Animal Diversity Web

Ge­o­graphic Range

Simias con­color (the pig-tailed lan­gur) is presently found only on the Mentawai Is­lands off the west coast of Suma­tra in In­done­sia. This species has been elim­i­nated en­tirely from some is­lands due to log­ging and hunt­ing by hu­mans. (Bur­ton, 1995; Eudey and Mem­bers of the Pri­mate Spe­cial­ist Group 2000, 2004)

• Biogeographic Regions
• oriental
  • native

• Other Geographic Terms
• island endemic

Habi­tat

The habi­tat of S. con­color in­cludes hill­sides in pri­mary forests. It is un­cer­tain whether S. con­color also re­sides in swamps and man­grove forests with dif­fer­ent sources stat­ing dif­fer­ent in­for­ma­tion re­gard­ing its pres­ence in these en­vi­ron­ments. This species is en­tirely ar­bo­real and only comes down from the trees when it is dis­turbed. (Bur­ton, 1995; Nowak, 1999)

• Habitat Regions
• tropical
• terrestrial

• Terrestrial Biomes
• rainforest

Phys­i­cal De­scrip­tion

The body length of S. con­color ranges from 490 to 550 mm in males and from 460 to 550 mm in fe­males. The av­er­age weight is around 8.7 kg for males and 7.1 kg for fe­males. The tail length of S. con­color varies be­tween 14 and 15 cm. Two color va­ri­eties exist for S. con­color, a dark grey phase and a creamy buff phase, with the dark grey phase being more com­mon. The creamy buff phase is found in roughly one in four in­di­vid­u­als. The limbs are of equal length and the tail is rather short com­pared to other pri­mate species in the sub­fam­ily Colobi­nae. Adult pig-tailed lan­gurs have black faces and small snub-noses. The coat of the dark phase of S. con­color is black­ish-brown with light speck­led hair on the nape, shoul­der, and upper back. The tail of this species is not only short, but also hair­less, ex­cept for a small amount of hair at the tail tip. (Ankel-Si­mons, 2000; Bur­ton, 1995; Noë and Bshary, 2001)

• Other Physical Features
• endothermic
• homoiothermic
• bilateral symmetry

• Sexual Dimorphism
• sexes alike

• Range mass

  7.1 to 8.7 kg

  15.64 to 19.16 lb

• Range length

  460 to 550 mm

  18.11 to 21.65 in

Re­pro­duc­tion

Males have been ob­served par­tic­i­pat­ing in dis­plays of strength that con­sist of leap­ing through the trees to at­tract mates. The so­cial group of S. con­color in­cludes one male and up to four fe­males with which the male mates. (Vogel and Win­kler, 1990; Woltan­ski, 2004)

• Mating System
• polygynous

Few data exist re­gard­ing the re­pro­duc­tive cycle of S. con­color, but it is be­lieved that a sin­gle birth oc­curs some­time dur­ing June and July. This species also ex­hibits sex­ual swelling, a trait that is rare in other Asian colobines. (Bur­ton, 1995)

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

• Average number of offspring

  1

Lit­tle is known about the parental in­vest­ment of S. con­color, but there is in­for­ma­tion about their close rel­a­tives, pro­boscis mon­keys, Nasalis lar­va­tus. Fe­male N. lar­va­tus carry, nurse, and stay close to their young for about a year. While the males do not pro­vide as much care as the fe­males, they do pro­tect their young from males from other groups. (Woltan­ski, 2004)

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

Lifes­pan/Longevity

No in­for­ma­tion is avail­able re­gard­ing the lifes­pan and longevity of S. con­color, but its rel­a­tive N. lar­va­tus lives at least 23 years in cap­tiv­ity. (Woltan­ski, 2004)

Be­hav­ior

Lit­tle is known about the be­hav­ior of S. con­color be­cause there are so few in such a lim­ited ge­o­graph­i­cal range as well as the dif­fi­culty in spot­ting them in their dense for­est habi­tat. There are two dis­tinct group types ex­hib­ited in S. con­color, fam­ily groups and groups of all males; each ex­hibit unique be­hav­iors. The most com­mon type of group­ing is the fam­ily group of one male and up to 4 fe­males. These groups can be formed with a sin­gle adult cou­ple and their young or with more than one adult fe­male with a sin­gle male. Fam­ily group mem­bers main­tain very close prox­im­ity, rarely trav­el­ing more than 5 m (16 ft.) away from one an­other. They also re­strict vocal com­mu­ni­ca­tion, only using it at des­ig­nat­ing group bound­aries and as a warn­ing to preda­tors. The all male groups ex­hibit be­hav­iors that pro­duce ex­ces­sive noise as they travel through the for­est, com­mu­ni­cate with oth­ers, and leap in dis­plays of strength. (Ankel-Si­mons, 2000; Nowak, 1999; Tilson, 1977; Vogel and Win­kler, 1990)

• Key Behaviors
• arboreal
• diurnal
• motile
• sedentary
• territorial
• social

• Range territory size

  6600 to 202000 m^2

Home Range

The size of the av­er­age S. con­color ter­ri­tory is be­tween 16.3 and 50 acres (6.5 to 20 ha). In­di­vid­u­als are not ob­served deep in­side other ter­ri­to­ries, but are seen on the mar­gin of ad­ja­cent ter­ri­to­ries. Dur­ing en­coun­ters with other groups, the males ap­proach, make loud vo­cal­iza­tions and re­turn to their home ter­ri­tory with the other group mem­bers fol­low­ing be­hind. Chas­ing and fight­ing are gen­er­ally not ob­served dur­ing these en­coun­ters. (Tilson, 1977; Vogel and Win­kler, 1990)

Com­mu­ni­ca­tion and Per­cep­tion

Com­mu­ni­ca­tion be­tween in­di­vid­u­als and groups of S. con­color is achieved by pro­duc­ing loud calls in a se­ries of vo­cal­iza­tions rang­ing from 2 to 25 nasal barks. These barks can travel at least 500 m through the rain­for­est. The pur­pose of these calls is be­lieved to be to main­tain group struc­ture and bound­aries. Males call out with loud nasal barks and fe­males reply with sharp squeals. It is also likely that chem­i­cal cues are used widely in com­mu­ni­cat­ing re­pro­duc­tive state and that vi­sion and touch are im­por­tant. (Bur­ton, 1995; Tilson, 1977)

• Communication Channels
• visual
• tactile
• acoustic
• chemical

• Perception Channels
• visual
• tactile
• acoustic
• chemical

Food Habits

This species eats leaves, fruits, and berries. Feed­ing oc­curs after sun­rise near the trees used for sleep­ing and again in the af­ter­noon. Adult males lead the for­ag­ing and the fe­males and young fol­low be­hind . (Bur­ton, 1995; Tilson, 1977)

• Primary Diet
• herbivore
  • folivore
  • frugivore

• Plant Foods
• leaves
• fruit
• flowers

Pre­da­tion

The only known enemy or preda­tor of S. con­color is man. Other large preda­tors on the Mentawai Is­lands in­clude crested ser­pent ea­gles (Spi­lor­nis cheela) and pythons (Python retic­u­la­tus), both may also prey on S. con­color. (Vogel and Win­kler, 1990; Whit­ten and Whit­ten, 1982)

• Known Predators

  • humans (Homo sapiens)

Ecosys­tem Roles

There is lit­tle avail­able in­for­ma­tion on the ecosys­tem role of the pig-tailed lan­gur. They may aid in seed dis­per­sal of trop­i­cal fruit­ing trees.

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

Pig-tailed lan­gur meat is con­sid­ered a del­i­cacy. These are im­por­tant mem­bers of the ecosys­tems in which they live, they could con­tribute to the de­vel­op­ment of the eco­tourism in­dus­try in the Mentawai is­lands. (Bur­ton, 1995)

• Positive Impacts
• food
• ecotourism

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

There are no known ad­verse af­fects of S. con­color on hu­mans.

Con­ser­va­tion Sta­tus

Pig-tailed lan­gurs are listed as an en­dan­gered species under the IUCN. The pop­u­la­tion con­sists of fewer than 10,000 in­di­vid­u­als. Habi­tat loss due to log­ging is the main cause of pop­u­la­tion de­cline. Hunt­ing is also a major prob­lem, es­pe­cially in the Pagai Is­lands be­cause S. con­color meat is con­sid­ered a del­i­cacy. This species re­ceives pro­tec­tion at the Teit­eibatti Wildlife Re­serve, lo­cated on the only is­land that pro­vides such se­cu­rity. It is be­lieved that the pop­u­la­tion size of S. con­color has de­creased by 50% dur­ing the last decade and will most likely con­tinue to drop an­other 50% dur­ing the next decade. (Bur­ton, 1995; Eudey and Mem­bers of the Pri­mate Spe­cial­ist Group 2000, 2004; Nowak, 1999)

• IUCN Red List

  Critically Endangered
  More information

• IUCN Red List

  Critically Endangered
  More information

• US Federal List

  Endangered

• CITES

  Appendix I

Other Com­ments

This species was pre­vi­ously rec­og­nized under the name Nasalis con­color.

Con­trib­u­tors

Tanya Dewey (ed­i­tor), An­i­mal Di­ver­sity Web.

Lyn­d­say Rankin (au­thor), Michi­gan State Uni­ver­sity, Bar­bara Lun­dri­gan (ed­i­tor, in­struc­tor), Michi­gan State Uni­ver­sity.

Ref­er­ences

Ankel-Si­mons, F. 2000. Pri­mate Anatomy: An In­tr­duc­tion. San Diego, Cal­i­for­nia: Aca­d­e­mic Press.

Bur­ton, F. 1995. The Mul­ti­me­dia Guide to the Non-hu­man Pri­mates. Scar­bor­ough, On­tario: Pren­tice Hall Canada.

Eudey, A., Mem­bers of the Pri­mate Spe­cial­ist Group 2000. 2004. "IUCN Red List of Threat­ened Species: Simias con­color" (On-line). Ac­cessed March 16, 2006 at http://​www.​iucnredlist.​org/​search/​details.​php?​species=20229.

Nowak, R. 1999. Pig-tailed Lan­gur. Pp. 596-597 in Walker's Mam­mals of the World, Vol. 1, 6th Edi­tion. Bal­ti­more: The Johns Hop­kins Uni­ver­sity Press.

Noë, R., R. Bshary. 2001. Colobus and Leaf Mon­keys. Pp. 380-395 in D Mac­don­ald, ed. The En­cy­clo­pe­dia of Mam­mals, Vol. 2, Re­vised Edi­tion. New York: Facts on File.

Tilson, R. 1977. So­cial or­ga­ni­za­tion of simakobu mon­keys (Nasalis con­color) in Siberut Is­land, In­done­sia. Jour­nal of Mam­mal­ogy, 58(2): 202-212.

Vogel, C., P. Win­kler. 1990. Lan­gurs and Colobi. Pp. 296-324 in S Parker, ed. Grz­imek's En­cy­clo­pe­dia of Mam­mals, Vol. 2, 1 Edi­tion. New York: Mc­Graw-Hill Pub­lish­ing Com­pany.

Whit­ten, A., J. Whit­ten. 1982. Pre­lim­i­nary ob­ser­va­tions of the Mentawai macaque on Siberut Is­land, In­done­sia. In­ter­na­tional Jour­nal of Pri­ma­tol­ogy, 3(4): 445-459.

Woltan­ski, A. 2004. "Nasalis lar­va­tus" (On-line). An­i­mal Di­ver­sity Web. Ac­cessed April 18, 2006 at http://​animaldiversity.​ummz.​umich.​edu/​site/​accounts/​information/​Nasalis_​larvatus.​html.