Animal Diversity Web

Ge­o­graphic Range

Large-eared ten­recs are en­demic to the is­land of Mada­gas­car and are found in the south and south­west re­gions of the is­land. (Stephen­son, 2003)

• Biogeographic Regions
• ethiopian
  • native

• Other Geographic Terms
• island endemic

Habi­tat

Ge­ogale au­rita is found widely dis­trib­uted in dry, de­cid­u­ous for­est, gallery forests, and spiny bush in south­ern and south­west­ern Mada­gas­car. The species has also been ob­served in the rain­for­est of the south­east. These are en­vi­ron­ments with large an­nual vari­a­tions in rain­fall. (Stephen­son, 2003)

• Habitat Regions
• tropical
• terrestrial

• Terrestrial Biomes
• forest
• rainforest
• scrub forest

Phys­i­cal De­scrip­tion

Large-eared ten­recs are small, shrew-like ten­recs with very short, soft pelage, hair-cov­ered tails, and large pin­nae. Dor­sal col­oration is vari­able, rang­ing from light gray to light red­dish-brown. Ven­trally, these an­i­mals are buffy white. Large-eared ten­recs are among the small­est liv­ing ten­recs, with wild-caught an­i­mals rang­ing in body mass from 5.0 to 8.5 g. The length of the head and body is 60 to 75 mm, and the total body length in­clud­ing the tail can be be­tween 90 and 105 mm.

Cer­tain char­ac­ters dis­tin­guish G. au­rita from other ten­recs. The den­tal for­mula is 2/2 1/1 3/2 3/3 = 34, whereas most ten­recs have 36 teeth. Fur­ther­more, large-eared ten­recs are the only mem­ber of the fam­ily Ten­re­ci­dae that ex­ibit post­par­tum oestrus, which al­lows fe­males to suckle a first lit­ter while a sec­ond lit­ter is de­vel­op­ing in utero.

Ge­ogale au­rita is het­erother­mic, and body tem­per­a­tures par­al­lel the sur­round­ing tem­per­a­ture at all times of year, al­though body tem­per­a­tures higher than am­bi­ent tem­per­a­ture are ob­served in preg­nant and lac­tat­ing fe­males. Low meta­bolic rate is cor­re­lated with this rel­a­tively low body tem­per­a­ture.

Testes are ab­dom­i­nal in G. au­rita, as they are in all other ten­recs. Mem­bers of the fam­ily Ten­re­ci­dae have a cloaca into which both the in­testi­nal and gen­i­touri­nary tracts empty. (Stephen­son, 2003)

• Other Physical Features
• endothermic
• heterothermic
• bilateral symmetry

• Range mass

  5.0 to 8.5 g

  0.18 to 0.30 oz

• Average mass

  6.0 g

  0.21 oz

• Range length

  90 to 105 mm

  3.54 to 4.13 in

• Average basal metabolic rate

  0.043 W

  AnAge

Re­pro­duc­tion

In­for­ma­tion on the mat­ing sys­tems of these ten­recs was not avail­able in the lit­er­a­ture re­viewed. Mat­ing sys­tems of ten­recs in gen­eral are poorly known. Most ten­recs are soli­tary, al­though some species ap­pear to form sta­ble long-term bonds be­tween males and fe­males, in­di­cat­ing that they may mate monog­a­mously. It is not known at this time what mat­ing sys­tem is em­ployed by G. au­rita. (Nowak, 1999)

Mat­ing takes place from late Sep­tem­ber to March. Be­cause these an­i­mals have a post-par­tum es­trus, they can pro­duce mul­ti­ple lit­ters dur­ing that time. Coital lock oc­curs dur­ing cop­u­la­tion and can last for more than 20 min­utes. Large-eared ten­recs are ca­pa­ble of ar­rest­ing the de­vel­op­ment of lit­ters, thus the ges­ta­tion pe­riod varies be­tween 54 and 69 days. Lit­ter size varies from 1 to 5 in­di­vid­u­als, and the weights of the neonates range from 0.5 to 0.8 g. The off­spring are al­tri­cial, and are born with closed eyes and ears. Young are weaned soon after the open­ing of eyes, which takes place after 21 to 33 days of age. (Stephen­son, 2003)

• Key Reproductive Features
• iteroparous
• seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual
• fertilization
• viviparous
• embryonic diapause
• post-partum estrous

• Breeding interval

  It is not known how often these animals breed in the wild.

• Breeding season

  Breeding occurs in late September to March.

• Range number of offspring

  1 to 5

• Average number of offspring

  3.9

  AnAge

• Range gestation period

  54 to 69 days

• Range weaning age

  21 to 33 days

Parental care in this species has not been de­scribed. How­ever, be­cause G. au­rita is a mam­mal, we know that fe­males pro­vide ex­ten­sive ma­ter­nal care. Young are al­tri­cial, so it is likely that moth­ers pro­vide not just food to their young, but also pro­tec­tion, groom­ing, and shel­ter, until the time that the young are weaned and can care for them­selves. Male parental care is var­ied in mam­mals, and lack­ing spe­cific in­for­ma­tion for these ten­recs, it is im­pos­si­ble to spec­u­late upon. (Nowak, 1999; Stephen­son, 2003)

• 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 long-eared ten­recs liv­ing in the wild is un­known but in cap­tiv­ity they have been ob­served to live for more than two and a half years. (Stephen­son, 2003)

• Range lifespan
  Status: captivity

  more than two and a half (high) years

• Typical lifespan
  Status: captivity

  2.5 (high) years

Be­hav­ior

Large-eared ten­recs are noc­tur­nal, poor-sighted an­i­mals that de­pend on au­di­tory and ol­fac­tory senses. They are mostly soli­tary an­i­mals, but male-fe­male pairs are oc­ca­sion­ally found liv­ing in prox­im­ity to each other. These an­i­mals are het­erother­mic and enter daily tor­por. They can often be found tor­pid in­side fallen logs and cav­i­ties of sand. (Stephen­son, 2003)

• Key Behaviors
• terricolous
• nocturnal
• motile
• daily torpor
• solitary

Home Range

The size of home range for these an­i­mals has not been re­ported, but given their small size, ter­ri­to­ries and home ranges are not likely to be very large.

Com­mu­ni­ca­tion and Per­cep­tion

Large-eared ten­recs use sound to lo­cate their ter­mite prey. Being a noc­tur­nal an­i­mal with poor eye­sight, G. au­rita de­pends on au­di­tory and ol­fac­tory senses. As in all mam­mals, tac­tile com­mu­ni­ca­tion is im­por­tant be­tween mates as well as be­tween moth­ers and their off­spring. Ac­coustic com­mu­ni­ca­tion be­tween mem­bers of this species has not been re­ported, but may occur. (Nowak, 1999; Pevel­ing, et al., 2003; Stephen­son, 2003)

• Communication Channels
• tactile
• chemical

• Perception Channels
• visual
• tactile
• acoustic
• chemical

Food Habits

Large-eared ten­recs are spe­cial­ized in­sec­ti­vores show­ing a clear pref­er­ence for ter­mites. Their diet con­sists ex­clu­sively of arthro­pods, which they lo­cate by using sound. They may also show a sig­nif­i­cant pref­er­ence for cer­tain species. (Pevel­ing, et al., 2003)

• Primary Diet
• carnivore
  • insectivore

• Animal Foods
• insects

Pre­da­tion

Ge­ogale au­rita is preyed upon by var­i­ous groups of an­i­mals. Re­mains of large-eared ten­recs have been found in pel­lets from two species of owls: barn owls and Mada­gas­car long-eared owls. Other species ex­pected to be preda­tors of large-eared ten­recs are snakes, in­clud­ing Mala­gasy cat-eye snakes, which are as­so­ci­ated with the habi­tat where Ge­ogale is found, and car­ni­vores such as Mala­gasy nar­row-striped mon­gooses. (Good­man, et al., 1993a; Good­man, et al., 1993b)

• Known Predators

  • Barn owl (Tyto alba)
  • Madagascar long eared owl (Asio madagascariensis)
  • Malagasy cat-eye snake (Madagascarophis colubrinus)
  • Malagasy narrow-striped mongoose (Mungotictis decemlineata)

Ecosys­tem Roles

Large-eared ten­recs are spe­cial­ized ter­mites feed­ers and thus act as sec­ondary con­sumers in an ecosys­tem. The species also pro­vides feed­ing op­por­tu­ni­ties for con­sumers at higher trophic lev­els. (Good­man, et al., 1993a; Pevel­ing, et al., 2003)

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

Habi­tats pop­u­lated by large-eared ten­recs are not densely pop­u­lated by hu­mans, thus no known spe­cific eco­nomic in­flu­ence on human so­ci­eties is known. (Stephen­son, 2003)

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

Large-eared ten­recs have no known spe­cific eco­nomic in­flu­ence on human so­ci­eties.

Con­ser­va­tion Sta­tus

Large-eared ten­recs do not ap­pear to be threat­ened, but as they are de­pen­dent on for­est habi­tats, their dis­tri­b­u­tion may de­crease with in­creas­ing loss of suit­able habi­tats. Other threats are in­di­rect ef­fects due to in­creased use of pes­ti­cides. Ge­ogale au­rita is a spe­cial­ized ter­mite feeder and ter­mites are af­fected by pes­ti­cides. Thus, the po­ten­tial ef­fect on G. au­rita ap­pears high. (Stephen­son, 2003; Tin­gle, et al., 2000)

• IUCN Red List

  Least Concern
  More information

• IUCN Red List

  Least Concern
  More information

• US Federal List

  No special status

• CITES

  No special status

Other Com­ments

Ge­ogale has tra­di­tion­ally been placed in the mono­typic sub­fam­ily Ge­o­gali­nae. An African ori­gin of ten­recs is widely ac­cepted. Some au­thor­i­ties sug­gest that Ge­ogale and the other ten­recs of Mada­gas­car share a com­mon an­ces­tor, and have di­verged from one an­other after a sin­gle col­o­niza­tion of the is­land. How­ever, there is some ev­i­dence that Ge­ogale may not have arizen from the same col­o­niza­tion event that links the other ten­recs of Mada­gas­car.

Cur­rently G. au­rita is con­sid­ered the sis­ter­group of the re­main­ing ten­recs, and it is the only liv­ing de­scen­dent along its branch; the re­main­ing Mala­gasy species are de­scen­dents of the other branch.

Due to den­tal sim­i­lar­i­ties to Ge­ogale in a fos­sil found in Miocene de­posits of Kenya, this fos­sil was orig­i­nally placed in Ge­ogale. These den­tal sim­i­lar­i­ties were con­sid­ered too spe­cial­ized to give rise to the re­main­ing ten­recs, thus the an­ces­tor of Ge­ogale must have had col­o­nized Mada­gas­car in­de­pen­dently.

The iden­ti­fi­ca­tion of this fos­sil has since been dis­puted, and is now tax­o­nom­i­cally placed as Par­a­geogale. The phy­lo­ge­netic re­la­tion­ship to other mem­bers of the fam­ily Ten­re­ci­dae re­mains un­cer­tain, but mol­e­c­u­lar and mor­pho­log­i­cal ev­i­dence sug­gests a sis­ter re­la­tion­ship, thus sup­port­ing a two col­o­niza­tions hy­poth­e­sis. (Olson and Good­man, 2003; Po­duschka and Po­duschka, 1985)

Con­trib­u­tors

Thomas Nielsen (au­thor), Uni­ver­sity of Alaska Fair­banks, Link E. Olson (ed­i­tor, in­struc­tor), Uni­ver­sity of Alaska Fair­banks.

Nancy Shef­ferly (ed­i­tor), An­i­mal Di­ver­sity Web.

Ref­er­ences

Good­man, S., O. Lan­grand, C. Rax­wor­thy. 1993. Food habits of the Mada­gas­car long-eared owl Asio mada­gas­carien­sis in two habi­tats in south­ern Mada­gas­car. Os­tritch, 64: 79-85.

Good­man, S., O. Lan­grand, C. Rax­wor­thy. 1993. The food habits of the barn owl Tyto alba at three sites on Mada­gas­car. Os­tritch, 64: 160-171.

Nowak, R. 1999. Walker's Mam­mals of the World, Sixth Edi­tion. Bal­ti­more and Lon­don: The Johns Hop­kins Uni­ver­sity Press.

Olson, L., S. Good­man. 2003. Phy­logeny and bio­geog­ra­phy of ten­recs. Pp. 1235-1242 in S Good­man, J Ben­stead, eds. The Nat­ural His­tory of Mada­gas­car. Chicago and Lon­don: The Uni­ver­sity of Chicago Press.

Pevel­ing, R., A. McWilliam, P. Nagel, H. Ra­solo­manana, Ra­holi­jaona, L. Rako­to­mi­an­ina, A. Ravon­in­ja­tovo, C. De­whurst, G. Gib­son, S. Rafanomezana, C. Tin­gle. 2003. Im­pact on lo­cust con­trol on har­vester ter­mites and en­demic ver­te­brate preda­tors in Mada­gas­car. Jour­nal of Ap­plied Ecol­ogy, 40: 729-741.

Po­duschka, W., C. Po­duschka. 1985. Zur frage des gat­tungsna­mens von "<<Ge­ogale" aletris>> But­ler und Hop­wood 1957 *<<Mam­malia>>: <<In­sec­tivora>>) aus dem Miozän Ostafrikas. Zeitschrift fur Säugertierkunde, 50: 129-140.

Stephen­son, P. 2003. Lipo­ty­phla (In­sec­tivora): Ge­ogale au­rita, Large-eared Ten­rec. Pp. 1265-1267 in S Good­man, J Ben­stead, eds. The Nat­ural His­tory of Mada­gas­car. Chicago and Lon­don: The Uni­ver­sity of Chicago Press.

Tin­gle, C., J. Rother, C. De­whurst, S. Lauer, W. King. 2000. "Pes­ti­cide Ac­tion Net­work" (On-line pdf). Ac­cessed De­cem­ber 02, 2004 at http://​www.​pan-uk.​org/​briefing/​fipronil.​pdf.