­er­al­iza­tions about these po­toroos can be made. It is likely that most parental care is pro­vided by the mother, first when the off­spring is in her pouch, and later when it be­comes more mo­bile. Fe­males typ­i­cally pro­vide their young with pro­tec­tion, groom­ing, and food while they are still de­pen­dent. (Nowak, 1991)

• Parental Investment
• altricial
• pre-fertilization
  • provisioning
  • protecting
    • female
• pre-hatching/birth
  • provisioning
    • female
  • protecting
    • female
• pre-weaning/fledging
  • provisioning
    • female
  • protecting
    • female

Lifes­pan/Longevity

The lifes­pan of Po­torous gilber­tii is un­known, but its close rel­a­tive, Po­torous tri­dacty­lus, is known to live up to 7 years in the wild and up to 12 years in cap­tiv­ity. (Nowak, 1991)

Be­hav­ior

Lit­tle is known about the be­hav­ior of Gilbert's po­toroos. How­ever, Po­torous tri­dacty­lus, a closely re­lated species, is pri­mar­ily noc­tur­nal. Males are con­sid­ered ter­ri­to­r­ial, but they de­fend home ranges only when nearby fe­males are in es­trus. Po­torous tri­dacty­lus typ­i­cally lives a in sim­ple nest, with fe­males spend­ing a par­tic­u­larly large amount of time nest­ing while they are breed­ing. (Nowak, 1991)

• Key Behaviors
• motile

Home Range

In­for­ma­tion on the home ranges of P. gilber­tii is not avail­able.

Com­mu­ni­ca­tion and Per­cep­tion

The com­mu­ni­ca­tion pat­terns of of Gilbert's po­toroos are un­known. How­ever, as with other mar­su­pial mam­mals, these crea­tures can per­ceive vi­sual stim­uli, noises, and smells. It is not known what role scent, vi­sual sig­nals, or vo­cal­iza­tions play in their com­mu­ni­ca­tion. (Nowak, 1991)

• Perception Channels
• visual
• tactile
• acoustic
• chemical

Food Habits

The food habits of Gilbert's Po­toroos have not been stud­ied, but one can infer that it is pri­mar­ily her­biv­o­rous by study­ing the habits of its rel­a­tive, Po­torous tri­dacty­lus. Fungi are the major food of Po­torous tri­dacty­lus, al­though these po­toroos will also con­sume roots, grass, other veg­eta­bles, and an oc­ca­sion­ally in­sect in the sum­mer­time. The roots and tu­bers are dug up with the po­toroo's fore­claws. Po­torous gilber­tii re­port­edly digs holes in the ground while feed­ing, so it is likely that it is feed­ing on roots or fungi, also. (Mar­low, 1968; Nowak, 1991)

Pre­da­tion

Pre­da­tion by in­tro­duced Eu­ro­pean foxes and feral cats is thought to have played a major role in the dis­ap­pear­ance of Gilbert's po­toroos. Re­searchers be­lieve that the tiny pop­u­la­tion of Gilbert's po­toroos in Two Peo­ple's Bay man­aged to sur­vive be­cause the park did not em­ploy the usual method of burn­ing veg­e­ta­tion in the park. This extra brush gave the po­toroos a place to hide from preda­tors and al­lowed them to sur­vive to the pre­sent. In ad­di­tion, some field re­searchers re­port that Na­tives in Aus­tralia would oc­ca­sion­ally kill the po­toroos in large num­bers. (Harper, 1945; Sin­clair, et al., 2000)

• Known Predators

  • Humans Homo sapiens
  • Foxes Vulpes vulpes
  • Feral cats Felis sylvestris catus

Ecosys­tem Roles

The role that Gilbert's po­toroos play in their local ecosys­tem is un­known. How­ever, it can be in­ferred from their food habits that they mod­ify the veg­e­ta­tion in com­mu­ni­ties in which they live, and may dis­turb the soil, in­flu­enc­ing plant re­gen­er­a­tion.

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

It is not known whether Gilbert's po­toroos have any pos­i­tive ef­fects on human pop­u­la­tions. Al­though there are re­ports that P. gilber­tii was for­merly hunted, be­cause of the species' cur­rent re­stricted dis­tri­b­u­tion, it is not likely that it is a sig­nif­i­cant re­source to in­dige­nous peo­ples.

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

It is not known whether Gilbert's po­toroos have any neg­a­tive ef­fects on human pop­u­la­tions. Al­though the closely re­lated species, Po­torous tri­dacty­lus, is con­sid­ered a pest by many farm­ers be­cause it causes dam­age to potato crops by scratch­ing for food in the ground, it is not likely that Gilbert's po­toroos are a sig­nif­i­cant pest be­cause of their re­stricted dis­tri­b­u­tion. (Ly­dekker, 1896)

Con­ser­va­tion Sta­tus

Gilbert's po­toroos are con­sid­ered one of Aus­tralia's most en­dan­gered mam­mals. Gilbert's po­toroos were pre­sumed ex­tinct until the species was re­dis­cov­ered in Two Peo­ple's Bay in 1994. Many dif­fer­ent fac­tors have con­tributed to the near ex­tinc­tion of this species. These in­clude pre­da­tion by in­tro­duced foxes and feral cats, dis­ease, poi­soned baits, and loss of land due to graz­ing cat­tle. Re­cent sci­en­tific stud­ies in­di­cate that the sin­gle known small pop­u­la­tion of Gilbert's po­toroos has ex­pe­ri­enced a dra­matic, re­cent ge­netic bot­tle­neck. The an­i­mals are likely vul­ner­a­ble to dis­ease due to lack of ge­netic vari­a­tion. To pre­vent the ex­tinc­tion of Gilbert's po­toroos, sci­en­tists es­ti­mate that the pop­u­la­tion must be in­creased to at least 500 in­di­vid­u­als in order to pro­vide suf­fi­cient ge­netic vari­a­tion (the cur­rent pop­u­la­tion size is un­known). To do this, the Two Peo­ple's Bay area must be con­served, local preda­tors must be con­trolled, cap­tive breed­ing pro­grams must be cre­ated, and searches for other pos­si­ble re­main­ing pop­u­la­tions of Gilbert's po­toroos should be con­ducted. (Gilbert's Po­toroo Ac­tion Group, 2004; Harper, 1945; Sin­clair, et al., 2000; Sin­clair, et al., 2002)

• IUCN Red List

  Critically Endangered
  More information

• IUCN Red List

  Critically Endangered
  More information

• US Federal List

  No special status

• CITES

  No special status

Con­trib­u­tors

Nancy Shef­ferly (ed­i­tor), An­i­mal Di­ver­sity Web.

Jen­nifer Gumas (au­thor), Michi­gan State Uni­ver­sity, Bar­bara Lun­dri­gan (ed­i­tor, in­struc­tor), Michi­gan State Uni­ver­sity.

Ref­er­ences

IUCN. 1997. "The IUCN Red List of Threat­ened Species" (On-line ). Ac­cessed 03/09/03 at http://​www.​redlist.​org.

Gilbert's Po­toroo Ac­tion Group, 2004. "Gilbert's Po­toroo - Aus­tralia's Most En­dan­gered Mam­mal" (On-line). Ac­cessed June 05, 2007 at http://​www.​potoroo.​org/​.

Harper, F. 1945. Ex­tinct and Van­ish­ing Mam­mals of the Old World. Bal­ti­more: The Lord Bal­ti­more Press.

Ly­dekker, R. 1896. A Hand­book to the Mar­su­pi­alia and Monotremata. Ed­ward Lloyd.

Lyne, G. 1967. Mar­su­pi­als and Monotremes of Aus­tralia. Syd­ney: Hal­sted Press.

Mar­low, B. 1968. Mar­su­pi­als of Aus­tralia. Hong Kong: Jacaranda.

Nowak, R. 1991. Po­toroos. Pp. 87-88 in Walker's Mam­mals of the World, Vol. 1, 5th Edi­tion. Bal­ti­more and Lon­don: The Johns Hop­kins Uni­ver­sity Press.

Sin­clair, E., B. Costello, J. Courte­nay, K. Cran­dall. 2002. De­tect­ing a ge­netic bot­tle­neck in Gilbert's Po­toroo (Po­torous gilber­tii) (Mar­su­pi­alia: Po­toroidae), in­ferred form mi­crosatel­lite and mi­to­chon­dr­ial DNA se­quence data. Con­ser­va­tions Ge­net­ics, 3: 191-196.

Sin­clair, E., A. Murch, M. Di Renzo, M. Palermo. 2000. Chro­mo­some mor­phol­ogy in Gilbert's po­toroo, Po­torous gilber­tii (Mar­su­pi­alia: Po­toroidae). Aus­tralian Jour­nal of Zo­ol­ogy, 48: 281-287.