Animal Diversity Web

Ge­o­graphic Range

Co­querel’s sifakas (Pro­p­ithe­cus co­quereli) are en­demic to Mada­gas­car. This species re­sides in dry de­cid­u­ous forests found to the north and east of the Bet­si­boka River. It has been re­ported as far north as Bealanana, as far south as Am­bato-Boeni, and to the east in the vicin­ity of An­tetemasy. It can be found in Ankarafantsika Na­tional Park as well as the Bora Spe­cial Re­serve. Doc­u­mented sight­ings have oc­curred in the coastal man­groves of Baie de Ma­ha­jamba. ("Co­querel's Sifaka", 2011; "Pro­p­ithe­cus co­quereli", 2008; Pas­torini, et al., 2001; Rako­toarisoa, et al., 2006)

• Biogeographic Regions
• ethiopian
  • native

• Other Geographic Terms
• island endemic

Habi­tat

Co­querel’s sifaka in­habit old growth and sec­ondary growth forests of mixed de­cid­u­ous and ever­green trees, from sea level to 300 m above sea level. They also travel through scrub habi­tat when trav­el­ing be­tween frag­mented for­est patches. ("Co­querel's Sifaka", 2011; "Pro­p­ithe­cus co­quereli", 2008)

• Habitat Regions
• tropical
• terrestrial

• Terrestrial Biomes
• forest
• rainforest
• scrub forest

• Range elevation

  0 to 300 m

  0.00 to 984.25 ft

Phys­i­cal De­scrip­tion

Co­querel’s sifakas have dor­sal pelage and limbs that are pre­dom­i­nately white. They have large choco­late-brown mark­ings on the front of the arms, thighs and chest, which may dif­fer slightly in size and place­ment. The fur is quite dense. The back may be a pale sil­ver-gray or brown, while the tail ranges in color from sil­ver-gray to white. Short white hairs cover the muz­zle and the face is black. They have small, black ears that pro­trude through the sur­round­ing fur. Males can be dif­fer­en­ti­ated from fe­males by their gular (throat) gland, which stains the sur­round­ing skin and hair, as well as the dark red-brown color of the pe­ri­anal skin. Co­querel’s sifaka range in mass from 3.7 to 4.3 kg. ("Co­querel's Sifaka", 2011; Jolly, 1966; Kap­peler, 1991; Pas­torini, et al., 2001; Rako­toarisoa, et al., 2006; Richard, 2003; Tat­ter­sall, 1982)

• Other Physical Features
• endothermic
• homoiothermic
• bilateral symmetry

• Sexual Dimorphism
• sexes colored or patterned differently

• Range mass

  3.7 to 4.3 kg

  8.15 to 9.47 lb

Re­pro­duc­tion

Co­querel’s sifakas have syn­chro­nized es­trous which oc­curs dur­ing Jan­u­ary and Feb­ru­ary. Exact tim­ing can be pre­dicted from the two day flush­ing of the vulva found in fe­males in the pre­cop­u­la­tory pe­riod. Fe­males mate with in­tra­group males or males from vis­it­ing groups. They ap­pear to be polyan­drous, which may serve to con­fuse pa­ter­nity and im­pede male in­fan­ti­cide. Males have been wit­nessed fight­ing over ac­cess to es­trous fe­males, how­ever, the vic­tor isn't al­ways cho­sen to mate. Co­querel’s sifakas ap­pear to con­tinue re­pro­duc­ing re­gard­less of senes­cence. The old­est re­pro­duc­ing in­di­vid­ual on record was 24 years old, and an­i­mals have been known to re­pro­duce the year they die. (Bas­t­ian and Brock­man, 2007; "Co­querel's Sifaka", 2011; Grieser, 1992; "Pro­p­ithe­cus co­quereli", 2008; Jolly, 1966; Kap­peler, 1991; Richard, 1978; Richard, 2003; Tay­lor, 2008)

• Mating System
• polyandrous

Ges­ta­tion in Co­querel’s sifakas lasts for ap­prox­i­mately 162 days. Typ­i­cally, a sin­gle in­fant is born dur­ing the dry sea­son, which oc­curs dur­ing June and July. New­borns weigh be­tween 85 and 115 g at birth, with an av­er­age weight of 100 g. In­fants cling to the mother's ven­ter dur­ing travel until they are about 1 month old, at which point they move to the dor­sum. In­fants are weaned dur­ing the wet sea­son at ap­prox­i­mately 5 to 6 months of age and are com­pletely in­de­pen­dent after 6 months. Most in­di­vid­u­als reach adult size in 1 to 5 years, de­pend­ing on habi­tat con­di­tions and for­age avail­abil­ity. Es­ti­mated age of sex­ual ma­tu­rity for both males and fe­males is re­port­edly 2 to 3.5 years of age. Fe­males have been known to give birth for the first time at 3 years of age, while oth­ers have oth­ers have been re­ported to have their first off­spring at the age of 6. Hy­bridiza­tions can occur be­tween closely re­lated species such as Pro­p­ithe­cus ver­reauxi, which was once con­sid­ered a sub­species of Co­querel’s sifakas. (Bas­t­ian and Brock­man, 2007; "Co­querel's Sifaka", 2011; Grieser, 1992; "Pro­p­ithe­cus co­quereli", 2008; Jolly, 1966; Kap­peler, 1991; Richard, 1978; Richard, 2003; Tay­lor, 2008)

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

• Breeding interval

  Propithecus coquereli breeds once yearly.

• Breeding season

  Propithecus coquereli breeds during January and February.

• Average number of offspring

  1

• Average gestation period

  162 days

• Range weaning age

  5 to 6 months

• Average time to independence

  6 months

• Range age at sexual or reproductive maturity (female)

  2 to 6 years

• Average age at sexual or reproductive maturity (female)

  3.5 years

• Range age at sexual or reproductive maturity (male)

  2 (low) years

• Average age at sexual or reproductive maturity (male)

  3.5 years

Co­querel's sifakas have a max­i­mum of 2 off­spring per group per year, pre­sum­ably due to the high costs of re­pro­duc­tion. Fe­males give birth every other year and must in­crease their basal meta­bolic rate be­fore and dur­ing par­tu­ri­tion. As with most mam­mals, the most en­er­get­i­cally ex­pen­sive as­pect of re­pro­duc­tion is lac­ta­tion, which oc­curs dur­ing the dry sea­son and lasts for 5 to 6 months. Al­though rare, males and ju­ve­niles have been ob­served car­ry­ing in­fants. In­for­ma­tion on pa­ter­nal care is lim­ited, how­ever, the high­est rank­ing male in the group of­fers lim­ited sup­port to fe­males and their young. (Bas­t­ian and Brock­man, 2007; "Co­querel's Sifaka", 2011; Grieser, 1992; "Pro­p­ithe­cus co­quereli", 2008; Jolly, 1966; Kap­peler, 1991; Richard, 1978; Richard, 2003; Tay­lor, 2008)

• Parental Investment
• altricial
• female parental care
• pre-weaning/fledging
  • provisioning
    • female
  • protecting
    • male
    • female
• extended period of juvenile learning

Lifes­pan/Longevity

In the wild, Co­querel's sifakas live be­tween 27 and 30 years. The old­est known in­di­vid­ual in the wild was 30 years old. In cap­tiv­ity, they live be­tween 25 and 30 years, and the old­est known cap­tive in­di­vid­ual, held at the Duke Lemur Cen­ter, lived to be 31 years old. ("Co­querel's Sifaka", 2011; Richard, 2003; Tay­lor, 2008)

• Range lifespan
  Status: wild

  30 (high) years

• Range lifespan
  Status: captivity

  31 (high) years

• Typical lifespan
  Status: wild

  30 (high) years

• Average lifespan
  Status: wild

  27 years

• Typical lifespan
  Status: captivity

  25 to 30 years

Be­hav­ior

Co­querel’s sifakas are di­ur­nal and live in groups rang­ing from 3 to 10 in­di­vid­u­als. They are mainly ar­bo­real and maintin a ver­ti­cal pos­ture while using the back legs to leap more than 6 m in a sin­gle bound. Their pri­mary mode of lo­co­mo­tion is com­monly re­ferred to as “ver­ti­cal cling­ing and leap­ing”. At rest, the body is held ver­ti­cally pressed to a tree trunk or branch. Oc­ca­sion­ally, they de­scend from the canopy to move be­tween for­est frag­ments or to ob­tain fallen food. When on the ground, they hop bipedally with their long arms held out for bal­ance. Allo-groom­ing plays an im­por­tant role in de­vel­op­ing and main­tain­ing so­cial re­la­tion­ships and in­tra­group hi­er­ar­chies. Play is often seen dur­ing the wet sea­son. ("Co­querel's Sifaka", 2011; "Pro­p­ithe­cus co­quereli", 2008; Kubzdela, et al., 1992; Richard, 1978; Richard, 2003; Tay­lor, 2008)

Co­querel’s sifakas are ma­tri­ar­chal. Fe­males com­monly re­main with their natal group while males are forced to dis­perse upon reach­ing ma­tu­rity. Males often switch groups, and it is un­com­mon for them to stay with a sin­gle group for more than 8 years. Oc­ca­sion­ally, fe­males leave their natal group, how­ever, this only oc­curs if there are large num­ber of un­mated adult fe­males. Fe­males are gen­er­ally dom­i­nant to males and may use ag­gres­sion to se­cure pre­ferred for­age or to reg­u­late sex­ual ad­mit­tance. If males do not obey, fe­males may lunge, smack or bite the back of the neck or limbs. Male sub­mis­sion is ex­hib­ited via pos­tur­ing, which in­cludes cow­er­ing, rolling his tail be­tween his legs, bar­ing teeth in a gri­mace, or leap­ing out of the fe­males way. Males may also ex­hibit sub­mis­sion through vo­cal­iza­tions, which pri­mar­ily in­cludes soft calls. Group mem­ber­ship and fe­male dom­i­nance does not ap­pear to di­min­ish with age. ("Co­querel's Sifaka", 2011; "Pro­p­ithe­cus co­quereli", 2008; Kubzdela, et al., 1992; Richard, 1978; Richard, 2003; Tay­lor, 2008)

• Key Behaviors
• arboreal
• saltatorial
• diurnal
• motile
• territorial
• social
• dominance hierarchies

• Range territory size

  40000 to 90000 m^2

Home Range

Co­querel's sifakas have home ranges be­tween 40,000 and 90,000 m^2, with a core ter­ri­tory of 20,000 to 30,000 m^2. Core ter­ri­to­ries are used about 60% of the time. ("Pro­p­ithe­cus co­quereli", 2008; Richard, 1978; Richard, 2003)

Com­mu­ni­ca­tion and Per­cep­tion

Co­querel’s sifakas en­gage in au­di­tory, vi­sual and ol­fac­tory com­mu­ni­ca­tion. Alarm calls used for aer­ial preda­tors are often de­scribed as roar­ing barks and growls. Gen­eral alarm calls, which sound like "sifaka" with an ex­plo­sive click­ing sound at the end, are used to alert group mem­bers of ter­res­trial preda­tors. When sep­a­rated from their group, Co­querel's sifakas emit a loud, ex­tended wail. Fa­cial ex­pres­sions and body pos­tures in­clude a play face where the mouth is held open in a silent laugh, and head jerks where the head is thrown quickly back while call­ing when fac­ing a preda­tor. Poly­mor­phic trichro­macy, which al­lows them to see a full range of col­ors, was re­cently dis­cov­ered in Co­querel’s sifaka. Both males and fe­males use of the anogen­i­tal re­gion, the area be­tween the anus and the gen­i­tala, for scent mark­ing. Males also use the gular gland for scent mark­ing branches and tree trunks. Both males and fe­males scant mark with urine as well. Males touch the end of the penis to a tree trunk while cling­ing to it and move up the trunk about 50 cm leav­ing a line of urine. Ver­ti­cal trunk mark­ing is less com­mon in fe­males; how­ever, they may press their body to the tree trunk while they climb a short ways up to leave a sim­i­lar mark as males. The mark­ings are thought to dis­play sex of the marker as well as re­pro­duc­tive sta­tus of fe­males since mark­ings greatly in­crease in fre­quency dur­ing mat­ing sea­son. (Fich­tel and P. van Schaik, 2006; Hayes, et al., 2005; Jolly, 1966; Richard, 2003; Veilleux and Bol­nick, 2009)

• Communication Channels
• visual
• tactile
• acoustic
• chemical

• Other Communication Modes
• scent marks

• Perception Channels
• visual
• tactile
• acoustic
• chemical

Food Habits

Co­querel’s sifaka eats im­ma­ture and ma­ture leaves, seeds, flow­ers, fruit and bark. The ma­jor­ity of their diet con­sists of leaves, and their teeth are well-adapted for slic­ing and grind­ing plant ma­te­r­ial. Their total diet in­cludes 75 to 100 dif­fer­ent plant species; how­ever, 60 to 80% of the time they feed on only 10% of these species. It has been sug­gested that Co­querel’s sifakas are op­por­tunis­tic feed­ers as dom­i­nant for­age plants change with sea­son. Their en­larged cecum and colon helps fa­cil­i­tate di­ges­tion of their highly fi­brous diet. Undi­gested beans have been found in feces, and it has been pro­posed that nour­ish­ment is ob­tained from the cas­ing rather than the bean it­self. Cap­tive in­di­vid­u­als at the Duke Lemur Cen­ter are pri­mar­ily fed shin­ing leaf sumac and mi­mosa. Be­tween 30 to 40% of the day is spent for­ag­ing, with peak for­ag­ing ac­tiv­ity oc­cur­ring dur­ing morn­ing, mid­day, and late-af­ter­noon. For­ag­ing bouts are sep­a­rated by rest, and when for­ag­ing, they re­main within their ter­ri­to­ries and spend the ma­jor­ity of the time within a core area. The ma­jor­ity of ag­gres­sion found be­tween sexes is re­lated to feed­ing. Fe­males com­monly ex­hibit dom­i­nance dur­ing for­ag­ing bouts. Fe­male dom­i­nance dur­ing feed­ing likely plays an im­por­tant role dur­ing ges­ta­tion and lac­ta­tion. Fe­males usu­ally ex­er­cise dom­i­nance by con­trol­ling ac­cess to pre­ferred food or feed­ing areas by being the first to feed or feed­ing until sat­is­fied and then al­low­ing males to ac­cess the food (Camp­bell, et al., 2001; "Co­querel's Sifaka", 2011; Hayes, et al., 2005; Jolly, 1966; Kubzdela, et al., 1992; Richard, 1978; Richard, 2003)

• Primary Diet
• herbivore
  • folivore

• Plant Foods
• leaves
• wood, bark, or stems
• seeds, grains, and nuts
• flowers

Pre­da­tion

Co­querel’s sifakas are preyed upon by hawks and other rap­tors, con­stric­tor snakes as well as the puma-like fossa, the largest mam­malian car­ni­vore found on Mada­gas­car. Aer­ial preda­tors would be of most dan­ger to the in­fants. In­tro­duced preda­tors in­clude feral dogs, African wild­cats, Eu­ro­pean wild­cats, large In­dian civets and Egypt­ian mon­gooses. The most im­mi­nent threat to Co­querel’s sifakas is hu­mans, which hunt them for food and sport. In the past, the Mala­gasy peo­ple did not hunt sifakas be­cause it was con­sid­ered “fady” or taboo; how­ever, there are re­ports that hunger is over­pow­er­ing this cus­tom. Pop­u­la­tions of Co­querel's sifakas that have been hunted in the past flee from hu­mans; if not, they may give a gen­eral alarm call. Nu­mer­ous re­ports de­scribe being ap­proached by a group of Co­querel’s sifakas on the ground. All mem­bers of the group give alarm calls and head jerks while ap­proach­ing hu­mans. One re­port doc­u­mented a group com­ing within 3 to 5 m. Be­tween alarm calls, they were said to stare and weave their heads back and forth. Roar­ing barks are made for aer­ial preda­tors and "sifaka" calls are made for ter­res­trial preda­tors. Neigh­bor­ing groups often re­turn alarm calls after search­ing the local area for po­ten­tial preda­tors. (But­ler, 2008; Fich­tel and P. van Schaik, 2006; Jolly, 1966; Richard, 1978)

• Known Predators

  • fossa, (Crypotporcta ferox)
  • feral dogs, (Canis lupus familiaris)
  • African wildcats, (Felis silvestris )
  • European wildcats, (Felis lybica)
  • humans, (Homo sapiens)

Ecosys­tem Roles

Co­querel’s sifaka are prey for a num­ber of na­tive and in­tro­duced ver­te­brate preda­tors. As seed preda­tors, Co­querel’s sifaka may help dis­perse seeds as well. There is no in­for­ma­tion avail­able re­gard­ing par­a­sites of this species. (Jolly, 1966; Richard, 1978)

• Ecosystem Impact
• disperses seeds

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

Co­querel’s sikafas have been the sub­ject of many stud­ies that may pro­vide in­sight on the evo­lu­tion­ary his­tory of pri­mates, specif­i­cally that of hu­mans. They have also been the sub­ject of var­i­ous re­search ef­forts, in­clud­ing those in­ves­ti­gat­ing the evo­lu­tion of color vi­sion, fe­male dom­i­nated so­ci­ety, evo­lu­tion of pa­ter­nal care, and causes of spe­ci­a­tion. Co­querel's sifakas are com­monly hunted by the peo­ple of Mada­gas­car. In ad­di­tion, be­cause lemurs are en­demic to Mada­gas­car, the emerg­ing eco-tourism in­dus­try ben­e­fits sig­nif­i­cantly from their pres­ence. (Grieser, 1992; Kap­peler, 1991; Kubzdela, et al., 1992; Mayor, et al., 2004; Pas­torini, et al., 2001; Veilleux and Bol­nick, 2009)

• Positive Impacts
• food
• ecotourism
• research and education

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

There are no known ad­verse ef­fects of Co­querel’s sifaka on hu­mans'.

Con­ser­va­tion Sta­tus

Co­querel’s sifakas are clas­si­fied as an en­dan­gered species on the IUCN's Red List of Threat­ened Species. The most im­me­di­ate threat is habi­tat loss due to de­for­esta­tion and slash and burn farm­ing. Trees are ei­ther cleared for farm­ing, rais­ing live­stock or for char­coal pro­duc­tion. In ad­di­tion to re­duc­ing the amount of po­ten­tial habi­tat for Co­querel's sifakas, de­for­esta­tion also re­duces for­age avail­abil­ity. Hunt­ing pres­sure is also a major con­cern. Co­querel's sifakas are cur­rently found in two pro­tected areas: the Ankarafantsika Na­tional Park and the Bora Spe­cial Re­serve. How­ever, il­le­gal hunt­ing is thought to be com­mon in these areas as well. In­creased pre­da­tion by in­tro­duced species has neg­a­tively im­pacted this species as well. PAW (Pro­jects for An­i­mal Wel­fare) of Mada­gas­car was founded in 2011 to com­bat the threat of in­tro­duced cats and dogs. The group is a non-profit that seeks to spay and neuter the pop­u­la­tion of cats and dogs on the is­land so that they will not threaten the na­tive wildlife. Co­querel's sifakas are listed under Ap­pen­dix 1 by CITES (the Con­ven­tion on In­ter­na­tional Trade in En­dan­gered Species of Wild Fauna and Flora). (But­ler, 2008; "Co­querel's Sifaka", 2011; "Pro­p­ithe­cus co­quereli", 2008; Richard, 2003)

• IUCN Red List

  Endangered
  More information

• IUCN Red List

  Endangered
  More information

• US Federal List

  No special status

• CITES

  Appendix I

• State of Michigan List

  No special status

Other Com­ments

Co­querel’s sifakas were con­sid­ered a sub­species of Ver­reaux’s sifaka. The pop­u­lar chil­dren’s show Zo­boomafoo is based on a real Co­querel’s sifaka named Jov­ian who lives at the Duke Lemur Cen­ter. ("Co­querel's Sifaka", 2011; "Pro­p­ithe­cus co­quereli", 2008; Mayor, et al., 2004)

Con­trib­u­tors

Ricki Old­enkamp (au­thor), North­ern Michi­gan Uni­ver­sity, Mary Mar­tin (ed­i­tor), North­ern Michi­gan Uni­ver­sity, John Berini (ed­i­tor), An­i­mal Di­ver­sity Web Staff.

Ref­er­ences

Duke Lemur Cen­ter. 2011. "Co­querel's Sifaka" (On-line). Duke Lemur Cen­ter Study­ing and Car­ing for Lemurs. Ac­cessed Feb­ru­ary 18, 2011 at http://​lemur.​duke.​edu/​category/​diurnal-lemurs/​coquerels-sifaka/​.

In­ter­na­tional Union for Con­ser­va­tion of Na­ture and Nat­ural Re­sources. 2008. "Pro­p­ithe­cus co­quereli" (On-line). Ac­cessed Jan­u­ary 24, 2011 at http://​www.​iucnredlist.​org/​apps/​redlist/​details/​18355/​0/​full/​print.

Bas­t­ian, M., D. Brock­man. 2007. Pa­ter­nal Care in Pro­p­ithe­cus ver­reauxi co­quereli. In­ter­na­tional Jour­nal of Pri­ma­tol­ogy, 28: 305-313.

But­ler, R. 2008. "Wild Mada­gas­car" (On-line). Feral Beasts Threaten Lemurs in Mada­gas­car. Ac­cessed March 18, 2011 at http://​news.​mongabay.​com/​2007/​0205-interview_​sauther.​html.

Camp­bell, J., K. Glenn, B. Grossi, J. Eise­mann. 2001. Use of Local North Car­olina Browse Species to Sup­ple­ment the Diet of a Cap­tive Colony of Fo­liv­o­rous Pri­mates (Pro­p­ithe­cus sp.). Zoo Bi­ol­ogy, 20: 447-461.

Fich­tel, C., C. P. van Schaik. 2006. Se­man­tic Dif­fer­ences in Sifaka (Pro­p­ithe­cus ver­reauxi) Alarm Calls: A Re­flec­tion of Ge­netic or Cul­tural Vari­ants?. Ethol­ogy, 112: 839-849.

Grieser, B. 1992. In­fant De­vel­op­ment and Pa­ter­nal Care in Two Species of Sifakas. Pri­mates, 33: 305-314.

Hayes, A., T. Morelli, P. Wright. 2005. The Chem­istry of Scent Mark­ing in Two Lemurs: Lemur catta and Pro­p­ithe­cus ver­reauxi co­quereli. Pp. 159-167 in R Mason, M LeMas­ter, D Muller-Schawarze, eds. Chem­i­cal Sig­nals in Ver­te­brates 10. New York: Springer Sci­ence Busi­ness+Media, Inc.

Jolly, A. 1966. Lemur Be­hav­ior: A Mada­gas­car Field Study. Chicago: The Uni­ver­sity of Chicago.

Kap­peler, P. 1991. Pat­terns of Sex­ual Di­mor­phism in Body Weight among Prosimian Pri­mates. In­ter­na­tional Jour­nal of Pri­ma­tol­ogy, 57: 132-146.

Kubzdela, K., A. Richard, M. Pereira. 1992. So­cial Re­la­tions in Semi-Free Rang­ing Sifakas (Pro­p­ithe­cus ver­reauxi co­quereli) and the Ques­tion of Fe­male Dom­i­nance. Amer­i­can Jour­nal of Pri­ma­tol­ogy, 28: 139-145.

Mayor, M., J. Som­mer, M. Houck, J. Za­onar­iv­elo, P. Wright, C. In­gram, S. Engel, E. Louis. 2004. Spe­cific Sta­tus of Pro­p­ithe­cus spp.. In­ter­na­tional Jour­nal of Pri­ma­tol­ogy, 25/4: 875-900.

Pas­torini, J., M. Forstner, R. Mar­tin. 2001. Phy­lo­ge­netic His­tory of Sifakas (Pro­p­ithe­cus: Lemu­ri­formes) De­rived from mtDNA Se­quences. Amer­i­can Jour­nal of Pri­ma­tol­ogy, 53: 1-17.

Rako­toarisoa, G., G. Shore, S. Mcguire, S. En­g­berg, E. Louis, R. Bren­ne­man. 2006. Char­ac­ter­i­za­tion of 20 mi­crosatel­lite marker loci in Co­querel's sifaka (Pro­p­ithe­cus co­quereli). Mol­e­c­u­lar Ecol­ogy Notes, 6: 1119-1121.

Richard, A. 1978. Be­hav­ioral Vari­a­tion: Case Study of a Mala­gasy Lemur. Cran­bury, New Jer­sey: As­so­ci­ated Uni­ver­sity Presses, Inc.

Richard, A. 2003. Pro­p­ithe­cus, Sifakas. Pp. 1345-1348 in S Good­man, J Ben­stead, eds. The Nat­ural His­tory of Mada­gas­car. Chicago: The Uni­ver­sity of Chicago Press.

Tat­ter­sall, I. 1982. The Pri­mates of Mada­gas­car. New York: Colom­bia Uni­ver­sity Press.

Tay­lor, L. 2008. Old Lemurs: Pre­lim­i­nary Data on Be­hav­ior and Re­pro­duc­tion from the Duke Uni­ver­sity Pri­mate Cen­ter. Pp. 319-333 in J Flea­gle, C Gilbert, eds. Elwyn Si­mons: A Search for Ori­gins. New York: Springer Sci­ence Busi­ness+Media, LLC.

Veilleux, C., D. Bol­nick. 2009. Opsin Gene Poly­mor­phism Pre­dicts Trichro­macy in a Cath­e­meral Lemur. Amer­i­can Jour­nal of Pri­ma­tol­ogy, 71: 86-90.