Procolobus verusolive colobus

Ge­o­graphic Range

Pro­colobus verus is found on the west­ern coast of Africa, from Sierra Leone to Tongo. There is also an iso­lated pop­u­la­tion in east­ern Nige­ria.

(Bur­ton and Pear­son, 1988; Oates and White­sides, 1990; Flan­nery, 2000; Nowak, 1997) (Bur­ton and Pear­son, 1988; Flan­nery, 2000; Nowak, 1997; Oates and White­sides, 1990)

Habi­tat

Olive colobus mon­keys are ar­bo­real and are re­stricted to rain­for­est habi­tat. They pre­fer the dense un­der­story of the for­est, often near water. Pro­colobus verus some­times trav­els into the mid­dle canopy to sleep, but never ven­tures to the upper stra­tum.

(Bur­ton and Pear­son, 1988; Flan­nery, 2000; Nowak, 1997) (Bur­ton and Pear­son, 1988; Flan­nery, 2000; Nowak, 1997)

Phys­i­cal De­scrip­tion

Pro­colobus verus is the small­est and the most drab col­ored of all African colobus mon­keys, bear­ing olive col­ored hair with a tinge of brown on top and gray­ish un­der­parts. Weights range from 2 to 4.5 kg, and body lengths of 90 to 430 mm are re­ported. Pro­colobus verus has a sim­i­lar body struc­ture to black and white colobus mon­keys, but olive colobus mon­keys have a small crest on top of the head and the most re­duced thumb and largest feet of any colobine. Males are equal in size to fe­males with rel­a­tively larger ca­nines than fe­males.

Pro­colobus verus pos­sesses six cusps on the lower third mo­lars.

(Bur­ton and Pear­son, 1988; Nowak, 1997) (Bur­ton and Pear­son, 1988; Nowak, 1997)

  • Sexual Dimorphism
  • sexes alike
  • Range mass
    2.2 to 4.5 kg
    4.85 to 9.91 lb
  • Range length
    90 to 430 mm
    3.54 to 16.93 in

Re­pro­duc­tion

These colobines are re­ported to be polyg­y­nous.

Olive colobus mon­keys have a ges­ta­tion pe­riod of 5 to 6 months, with no spe­cific breed­ing sea­son. Fe­males re­pro­duce about every two years and usu­ally bear only one young at a time. Fe­males reach sex­ual ma­tu­rity around 3 to 4 years old, males around 5 to 6 years old. Fe­male P. verus have per­ineal or­gans that swell dur­ing es­trus. (Flan­nery, 2000)

  • Breeding interval
    Females can produce young once every 2 years.
  • Breeding season
    Breeding in this species occurs throughout the year.
  • Average number of offspring
    1
  • Range gestation period
    5 to 6 months
  • Range age at sexual or reproductive maturity (female)
    3 to 4 years
  • Range age at sexual or reproductive maturity (male)
    5 to 6 years

Fe­male P. verus carry their young around in their mouths for a few weeks after birth, a be­hav­ior not ob­served in Colobus species. As the young ma­tures, it is car­ried on the ab­domen of the mother. Moth­ers pro­vide milk, groom­ing and pro­tec­tion for the young. The role of males in care of in­fants has not been re­ported.

  • 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
  • extended period of juvenile learning

Lifes­pan/Longevity

The lifes­pan of these an­i­mals has not been re­ported, but other leaf eat­ing mon­keys rarely live in ex­cess of 30 years in cap­tiv­ity. It is likely that P. verus is sim­i­lar. (Nowak, 1997; Nowak, 1997)

  • Average lifespan
    Status: wild
    20 years
  • Average lifespan
    Status: captivity
    29 years

Be­hav­ior

Pro­colobus verus is di­ur­nal and uses quadrapedal lo­co­mo­tion. Troops of P. verus con­sist of an old male, sev­eral fe­males and their off­spring. Group size ranges from 10 to 15 in­di­vid­u­als. This species is often seen group­ing with other mon­keys, es­pe­cially Diana mon­keys. When an alarm call is sounded, usu­ally by a Diana mon­key, P. verus sits very still, cam­ou­flaged by the green color of its pelage.

(Bur­ton and Pear­son, 1988; Oates and White­sides, 1990; Flan­nery, 2000; Noe and Bshary) (Bur­ton and Pear­son, 1988; Flan­nery, 2000; Oates and White­sides, 1990)

Com­mu­ni­ca­tion and Per­cep­tion

Com­mu­ni­ca­tion in these mon­keys is not well de­scribed. How­ever, we may as­sume that they are like other pri­mates, and use var­i­ous means of com­mu­ni­ca­tion. In­cluded in these are vi­sual sig­nals, such as fa­cial ex­pres­sions and body pos­tures, vo­cal­iza­tions, and tac­tile com­mu­ni­ca­tion, in­clud­ing groom­ing, play­ing, and ag­gres­sion. (Nowak, 1997)

Food Habits

Pro­colobus verus for­age in un­der­story and mid­dle canopy of the for­est, feed­ing mainly on young leaves. These mon­keys are highly se­lec­tive feeder, but sea­son­ally they will also eat seeds, flow­ers, and peti­oles. When young fo­liage is avail­able, they ig­nore ma­ture leaves. Pro­colobus verus has a sac­cu­lated stom­ach to as­sist in the break­down of cel­lu­lose in its pri­mar­ily fo­liv­o­rous diet.

(Flan­nery, 2000; Oates, 1988) (Flan­nery, 2000; Oates, 1988)

  • Plant Foods
  • leaves
  • seeds, grains, and nuts
  • flowers

Pre­da­tion

Pro­colobus verus is the most ac­com­plished leaper in the Tai For­est, where it com­monly lives. This ca­pa­bil­ity of P. verus al­lows it to avoid preda­tors that share this habi­tat. It also fre­quently groups with Diana mon­keys to avoid pre­da­tion. Pro­colobus verus is hunted by hu­mans for its meat and skin.

(Noe and Bshary)

Ecosys­tem Roles

The ecosys­tem role of these an­i­mals is not well un­der­stood. We may as­sume that to the ex­tent that other an­i­mals prey upon these mon­keys, they serve as a con­trol on preda­tor pop­u­la­tions. They may also help to dis­perse seeds.

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

Pro­coloby verus is hunted by hu­mans for food.

  • Positive Impacts
  • food

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

There are no known ad­verse ef­fects of P. verus on hu­mans. How­ever, as pri­mates, they may carry some of the same dis­ease or­gan­isms which af­fect peo­ple.

Con­ser­va­tion Sta­tus

Al­though this species is not of spe­cial con­ser­va­tion con­cern, all pri­mates are listed as CITES ap­pen­dix II be­cause they are vul­ner­a­ble to habi­tat loss.

Con­trib­u­tors

Nancy Shef­ferly (ed­i­tor), An­i­mal Di­ver­sity Web.

Leah Thomp­son (au­thor), Uni­ver­sity of Michi­gan-Ann Arbor, Kate Teeter (ed­i­tor), Uni­ver­sity of Michi­gan-Ann Arbor.

Glossary

Ethiopian

living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.

World Map

acoustic

uses sound to communicate

altricial

young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

arboreal

Referring to an animal that lives in trees; tree-climbing.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

diurnal
  1. active during the day, 2. lasting for one day.
endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

fertilization

union of egg and spermatozoan

folivore

an animal that mainly eats leaves.

food

A substance that provides both nutrients and energy to a living thing.

herbivore

An animal that eats mainly plants or parts of plants.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

polygynous

having more than one female as a mate at one time

rainforest

rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

social

associates with others of its species; forms social groups.

tactile

uses touch to communicate

terrestrial

Living on the ground.

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

year-round breeding

breeding takes place throughout the year

Ref­er­ences

Bur­ton, J., B. Pear­son. 1988. The Collins Guide to the Rare Mam­mals fo the World. Lex­ing­ton, Mass­a­chu­setts: The Stephen Greene Press.

Flan­nery, S. 2000. Ac­cessed Sep­tem­ber 23, 2001 at www.​primate.​wisc.​edu/​pin/​factsheets/​procolobus_​verus.​html.

Noe, R., R. Bshary. "As­so­ci­a­tion of red and olive colobus mon­keys with diana mon­keys" (On-line). Ac­cessed 11/14/2001 at www.​mpi-seewiesen.​mpg.​de/​~knauer/noe/taenc.​html.

Nowak, R. 1997. "Walker's Mam­mals of the World/Olive Colobus Mon­key" (On-line). Ac­cessed No­vem­ber 12, 2001 at www.​press.​jhu.​edu/​walkers_​mammals_​of_​the_​world/​primates/​primates.​cercopithecidae.​procolobus.​html.

Oates, J. 1988. The diet of the olive colobus mon­key, *Pro­colobus verus*, in Sierra Leone. In­ter­na­tional Jour­nal of Pri­ma­tol­ogy, 9/5: 457-478.

Oates, J., G. White­sides. 1990. As­so­ci­a­tion be­tween Olive Colobus, *Pro­colobus verus*, Diana guenons, *Cer­co­p­ithe­cus diana*, and other For­est Mon­keys in Sierra Leone.. Amer­i­can Jour­nal of Pri­ma­tol­ogy, 21/2: 129-146.