Leporillus conditorgreater stick-nest rat

Ge­o­graphic Range

Greater stick-nest rats (Lep­o­ril­lus con­di­tor) once oc­cu­pied most of the south­ern arid and semi-arid re­gions of south­ern Aus­tralia in­clud­ing the local moun­tain ranges. Though greater stick-nest rats are widely dis­trib­uted across this re­gion, its dis­tri­b­u­tion is patchy as a re­sult of the patchy dis­tri­b­u­tion of its pre­ferred diet of peren­nial, semi-suc­cu­lent shrubs. Be­tween 1860 and 1930, the ge­o­graphic range of greater stick-nest rats de­clined dras­ti­cally due to the die-off of main­land pop­u­la­tions of the species. Even­tu­ally only two small, iso­lated pop­u­la­tions re­mained on the East and West Franklin Is­lands in the Nuyt’s Arch­i­pel­ago off the coast of South­ern Aus­tralia. In 1860, the first pop­u­la­tions dis­ap­peared around the area of the Mur­ray-Dar­ling con­flu­ence and in the Flinders Ranges re­gion. The die-off then spread, mov­ing from east to west and from south to north. Only 1000 rats on the East and West Franklin Is­lands are es­ti­mated to have sur­vived the 70 year pe­riod, lim­it­ing the species' cur­rent range. (Bar­clay, et al., 2006; Cop­ley, 1999; Moseby and Bice, 2004)

Habi­tat

Greater stick-nest rats pre­fer dune and dune base habi­tats in which large com­mu­nal nests are con­structed out of in­ter­wo­ven sticks, stones, straw, leaves, flow­ers, bones, and scats. Among eight rats mon­i­tored for eight months dur­ing a rein­tro­duc­tion trial within the Roxby Downs Arid Re­serve in Aus­tralia, shel­ters were built mostly in dead Um­brella Wat­tle (Aca­cia ligu­lata) or Nar­row-leafed Hop­bush (Dodon­aea vis­cosa) shrubs cov­ered in low veg­e­ta­tion. The wild pop­u­la­tion of greater stick-nest rats on the Franklin Is­lands use dense shrubs as well as Short-tailed shear­wa­ter nests (Puffi­nus tenu­riostris) for their nests. In ad­di­tion to shrub­bery, the rats may use rock crevices for shel­ter. No mat­ter the ma­te­r­ial used, cover from preda­tors, es­pe­cially those that hunt prey from the sky, is a im­por­tant re­quire­ment of the rat’s habi­tat. On the in­te­rior of these nests, the rats cre­ate cham­bers lined with fine sticks and stripped bark that form a se­ries of tun­nels that ra­di­ate from a cen­tral cham­ber. ("Ap­proved Con­ser­va­tion Ad­vice for Lep­o­ril­lus con­di­tor (Greater Stick-nest Rat)", 2003; Cop­ley, 1999; Moseby and Bice, 2004; Pear­son, et al., 2001; Robin­son, 1975)

Shel­ters can be built both above and un­der­ground, the lat­ter of which typ­i­cally con­tain more than one en­trance cov­ered with piles of sticks. The above ground shel­ters mea­sure less than 80 cm in di­am­e­ter and 50 cm in height. Most of the nest build­ing seems to be done by the adult fe­male. Greater stick-nest rats have also been ob­served uti­liz­ing un­der­ground bur­rows of other species. These large nests are com­mu­nal and in­hab­ited over mul­ti­ple suc­ces­sive gen­er­a­tions. In cap­tiv­ity, these nests have been doc­u­mented to house any­where from 10 to 20 in­di­vid­u­als at one time and con­sist of one adult fe­male, a few of her lit­ters, and usu­ally one adult male. The adult fe­male can often dis­play ag­gres­sion to­wards the male, how­ever, in which case the male will often seek shel­ter away from the main group. While more than one lit­ter may re­side in the den at one time, the young gen­er­ally do not stick around after the next lit­ter is born. If an adult fe­male is seen with an older young, how­ever, it is most likely a fe­male off­spring. In some re-in­tro­duced pop­u­la­tions on off­shore is­lands, fe­male rats may oc­cupy small, rel­a­tively sta­ble den areas, while the male rats oc­cupy a wider range of den sites. ("Ap­proved Con­ser­va­tion Ad­vice for Lep­o­ril­lus con­di­tor (Greater Stick-nest Rat)", 2003; Cop­ley, 1999; Moseby and Bice, 2004; Pear­son, et al., 2001; Robin­son, 1975)

Phys­i­cal De­scrip­tion

Greater stick-nest rats have fluffy yel­low­ish-brown to grey fur. Their bel­lies are cream col­ored and their hind feet have dis­tinc­tive white mark­ings on the upper sur­faces. Greater stick-nest rat bod­ies are com­pact and ac­ces­sorized with large ears and a blunt nose. Their in­cisors are con­tin­u­ally grow­ing, which al­lows them to con­sume hard seeds and carry sticks for nest build­ing. Greater stick-nest rats can get up to 26 cm long and weigh up to 450 g. The av­er­age weight for both male and fe­male adults is 300 g and the av­er­age weight for both male and fe­male sub adults is less than 150 g. ("Ap­proved Con­ser­va­tion Ad­vice for Lep­o­ril­lus con­di­tor (Greater Stick-nest Rat)", 2003; Cop­ley, 1999; Moseby and Bice, 2004)

  • Sexual Dimorphism
  • sexes alike
  • Range mass
    450 (high) g
    15.86 (high) oz
  • Average mass
    300 g
    10.57 oz
  • Range length
    26 (high) cm
    10.24 (high) in

Re­pro­duc­tion

Greater stick-nest rats mate op­por­tunis­ti­cally. One study mon­i­tored eight rats within the Arid Re­serve in Roxby Downs, in which all males were fre­quently seen fol­low­ing and try­ing to mate with the same sin­gle adult fe­male. Lit­tle other in­for­ma­tion ex­ists on the mat­ing sys­tems of greater stick-nest rats; how­ever old world rats and mice tend to have polyan­drous mat­ing sys­tems. (Moseby and Bice, 2004)

The lit­ter sizes of greater stick-nest rats greatly de­pends on whether the in­di­vid­ual lives in the wild or in cap­tiv­ity. In the wild, they typ­i­cally give birth to one to two young, whereas in cap­tiv­ity they have up­wards of four. The oe­strous cycle is 14 days but seems to be very ir­reg­u­lar. Based on data col­lected from only one male greater stick-nest rat, the testes/body mass per­cent­age is 2.14 g and the sperm length is 91 mi­crom­e­ters. (Breed and Tay­lor, 2000; Cop­ley, 1999; Woot­ton, 1987; Yom-Tov, 1985)

  • Breeding interval
    Greater stick-nest rat populations on the Franklin Islands breed year round.
  • Range number of offspring
    4 (high)
  • Average gestation period
    44 days
  • Range weaning age
    30 to 40 days
  • Average age at sexual or reproductive maturity (female)
    8 months
  • Average age at sexual or reproductive maturity (male)
    8 months

Greater stick-nest rat young are born in the nest and are car­ried around firmly at­tached to the mother’s teats. The young grow quickly and at two months of age they are up and on their own feet--though they will still get an oc­ca­sional ride from the mother. As the young grow older, they are car­ried around less and be­come more in­de­pen­dent. (Cop­ley, 1999)

  • Parental Investment
  • female parental care
  • pre-weaning/fledging
    • provisioning
      • female
    • protecting
      • female
  • pre-independence
    • provisioning
      • female
    • protecting
      • female

Lifes­pan/Longevity

Greater stick-nest rats may live up to five years. ("Alice Springs Desert Park", 2011)

  • Range lifespan
    Status: wild
    5 (high) years

Be­hav­ior

Lit­tle in­for­ma­tion ex­ists re­gard­ing the gen­eral be­hav­ior of greater stick-nest rats. Much of the cur­rent in­for­ma­tion is based upon the be­hav­ior of eight greater stick-nest rats mon­i­tored for eight months at the Arid Re­cov­ery Re­serve. Every male rat’s areas of ac­tiv­ity over­lapped and most al­ways cen­tered around the same older fe­male’s area of ac­tiv­ity. This main fe­male’s shel­ter was also shared by all the males. The other two res­i­dent fe­males were most often found alone, though they were oc­ca­sion­ally found to­gether in a pair. Only one of the adult male rats spent any men­tion­able amount of time with the non-main adult fe­male, but only at night and after she had be­come sex­u­ally ma­ture. Greater stick-nest rats are a rel­a­tively seden­tary species that are well known for their gen­tle and placid na­ture. They are largely noc­tur­nal. ("Arid Re­cov­ery", 2012; Cop­ley, 1999; Moseby and Bice, 2004)

Home Range

Based on the eight mon­i­tored rats at the Arid Re­serve, when greater stick-nest rats ven­tures out at night, they gen­er­ally stay within 150 m of their day­time shel­ter sites. (Moseby and Bice, 2004)

Com­mu­ni­ca­tion and Per­cep­tion

Lit­tle is known about greater stick-nest rats com­mu­ni­ca­tions and per­cep­tions.

Food Habits

Greater stick-nest rats re­sid­ing in cap­tiv­ity have a widely var­ied diet of fo­liage, flow­ers, seeds, and fruits from a di­verse range of arid zone plant species. The leaves and shoots of suc­cu­lent and semi-suc­cu­lent shrubs seem to be pre­ferred by the an­i­mals. Cheno­pod and other plant species that con­tain large amounts of water are also strongly pre­ferred. Specif­i­cally, rats in cap­tiv­ity mainly con­sume com­mon peren­nial dune species such as blad­der salt­bush (Atriplex vesi­caria), ruby salt­bush (Enchy­laena to­men­tosa) and Sturt’s pig­face (Gun­niop­sis quadri­fida), the lat­ter being the most heav­ily browsed. Gun­niop­sis quadri­fida and Ca­lan­drinia re­mota are also com­monly grazed upon due to their high water con­tent. On the Franklin Is­lands, the diet of greater stick-nest rats con­sist al­most en­tirely of leaves and fruits from suc­cu­lent plants in­clud­ing Rhago­dia cras­si­fo­lia, Ni­traria bil­lardierei, Car­po­bro­tus rossii and Tetrag­o­nia im­plex­i­coma, as well as a small per­cent­age of grasses. (Cop­ley, 1999; Moseby and Bice, 2004; Ryan, et al., 2003)

Greater stick-nest rats are not heavy graz­ers, typ­i­cally eat­ing small amounts of tis­sue from an in­di­vid­ual plant at one time, most often at the tips of leaves. In cap­tiv­ity, rats spend much of their time for­ag­ing on top of and at the bases of the dunes. They were rarely seen wan­der­ing fur­ther than 150 m from day­time shel­ter sites. They most typ­i­cally for­age when they are cov­ered by sur­round­ing brush and nor­mal noc­tur­nal ac­tiv­ity was seen in adult males that seemed to be loosely aimed to­wards for­ag­ing ef­forts. Greater stick-nest rats have been known to be quite re­source­ful and flex­i­ble in their for­ag­ing strate­gies, climb­ing bushes and pulling down branches to reach the youngest and ripest parts of the plant and rum­mag­ing through leaf lit­ter to pick out seeds. (Moseby and Bice, 2004; Ryan, et al., 2003)

  • Plant Foods
  • leaves
  • wood, bark, or stems
  • fruit
  • flowers

Pre­da­tion

When pop­u­la­tions of greater stick-nest rats first began to de­cline in 1860, it was be­lieved to be due to habi­tat de­struc­tion and the re­moval of food sources by large flocks of sheep. This was shortly fol­lowed by the drought of 1864-65, after which no greater stick-nest rats were recorded within their nat­ural habi­tat. Though all cur­rent pop­u­la­tions of greater stick-nest rats are heav­ily mon­i­tored and live in man­aged habi­tats, threats to the pop­u­la­tion still exist. Some of the threats in­clude in­tro­duced feral preda­tors, ex­ten­sive fire, dis­ease, and se­vere drought, but pre­da­tion by na­tive preda­tors re­mains the largest threat. On the Franklin Is­lands, greater stick-nest rats make up 91% of barn owls' diets and are also heav­ily pre­dated by black tiger snakes. On St. Pe­ters Is­land, the main preda­tors in­clude ex­tant pop­u­la­tion of black tiger snakes and sand goan­nas. On the main­land, din­gos pre­sent the largest threat. ("Ap­proved Con­ser­va­tion Ad­vice for Lep­o­ril­lus con­di­tor (Greater Stick-nest Rat)", 2003; Cop­ley, 1999)

Ecosys­tem Roles

Cer­tain cheno­pod plant species may be­come less abun­dant in the pres­ence of greater stick-nest rats due to their light, but con­tin­u­ous graz­ing. Also, greater stick-nest rats pre­fer some fe­male plants to male plants of Atriplex vesi­caria) due to a dif­fer­ence in water con­tent, thus skew­ing the pro­por­tion of male to fe­male plants within a pop­u­la­tion. How­ever, dur­ing the eight month mon­i­tor­ing pe­riod within the Arid Re­serve in Roxby Downs, no plant mor­tal­ity was ob­served in any plant species that was grazed upon by the eight res­i­dent rats. (Moseby and Bice, 2004; Ryan, et al., 2003)

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

Greater stick-nest rats are a widely ac­cepted can­di­date species for study­ing the ge­netic changes that occur within rein­tro­duced an­i­mal pop­u­la­tions. Twelve poly­mor­phic loci have been iso­lated and char­ac­ter­ized from greater stick-nest rats. These loci are being used to widen our un­der­stand­ing of pop­u­la­tion ge­net­ics and, more specif­i­cally, the ge­netic dif­fer­ences be­tween cap­tive and rein­tro­duced pop­u­la­tions. The con­clu­sions drawn from study­ing this can­di­date species may be ap­plied to ex­plain the ge­net­ics of other cap­tive and rein­tro­duced pop­u­la­tions. (Bar­clay, et al., 2006)

  • Positive Impacts
  • research and education

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

Lit­tle is known of the neg­a­tive eco­nomic im­por­tance that greater stick-nest rats have to hu­mans.

Con­ser­va­tion Sta­tus

Be­gin­ning in the mid-1980’s, a cap­tive breed­ing and rein­tro­duc­tion pro­gram was started using the two na­tive pop­u­la­tions of greater stick-nest rats on the Franklin Is­lands. In 1997, 8 rats were rein­tro­duced within the Arid Re­cov­ery Re­serve north of Roxby Downs in north­ern South Aus­tralia. In April 1999, these same eight rats bred and the trial was con­sid­ered a suc­cess. In ad­di­tion to the Arid Re­cov­ery Re­serve in Roxby Downs, rein­tro­duced pop­u­la­tions of greater stick-nest rats cur­rently re­side on Salu­ta­tion Is­land, Heiris­son Prong (West­ern Aus­tralia), St. Peter Is­land, Reevesby Is­land, Venus Bay Con­ser­va­tion Park (South Aus­tralia), and The Sco­tia Sanc­tu­ary (New South Wales). Nu­mer­ous at­tempts to rein­tro­duce greater stick-nest rats to their na­tive range on the main­land of Aus­tralia have been recorded and failed due to pre­da­tion by na­tive and in­tro­duced preda­tors. Causes thought to have trig­gered the mas­sive de­cline of greater stick-nest rat pop­u­la­tions in­clude se­vere drought, habi­tat de­struc­tion from in­tro­duced do­mes­tic stock and Eu­ro­pean rab­bits, and pre­da­tion by na­tive and in­tro­duced preda­tors (e.g. barn owls, feral cats, and foxes). (Bar­clay, et al., 2006; Moseby and Bice, 2004; Ryan, et al., 2003)

Ex­ist­ing con­ser­va­tion plans in­clude the Threat Abate­ment Plan for Pre­da­tion by Eu­ro­pean Red Fox and the Arid Re­cov­ery Ini­tia­tive, which fa­cil­i­tates the mon­i­tor­ing and con­tin­ued re­search on Greater stick-nest rat pop­u­la­tions rein­tro­duced at the re­serve in Roxby Downs. ("Arid Re­cov­ery", 2012)

Other Com­ments

Greater stick-nest rats have large ears and a fluffy coat, giv­ing it a rab­bit-like ap­pear­ance lead­ing early Eu­ro­pean colonists to call it a rab­bit-rat. Greater stick-nest rats were once hunted for sport and con­sid­ered easy prey. Early ex­plor­ers and na­tive hunters have doc­u­mented set­ting the rat’s nests on fire or strate­gi­cally pulling them apart. As the rats would flee from their nests to es­cape the at­tack. Tthey would ei­ther be cap­tured by Abo­rig­ine dogs or hit with sticks and later eaten. Greater stick-nest rats are the last sur­viv­ing species from its genus. (Bar­clay, et al., 2006; Cop­ley, 1999)

Con­trib­u­tors

Ale­cia Stew­art-Mal­one (au­thor), Uni­ver­sity of Wis­con­sin-Stevens Point, Christo­pher Yahnke (ed­i­tor), Uni­ver­sity of Wis­con­sin-Stevens Point, Laura Podzikowski (ed­i­tor), Spe­cial Pro­jects.

Glossary

Australian

Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.

World Map

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

colonial

used loosely to describe any group of organisms living together or in close proximity to each other - for example nesting shorebirds that live in large colonies. More specifically refers to a group of organisms in which members act as specialized subunits (a continuous, modular society) - as in clonal organisms.

desert or dunes

in deserts low (less than 30 cm per year) and unpredictable rainfall results in landscapes dominated by plants and animals adapted to aridity. Vegetation is typically sparse, though spectacular blooms may occur following rain. Deserts can be cold or warm and daily temperates typically fluctuate. In dune areas vegetation is also sparse and conditions are dry. This is because sand does not hold water well so little is available to plants. In dunes near seas and oceans this is compounded by the influence of salt in the air and soil. Salt limits the ability of plants to take up water through their roots.

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

female parental care

parental care is carried out by females

folivore

an animal that mainly eats leaves.

frugivore

an animal that mainly eats fruit

herbivore

An animal that eats mainly plants or parts of plants.

introduced

referring to animal species that have been transported to and established populations in regions outside of their natural range, usually through human action.

island endemic

animals that live only on an island or set of islands.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nocturnal

active during the night

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

territorial

defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

year-round breeding

breeding takes place throughout the year

Ref­er­ences

2011. "Alice Springs Desert Park" (On-line). Ac­cessed April 28, 2012 at http://​www.​alicespringsdesertpark.​com.​au/​kids/​nature/​mammals/​nestrat.​shtml.

2003. "Ap­proved Con­ser­va­tion Ad­vice for Lep­o­ril­lus con­di­tor (Greater Stick-nest Rat)" (On-line pdf). Ac­cessed Jan­u­ary 19, 2012 at http://​www.​environment.​gov.​au/​biodiversity/​threatened/​species/​pubs/​137-conservation-advice.​pdf.

2012. "Arid Re­cov­ery" (On-line). Ac­cessed Jan­u­ary 18, 2012 at http://​www.​aridrecovery.​org.​au/​index.

Bar­clay, S., B. Costello, W. Sher­win. 2006. Lim­ited cross-species mi­crosatel­lite am­pli­fi­ca­tion and the iso­la­tion and char­ac­ter­i­za­tion of new mi­crosatel­lite mark­ers for the greater stick-nest rat (Lep­o­ril­lus con­di­tor). Mol­e­c­u­lar Ecol­ogy Notes, 6: 882-885.

Breed, W., J. Tay­lor. 2000. Body Mass, Testes Mass, and Sperm Size in Murine Ro­dents. Jour­nal of Mam­mal­ogy, 81: 758-768.

Bur­bidge, A., M. Williams. 1997. Mam­mals of Aus­tralian Is­lands: Fac­tors In­flu­enc­ing Species Rich­ness. Jour­nal of Bio­geog­ra­phy, 24: 703-715.

Cop­ley, P. 1999. Nat­ural his­to­ries of Aus­tralia's stick-nest rats, genus Lep­o­ril­lus (Ro­den­tia:Muri­dae). Wildlife Re­search, 26: 513-539.

Lo­molino, M., R. Chan­nell. 1995. Splen­did Iso­la­tion: Pat­terns of Ge­o­graphic Range Col­lapse in En­dan­gered Mam­mals. Jour­nal of Mam­mal­ogy, 76: 335-347.

Mor­ton, S. 1979. Di­ver­sity of Desert-Dwelling Mam­mals: A Com­par­i­son of Aus­tralia and North Amer­ica. Jour­nal of Mam­mal­ogy, 60: 253-264.

Moseby, K., J. Bice. 2004. A trial re-in­tro­duc­tion of the Greater Stick-nest Rat (Lep­o­ril­lus con­di­tor) in arid South Aus­tralia. Eco­log­i­cal Man­age­ment & Restora­tion, 5: 118-124.

Pear­son, S., A. Baynes, B. Triggs. 2001. The record of fauna, and ac­cu­mu­lat­ing agents of hair and bone, found in mid­dens of stick-nest rats (Genus Lep­o­ril­lus) (Ro­den­tia:Muri­dae). Wildlife Re­search, 28: 435-444.

Robin­son, A. 1975. The Stick­nest Rat, Lep­o­ril­lus con­di­tor, on Franklin Is­land, Nuyts Arch­i­pel­ago, South Aus­tralia. Aus­tralian Mam­mol­ogy, 1: 319-327.

Ryan, S., K. Moseby, D. Paton. 2003. Com­par­a­tive for­ag­ing pref­er­ences of the Greater Stick-nest Rat Lep­o­ril­lus con­di­tor and the Eu­ro­pean Rab­bit Oryc­to­la­gus cu­nicu­lus: Im­pli­ca­tions for re­gen­er­a­tion of arid lands. Aus­tralian Mam­mol­ogy, 25: 135-146.

Woot­ton, J. 1987. The Ef­fects of Body Mass, Phy­logeny, Habi­tat, and Trophic Level on Mam­malian Age at First Re­pro­duc­tion. Evo­lu­tion, 41: 732-749.

Yom-Tov, Y. 1985. The Re­pro­duc­tive Rates of Aus­tralian Ro­dents. Oe­colo­gia, 66: 250-255.