Animal Diversity Web

Ge­o­graphic Range

Pygmy tar­siers, Tar­sius pumilus, are en­demic to Cen­tral Su­lawesi, In­done­sia. (Grow and Gursky-Doyen, 2010; Musser and Dagosto, 1987)

• Biogeographic Regions
• oriental
  • native

• Other Geographic Terms
• island endemic

Habi­tat

Pygmy tar­siers in­habit mon­tane cloud forests at el­e­va­tions be­tween 1800 and 2200 m in the cen­tral Su­lawesi moun­tains. At el­e­va­tions be­tween 1900 and 2000 m, moss-cov­ered conifer for­est pre­dom­i­nates. Above this el­e­va­tion, the canopy is only 10 to 20 m high, leaves are small, tree trunks are not but­tressed, large woody vines are ab­sent, and species di­ver­sity of trees and shrubs is lower than in low­land trop­i­cal rain­for­est. Pygmy tar­siers often re­side in the lower canopy, among sapling trunks, and on the for­est floor. Upper mon­tane forests are char­ac­ter­ized by the pres­ence of dense mist. Hu­mid­ity in these re­gions is 85 to 100%, cre­at­ing a clammy, cold, and wet en­vi­ron­ment. (Grow and Gursky-Doyen, 2010; Jablon­ski, 2003; Musser and Dagosto, 1987)

• Habitat Regions
• tropical
• terrestrial

• Terrestrial Biomes
• rainforest
• mountains

• Range elevation

  1800 to 2200 m

  5905.51 to 7217.85 ft

• Average elevation

  2100 m

  6889.76 ft

Phys­i­cal De­scrip­tion

Like other tar­siers, pygmy tar­siers are small-bod­ied hap­lorhine pri­mates whose ap­pear­ance is dom­i­nated by large round eyes, large bare ears, long hind limbs with elon­gated an­kles, elon­gated dig­its, and a long slen­der tail.

Pygmy tar­siers are eas­ily dis­tin­guished from other tar­siers by their small body size, which av­er­ages ap­prox­i­mately 50 g, less than half the size of low­land tar­sier species. Their head and body length, which ranges from 80 to 111 mm is ap­prox­i­mately 75% that of other tar­siers. Pygmy tar­siers do not ex­press sex­ual di­mor­phism.

Pygmy tar­siers are si­m­il­iar in over­all ap­pear­ance to spec­tral tar­siers, of which they were once con­sid­ered a sub­species. The pelage of pygmy tar­siers is silky and is longer and denser than that of spec­tral tar­siers. They are red-brown in color, al­though pygmy tar­siers oc­ca­sion­ally lack the buff col­ored post-au­ric­u­lar spot com­mon among spec­tral tar­siers. The un­der­belly of pygmy tar­siers is buff, gray­ish, or slate col­ored. Hair on the face is usu­ally shorter than hair on the rest of the body.

Pygmy tar­siers have a rounded head with a short snout. Their ears are rel­a­tively smaller than those of other tar­siers, and the de­gree of or­bital en­large­ment is smaller than other species. Their eyes are ap­prox­i­mately 16 mm in di­am­e­ter.

Mem­bers of this species have a long slen­der tail. Ap­prox­i­mately one third of the ven­tral sur­face of the tail is scaly, which is at­trib­uted to its func­tion in body pos­ture. The tail is heav­ily haired and is dark brown or black in color. The tip of the tail bears a tuft of hair.

Pygmy tar­siers, like, spec­tral tar­siers, have short fore limbs and small hands, sug­gest­ing that these an­i­mals use their hands more for lo­co­mo­tion than for im­mo­bi­liz­ing prey, as do other tar­sier species. Pygmy tar­siers have sev­eral dis­tinc­tive mor­pho­log­i­cal char­ac­ter­is­tics that may stem from their unique high­land habi­tat. Their body pro­por­tions dif­fer con­sid­er­ably from low­land tar­siers. Pygmy tar­siers have a longer tail rel­a­tive to head-body length and longer thighs rel­a­tive to over­all hind limb length, De­spite their smaller over­all size, ab­solute thigh length is still com­pa­ra­ble to that of other Su­lawe­sian tar­siers. These qual­i­ties are ad­van­ta­geous for leap­ing great dis­tances be­tween trees in thin for­est cover. The small size of pygmy tar­siers may be an adap­ta­tion to the cooler, less pro­duc­tive high­land en­vi­ron­ment. Al­though most tar­siers have low basal meta­bolic rates, pygmy tar­siers may have in­creased meta­bolic rates due to their small size and cold habi­tat.

Al­though most tar­siers have re­duced nails that do not ex­tend past the dig­i­tal pads, pygmy tar­siers have nails on all five dig­its of the hand, in­clud­ing the hal­lux, and on the two lat­eral dig­its of the foot. These nails ex­tend be­yond the edge of the dig­i­tal pads, are lat­er­ally com­pressed, and are sharply pointed at the tips, re­sem­bling claws. The dig­i­tal pads on both their hands and feet are re­duced in size. Both their claw-like nails and re­duced pads are thought to pro­vide a bet­ter grasp on the mossy sub­strate to which they cling dur­ing feed­ing and lo­co­mo­tion. (Groves and Shekelle, 2010; Grow and Gursky-Doyen, 2010; Musser and Dagosto, 1987; Niemitz, 1984; Nowak, 1999; Schwartz, 2003)

• Other Physical Features
• endothermic
• bilateral symmetry

• Sexual Dimorphism
• sexes alike

• Range mass

  48 to 52 g

  1.69 to 1.83 oz

• Range length

  80 to 111 mm

  3.15 to 4.37 in

• Average length

  96 mm

  3.78 in

Re­pro­duc­tion

Be­cause they are in­fre­quently ob­served and until re­cently were con­sid­ered a sub­species of spec­tral tar­siers (Tar­sius tar­sier), lit­tle is known re­gard­ing the mat­ing sys­tems of pygmy tar­siers. Spec­tral tar­siers, their clos­est ge­o­graphic neigh­bor and a mem­ber of the genus, are typ­i­cally monog­a­mous, al­though some so­cial groups con­sis­tently ex­hibit polyg­yny. (Grow and Gursky-Doyen, 2010; Gursky-Doyen, 2010)

Al­though lit­tle is known re­gard­ing the re­pro­duc­tive be­hav­ior of pygmy tar­siers, it likely re­sem­bles that of other tar­siers. Spec­tral tar­siers have two breed­ing sea­sons an­nu­ally, spaced 6 months apart. One breed­ing sea­son oc­curs at the be­gin­ning of the rainy sea­son, and the other oc­curs at the end of the rainy sea­son. Births in spec­tral tar­siers occur in May and from No­vem­ber to De­cem­ber.

Pygmy tar­siers likely have a long ges­ta­tion pe­riod of around 6 months and pro­duce only one off­spring per year. Ges­ta­tion of Philip­pine tar­siers lasts 178 days, after which time a fully furred, well-de­vel­oped off­spring is born. Young cling to the mother's ven­trum or are car­ried in the mouth. Philip­pine tar­siers are pre­co­cial, and off­spring are soon able to fol­low their kin. They can leap at about 1 month of age and can cap­ture prey at ap­prox­i­mately 42 days of age. Wean­ing is thought to occur shortly af­ter­ward. Pre­na­tal de­vel­op­ment is in­cred­i­bly slow in west­ern tar­siers, and, as such, neonates are born with ap­prox­i­mately 60 to 70% of the brain mass and 20% of the body mass of an adult. New­born spec­tral tar­siers have sim­i­larly high in­fant-to-adult weight ra­tios of 20 to 33%. Fe­male west­ern tar­siers can first con­ceive around 2 years of age in cap­tiv­ity. (Fitch-Sny­der, 2003; Grow and Gursky-Doyen, 2010; Gursky, 2000; Musser and Dagosto, 1987; Nowak, 1999; Schwartz, 2003)

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

Lit­tle is known re­gard­ing parental in­vest­ment of pygmy tar­siers. In closely re­lated spec­tral tar­siers, parental care is pri­mar­ily ma­ter­nal. Some al­lo­care is ex­hib­ited by subadult fe­males, and much less so by adult and subadult males, but this is ex­tremely lim­ited com­pared to that dis­played by some platyrrhine pri­mates. Philip­pine tar­siers are born well-de­vel­oped, and young cling to their mother's belly. Moth­ers nurse their young and may also carry young in their mouth. Young spec­tral tar­siers ma­ture quickly; they can travel in groups 23 days after birth and are able to hunt alone after 42 days. Young fe­males re­main with their par­ents until adult­hood, whereas young males leave their natal group as ju­ve­niles. (Gursky, 2000; Musser and Dagosto, 1987; Nowak, 1999)

• Parental Investment
• precocial
• male parental care
• female parental care
• pre-hatching/birth
  • provisioning
    • female
  • protecting
    • female
• pre-weaning/fledging
  • provisioning
    • female

Lifes­pan/Longevity

Lit­tle in­for­ma­tion is avail­able re­gard­ing longevity of pygmy tar­siers. The old­est wild-caught tar­sier con­tin­ued to live in cap­tiv­ity until 12 years, 5 months of age (a male Tar­sius syrichta). Record lifes­pans of cap­tive-bred tar­siers are 11 years, 10 months (a male Tar­sius syrichta) and over 13 years (a fe­male Tar­sius ban­canus).

Be­hav­ior

Tar­siers are noc­tur­nal or cre­pus­cu­lar and mainly ar­bo­real. In the dense veg­e­ta­tion of their habi­tat, pygmy tar­siers spend most of the day sleep­ing on ver­ti­cal branches or pos­si­bly in hol­low trees. When cling­ing to a ver­ti­cal branch, they often use their tail to brace them­selves against the ver­ti­cal sup­port and to sup­port their body. The head of pygmy tar­siers tends to drop down­ward be­tween the shoul­ders when sleep­ing. If dis­turbed while rest­ing, these an­i­mals may move up and down the ver­ti­cal sup­port with the face pre­sented to­wards the threat, mouth open, and teeth bared. When wak­ing, pygmy tar­siers con­tin­u­ously furl or crin­kle their ears.

Tar­siers spend much of their time scan­ning for prey from low po­si­tions on tree trunks. Al­though they do not build nests, they may re­turn to the same tree to sleep. Pre­ferred sleep­ing trees are large, and scarcity of large trees at high al­ti­tudes may re­strict the num­ber of pos­si­ble sleep­ing sites for this species.

Pygmy tar­siers have a wide field of vi­sion and can ro­tate their head nearly 360 de­grees. They can leap sev­eral me­ters from tree to tree, and their leaps tend to be frog­like. On a flat sur­face, they can leap from 1.2 to 1.7 m long and up to 0.6 m high. When leap­ing, their tail is arched over their back. When walk­ing on all fours, how­ever, the tail hangs down.

Only one group of pygmy tar­siers has been ob­served in the wild. This group con­sisted of 1 adult fe­male and 2 adult males, which is un­usual for Tar­sius. Low­land Su­lawe­sian tar­siers usu­ally live in fam­ily groups of 1 adult male, 1 to 2 adult fe­males, and off­spring, though group size varies with re­source avail­abil­ity and other eco­log­i­cal fac­tors. So­cial group com­po­si­tion of pygmy tar­siers may be a re­sult of eco­log­i­cal con­straints unique to their high-al­ti­tude habi­tat, which al­ters the dy­nam­ics of group liv­ing. The pop­u­la­tion den­sity of pygmy tar­siers also ap­pears to be much lower than that of other tar­siers, as in­di­cated by the his­tor­i­cal dif­fi­culty in find­ing in­di­vid­u­als to con­firm the con­tin­ued ex­is­tence of the species. A 3-month sur­vey found only 3 in­di­vid­u­als in 60 nights of at­tempted trap­ping, whereas in an­other 3-month sur­vey, 100 spec­tral tar­siers were recorded.

Spec­tral tar­siers, and pos­si­bly pygmy tar­siers, are ter­ri­to­r­ial. Spec­tral tar­siers ac­tively chase oth­ers out of their home range and mark their core areas by rub­bing the branches with urine and epi­gas­tric glands. (Groves and Shekelle, 2010; Jablon­ski, 2003; Musser and Dagosto, 1987; Nowak, 1999)

• Key Behaviors
• arboreal
• scansorial
• saltatorial
• nocturnal
• crepuscular
• motile
• territorial
• social

• Range territory size

  12000 (low) m^2

Home Range

Lit­tle is known re­gard­ing the home range of pygmy tar­siers. Fe­male pygmy tar­siers have a home range of at least 1.2 ha. Males and fe­males ex­hibit dif­fer­ent pat­terns of travel, and males are dif­fi­cult to track. (Groves and Shekelle, 2010)

Com­mu­ni­ca­tion and Per­cep­tion

Tar­siers com­monly com­mu­ni­cate through vo­cal­iza­tions and urine scent mark­ing. How­ever, each of these is ob­served much less fre­quently among pygmy tar­siers than other species. The in­fre­quency of ob­served scent mark­ing in this species, how­ever, may be due to dif­fi­culty in mon­i­tor­ing canopy habi­tat and high rain­fall quickly wash­ing away urine.

The au­di­tory bul­lae of pygmy tar­siers are more en­larged than those of other tar­siers, per­haps be­cause the heavy fog and thick moss cover com­mon in their habi­tat tend to re­duce sound travel. How­ever, vocal com­mu­ni­ca­tion is markedly re­duced in pygmy tar­siers. They rarely per­form the male-fe­male vocal duets or fam­ily cho­ruses typ­i­cal of low­land species. Be­cause these vo­cal­iza­tions are as­so­ci­ated with ter­ri­tory main­te­nance, this could in­di­cate that pygmy tar­siers are less ter­ri­to­r­ial than low­land species, or that they make use other means of com­mu­ni­ca­tion to com­mu­ni­ca­tion the same in­for­ma­tion.

The eye of tar­siers is unique among pri­mates and is largely re­spon­si­ble for tar­sier sur­vival. Lack­ing a tape­tum lu­cidum, the eyes of tar­siers are greatly en­larged to allow night vi­sion. The av­er­age vol­ume of their eyes is equal to the av­er­age tar­sier cra­nial ca­pac­ity. Be­cause their eyes are im­mo­bile within the or­bits, tar­siers ad­just their vi­sion by mov­ing their head, which can ro­tate through nearly 180 de­grees in ei­ther di­rec­tion. The ex­tent to which tar­siers use vi­sual sig­nals, such as pos­tures and dis­plays, is not known

In all pri­mate species tac­tile com­mu­ni­ca­tion is im­por­tant be­tween moth­ers and their off­spring, as well as be­tween mates. (Groves and Shekelle, 2010; Grow and Gursky-Doyen, 2010; Musser and Dagosto, 1987; Nowak, 1999; Schwartz, 2003)

• Communication Channels
• tactile
• acoustic
• chemical

• Other Communication Modes
• duets
• choruses
• scent marks

• Perception Channels
• visual
• tactile
• acoustic
• chemical

Food Habits

Tar­siers are the only pri­mates that are to­tally car­niv­o­rous. Pygmy tar­siers are in­sec­tiv­o­rous and eat pri­mar­ily arthro­pods with heav­ily ker­a­tinized ex­oskele­tons. Larger arthro­pods are less abun­dant at higher al­ti­tudes. Pygmy tar­siers also com­monly prey upon small ver­te­brates.

Tar­siers hunt by leap­ing from tree trunks and pounc­ing on ter­res­trial prey. They kill prey by bit­ing down with the an­te­rior teeth, and they chew with a side to side mo­tion. Tar­siers typ­i­cally take large prey for their body size and con­sume the en­tire prey, which can re­sult in large fluc­tu­a­tions in body weight. Pygmy tar­siers drink water by lap­ping. (Grow and Gursky-Doyen, 2010; Musser and Dagosto, 1987; Nowak, 1999; Schwartz, 2003)

• Primary Diet
• carnivore
  • insectivore
  • eats non-insect arthropods

• Animal Foods
• birds
• mammals
• amphibians
• reptiles
• insects
• aquatic crustaceans

Pre­da­tion

De­spite the rar­ity of alarm calls, pre­da­tion is a con­sid­er­able threat to pygmy tar­siers. Most com­mon preda­tors are di­ur­nal rap­tors, the main birds of prey in Su­lawesi. The open canopy cover of the high­land mon­tane forests makes this species es­pe­cially vul­ner­a­ble to rap­tor at­tacks. (Grow and Gursky-Doyen, 2010; Musser and Dagosto, 1987)

Ecosys­tem Roles

Pygmy tar­siers con­sume a large va­ri­ety of arthro­pods and small ver­te­brates, and they are preyed upon by di­ur­nal rap­tors. Tar­siers also act as hosts to a num­ber of ecto- and en­dopar­a­sites. (Brack and Niemitz, 1984; Grow and Gursky-Doyen, 2010; Jablon­ski, 2003)

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

There are no known di­rect pos­i­tive ef­fects of pygmy tar­siers on hu­mans. (Grow and Gursky-Doyen, 2010; Musser and Dagosto, 1987)

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

There are no known ad­verse ef­fects of pygmy tar­siers on hu­mans.

Con­ser­va­tion Sta­tus

Be­cause they are only known from a few mu­seum spec­i­mens and one wild group, the IUCN lists pygmy tar­siers as "Data De­fi­cient." How­ever, pop­u­la­tions are small, frag­mented and de­clin­ing, and this species could eas­ily be­come en­dan­gered. De­for­esta­tion is a threat, al­though their re­mote habi­tat, which has thus far seen only small-scale human ex­pan­sion, may place this species at lesser risk.

The CITES treaty on the in­ter­na­tional trade in wildlife in­cludes all tar­siers in Ap­pen­dix II, lim­it­ing in­ter­na­tional trade. (Grow and Gursky-Doyen, 2010; Musser and Dagosto, 1987; Nowak, 1999; Shekelle and Salim, 2008; Wright, 2003)

• IUCN Red List

  Data Deficient
  More information

• IUCN Red List

  Data Deficient
  More information

• US Federal List

  No special status

• CITES

  Appendix II

Other Com­ments

Tar­sius pumilus was first de­scribed by Miller and Hol­lis­ter in 1921 but was often sub­se­quently treated as a sub­species of Tar­sius tar­sier. It is now rec­og­nized as a sep­a­rate species. (Musser and Dagosto, 1987)

Con­trib­u­tors

Trevor Ford (au­thor), Yale Uni­ver­sity, Eric Sar­gis (ed­i­tor), Yale Uni­ver­sity, Gail Mc­Cormick (ed­i­tor), An­i­mal Di­ver­sity Web Staff.

Ref­er­ences

Brack, M., C. Niemitz. 1984. The par­a­sites of wild-caught tar­siers (Tar­sius ban­canus). Pp. 77-84 in C Niemitz, ed. Bi­ol­ogy of Tar­siers. New York: Gus­tav Fis­cher Ver­lag.

Cas­ten­holz, A. 1984. The eye of Tar­sius. Pp. 303-318 in C Niemitz, ed. Bi­ol­ogy of Tar­siers. New York: Gus­tav Fis­cher Ver­lag.

Fitch-Sny­der, H. 2003. His­tory of Cap­tive Con­ser­va­tion of Tar­siers. Pp. 277-295 in P Wright, E Si­mons, S Gursky, eds. Tar­siers: Past, Pre­sent and Fu­ture. New Brunswick: Rut­gers Uni­ver­sity Press.

Groves, C., M. Shekelle. 2010. The Gen­era and Species of Tar­si­idae. In­ter­na­tional Jour­nal of Pri­ma­tol­ogy, 31: 1071-1082.

Grow, N., S. Gursky-Doyen. 2010. Pre­lim­i­nary Data on the Be­hav­ior, Ecol­ogy, and Mor­phol­ogy of Pygmy Tar­siers (Tar­sius pumilus). In­ter­na­tional Jour­nal of Pri­ma­tol­ogy, 31: 1174-1191.

Gursky-Doyen, S. 2010. In­traspe­cific Vari­a­tion in the Mat­ing Sys­tem of Spec­tral Tar­siers. In­ter­na­tional Jour­nal of Pri­ma­tol­ogy, 31: 1161-1173.

Gursky, S. 2000. Al­lo­care in a Noc­tur­nal Pri­mate: Data on the Spec­tral Tar­sier, Tar­sius spec­trum. Folia Pri­ma­to­log­ica, 71: 39-54.

Jablon­ski, N. 2003. The Evo­lu­tion of the Tar­siid Niche. Pp. 35-49 in P Wright, E Si­mons, S Gursky, eds. Tar­siers: Past, Pre­sent, and Fu­ture. New Brunswick: Rut­gers Uni­ver­sity Press.

Musser, G., M. Dagosto. 1987. The Iden­tity of Tar­sius pumilus, a Pygmy Species En­demic to the Mon­tane Mossy Forests of Cen­tral Su­lawesi. Amer­i­can Mu­seum Novi­tates, 2867: 1-53. Ac­cessed May 17, 2011 at http://​digitallibrary.​amnh.​org/​dspace/​handle/​2246/​5204.

Niemitz, C. 1984. Tax­on­omy and dis­tri­b­u­tion of the genus Tar­sius Storr, 1780. Pp. 1-16 in Bi­ol­ogy of Tar­siers. New York: Gus­tav Fis­cher Ver­lag.

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

Schwartz, J. 2003. How Close Are the Sim­i­lar­i­ties be­tween Tar­siers and Other Pri­mates?. Pp. 50-96 in P Wright, E Si­mons, S Gursky, eds. Tar­sier: Past, Pre­sent, and Fu­ture. New Brunswick: Rut­gers Uni­ver­sity Press.

Shekelle, M., A. Salim. 2008. "Tar­sius pumilus" (On-line). In: IUCN 2010. IUCN Red List of Threat­ened Species. Ver­sion 2010.4. Ac­cessed May 08, 2011 at http://​www.​iucnredlist.​org/​apps/​redlist/​details/​21490/​0.

Wright, P. 2003. Are Tar­siers Silently Leap­ing into Ex­tinc­tion?. Pp. 296-308 in P Wright, E Si­mons, S Gursky, eds. Tar­siers: Past, Pre­sent, and Fu­ture. New Brunswick: Rut­gers Uni­ver­sity Press.