Animal Diversity Web

Ge­o­graphic Range

Giant ar­madil­los, Pri­odontes max­imus, range through much of the neotrop­ics. They are found from south­east­ern Venezuela and the Guianas in the north through north­east­ern Brazil, Paraguay, and the ex­treme north of Ar­gentina. Most of this species' range lies within the Ama­zon basin. (Eisen­berg and Red­ford, 1999; Par­era, 2002)

• Biogeographic Regions
• neotropical
  • native

Habi­tat

Pri­odontes max­imus is typ­i­cally found in a di­verse range of habi­tats, usu­ally in areas with a large ter­mite pop­u­la­tion. Al­though rare, they have been sighted in trop­i­cal and sub­trop­i­cal rain­for­est, sa­vanna, Brazil­ian flood­plains, and arid and semi­arid wood­lands. In these areas, the ar­madil­los have been found re­sid­ing up to 500 me­ters above sea level. (Em­mons, 1997; Par­era, 2002; Em­mons, 1997; Par­era, 2002)

• Habitat Regions
• tropical
• terrestrial

• Terrestrial Biomes
• savanna or grassland
• forest
• rainforest
• scrub forest

• Other Habitat Features
• agricultural

• Range elevation

  0 to 500 m

  0.00 to 1640.42 ft

Phys­i­cal De­scrip­tion

Pri­odontes max­imus is eas­ily dis­tin­guished from other ar­madil­los due to its enor­mous size. In most cases, it weighs up­wards of 26 kg, and mea­sures be­tween 832 and 960 mm. An­other rec­og­niz­able char­ac­ter­is­tic is its en­larged cen­tral claw, much like that of giant anteaters, Myrme­cophaga tri­dactyla. Typ­i­cal of ar­madil­los, Pri­odontes max­imus has a cara­pace cov­ered with bony scales. The dor­sal por­tion of this cara­pace ap­pears black/gray, while the ven­tral por­tions of the cara­pace are much lighter and sep­a­rated by a no­tice­able band. Un­der­neath the cara­pace, the naked body ap­pears wrinkly and pink­ish. The legs and tail are cov­ered with tough pen­tag­o­nal scales. The head is con­i­cal, with a blunt ros­trum. (Eisen­berg and Red­ford, 1999; Em­mons, 1997)

• Other Physical Features
• endothermic
• homoiothermic
• bilateral symmetry

• Sexual Dimorphism
• sexes alike

• Range mass

  18.7 to 32.3 kg

  41.19 to 71.15 lb

• Average mass

  26.8 kg

  59.03 lb

• Range length

  832 to 960 mm

  32.76 to 37.80 in

• Average length

  895.5 mm

  35.26 in

• Average basal metabolic rate

  16.892 W

  AnAge

Re­pro­duc­tion

Very lit­tle in­for­ma­tion is avail­able on the mat­ing habits of South Amer­i­can ar­madil­los. No ac­counts of the mat­ing sys­tem of P. max­imus have been pub­lished as yet. Con­sid­er­ing the habits of other ar­madil­los, how­ever, one may infer that two giant ar­madil­los pair for each breed­ing sea­son while shar­ing a bur­row. (McBee and Baker, 1982)

• Mating System
• monogamous

Very lit­tle is known about the re­pro­duc­tive be­hav­ior of giant ar­madil­los. They typ­i­cally give birth to a sin­gle off­spring (oc­ca­sion­ally two), which weigh up to 113 g at birth, and al­ready pos­sess tough skin. Wean­ing be­gins about 4 to 6 weeks after birth, and after wean­ing, the young be­come in­de­pen­dent. Ar­madil­los reach sex­ual ma­tu­rity within 9 to 12 months of birth. (Nowak, 1999; Nowak, 1999; Par­era, 2002)

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

• Breeding interval

  The breeding interval of these animals is not known.

• Breeding season

  It is not known whether these animals breed seasonally.

• Range number of offspring

  1 to 2

• Average number of offspring

  1

• Average number of offspring

  1.5

  AnAge

• Average gestation period

  4 months

• Average gestation period

  122 days

  AnAge

• Range weaning age

  4 to 5 months

• Average weaning age

  6 months

• Range time to independence

  4 to 6 months

• Range age at sexual or reproductive maturity (female)

  9 to 12 months

• Range age at sexual or reproductive maturity (male)

  9 to 12 months

Lit­tle is known about parental care in giant ar­madil­los. Moth­ers stay with the young and nurse them for 4 to 6 weeks. Af­ter­wards, the young stay with the mother until they reach in­de­pen­dence at around 6 months of age. The role of the male in parental care has not been doc­u­mented for P. max­imus. (Nowak, 1999; Par­era, 2002)

• Parental Investment
• no parental involvement
• female parental care
• pre-fertilization
  • protecting
    • female
• pre-hatching/birth
  • provisioning
    • female
  • protecting
    • female
• pre-weaning/fledging
  • provisioning
    • female
  • protecting
    • female

Lifes­pan/Longevity

The lifes­pan of these an­i­mals can reach 12 to 15 years. (Nowak, 1999)

• Typical lifespan
  Status: wild

  12 to 15 years

• Average lifespan
  Status: captivity

  4.0 years

  Max Planck Institute for Demographic Research

Be­hav­ior

Pri­odontes max­imus is largely noc­tur­nal and ter­res­trial. These ar­madil­los for­age alone, only as­sos­ci­at­ing with oth­ers to mate. They dig large bur­rows in which they rest, using their spade-like third claws. These an­i­mals are ca­pa­ble of bal­anc­ing on their hind legs and tail, al­lowign them to reach high into ter­mite mounds (this tech­nique also comes in handy for ward­ing off preda­tors). Once a mound has been erad­i­cated, an ar­madillo will bury it­self be­neath the re­mains of the mound and re­side there for a pe­riod up to 24 hours be­fore mov­ing on. It has been said that P. max­imus is also a good swim­mer. (Em­mons, 1997; Nowak, 1999; Par­era, 2002)

• Key Behaviors
• terricolous
• fossorial
• nocturnal
• motile
• nomadic
• solitary

• Range territory size

  3 (high) km^2

Home Range

The home range of P. max­imus spans 450 hectares min­i­mum, with a max­i­mum of 3 square kilo­me­ters. (Par­era, 2002)

Com­mu­ni­ca­tion and Per­cep­tion

No in­for­ma­tion ex­ists sug­gest­ing any sort of com­mu­ni­ca­tion be­tween an­i­mals. The strongest sense pos­sessed by ar­madil­los is ol­fac­tion, which could sup­port a case for the pres­ence of an ol­fac­tory com­mu­ni­ca­tion chan­nel be­tween in­di­vid­u­als. How­ever, this is merely spec­u­la­tion and has yet to be tested.

Tac­tile com­mu­ni­ca­tion un­doubt­edly oc­curs be­tween a mother and her off­spring, as well as be­tween mates. (McBee and Baker, 1982)

• Communication Channels
• tactile
• chemical

• Perception Channels
• visual
• tactile
• acoustic
• chemical

Food Habits

Giant ar­madil­los have a very spe­cial­ized diet con­sist­ing of ter­mites and cer­tain ant species. These an­i­mals roam through­out their range in search of ter­mite mounds in which to bur­row. Once they have found a mount, they com­pletely erad­i­cate it. This species has also been doc­u­mented eat­ing car­rion, worms, and other small ver­te­brates. (Em­mons, 1997; Nowak, 1999; Par­era, 2002)

• Primary Diet
• carnivore
  • insectivore

• Animal Foods
• reptiles
• carrion
• insects
• terrestrial worms

Pre­da­tion

Due to the large size and heavy shield­ing of these an­i­mals, giant ar­madil­los have few nat­ural preda­tors. Un­like other ar­madil­los, P. max­imus can­not com­pletely hide it­self within its cara­pace. They oc­ca­sion­ally fall prey to jaguars (Pan­thera onca), and pumas (Puma con­color). Hu­mans, how­ever, have had the dead­liest im­pact on the species. (Nowak, 1999; Par­era, 2002)

• Known Predators

  • mountain lions (Puma concolor)
  • jaguars (Pathera onca)

Ecosys­tem Roles

The most no­table ecosys­tem role played by P. max­imus is its con­trol over the ter­mite and ant pop­u­la­tions in a small re­gion. By keep­ing these huge pop­u­la­tions in check, the ecosys­tem can main­tain a state of equi­lib­rium, mak­ing P. max­imus some­what of a key­stone species. Also, due to its fos­so­r­ial na­ture, this species aids in soil aer­a­tion. (Em­mons, 1997; Nowak, 1999; Par­era, 2002)

• Ecosystem Impact
• soil aeration
• keystone species

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

At one point, be­fore their num­bers dwin­dled, giant ar­madil­los were key in con­trol­ling leaf­cut­ter ant pop­u­la­tions, which could reach enor­mous sizes and de­stroy crops. These an­i­mals have also been hunted by na­tives for their meat. (Em­mons, 1997)

• Positive Impacts
• food
• controls pest population

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

Al­though giant ar­madil­los can be dam­ag­ing to crops while dig­ging through soil in search of an­i­mal prey, they never di­rectly con­sume plants. (Em­mons, 1997; Par­era, 2002)

• Negative Impacts
• crop pest

Con­ser­va­tion Sta­tus

Pri­odontes max­imus is a vic­tim of habi­tat in­fringe­ment and over­hunt­ing. Many na­tive farm­ers kill the ar­madillo on sight be­cause they are thought to dam­age crops. (Em­mons, 1997; Nowak, 1999; Par­era, 2002)

• IUCN Red List

  Vulnerable
  More information

• IUCN Red List

  Vulnerable
  More information

• US Federal List

  Endangered

• CITES

  Appendix I

Con­trib­u­tors

Nancy Shef­ferly (ed­i­tor), An­i­mal Di­ver­sity Web.

David Ar­mitage (au­thor), An­i­mal Di­ver­sity Web, Phil Myers (ed­i­tor, in­struc­tor), Mu­seum of Zo­ol­ogy, Uni­ver­sity of Michi­gan-Ann Arbor.

Ref­er­ences

Eisen­berg, J., K. Red­ford. 1999. Mam­mals of the Neotrop­ics: The Cen­tral Neotripics. Vol. 3: Ecuador, Peru, Bo­livia, Brazil. Chicago & Lon­don: Uni­ver­sity of Chicago Press.

Em­mons, L. 1997. Neotrop­i­cal Rain­for­est Mam­mals. Chicago: Uni­ver­sity of Chicago Press.

Hus­son, A. 1978. The Mam­mals of Suri­name. Lei­den, The Nether­lands: E.J. Brill.

Linares, O. 1998. Mam­if­eros de Venezuela. Cara­cas: So­ciedad Con­ser­va­cionista Au­dobon De Venezuela.

McBee, K., R. Baker. 1982. Dasy­pus novem­cinc­tus. Mam­malian Species, 162: 1-9. Ac­cessed March 09, 2004 at http://​www.​science.​smith.​edu/​departments/​Biology/​VHAYSSEN/​msi/​.

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

Par­era, A. 2002. Los mam­if­eros de la Ar­gentina y la re­gion aus­tral de Su­damer­ica. Buenos Aires: El Ate­neo.