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Gelada (Theropithecus gelada) Fact Sheet: Reproduction & Development

Courtship and Mating

Soliciting partners (from Kawai 1979)

  • Both sexes initiate sexual interactions
    • Females present to solicit a male
      • Circle male; walking around him and emitting solicit-calls
      • Gaze at his face
      • Stand with tail raised; genital area directed toward male's face
    • Males slowly approach to solicit a female
      • May kiss and touch the red patch on the female's breast while lip-smacking

Copulation (from Kawai 1979)

  • Mating brief; lasting c. 10 seconds
    • Male mounts female from behind
    • Both partners typically vocalize throughout

Reproduction

Year-round reproduction

  • Copulation observed throughout the year (Kawai 1979)

Female reproductive cycle (from Dunbar and Dunbar 1974a)

  • Physical features indicate estrus state
    • Changes in color of skin on chest and paracallosal region (located on either side of the vulva immediately below the calloused patches)
    • Growth of beaded vesicles surrounding chest skin
  • Estrus cycle
    • Chest bright pink throughout
      • Beading develops, which turns white in anoestrous
    • Paracallosal skin (PCS) bright pink throughout
    • Vulva gradually opens and protrudes before retreat and closure in anoestrous
  • Pregnancy
    • Chest bright pink throughout
    • PCS turns from bright pink to scarlet red in later stages of gestation
    • Vulva closed throughout
  • Lactation
    • Chest scarlet with young infant (one with a black natal coat); turns pale to bright pink as infant ages
    • PCS turns from bright pink to pale pink
    • Vulva closed

Gestation and Birth

Gestation

  • Duration
    • c. 5.5-6 months (Dunbar 1980; Hayssen et al. 1993)

Birth (from Dunbar and Dunbar 1974b unless otherwise noted)

  • Timing and behavior
    • Deliver at night or early morning, most often
      • Reports of birth in late afternoon (Lee et al. 2010)
      • Stands in a half crouch position
  • Brood characteristics
    • 1 infant typically
      • Black natal coat, skin light (Bergman and Beehner 2013; Dunbar 1980; Kawai 1979)
      • Eyes closed, though opening within c. 1-2 hours
    • Birth weight
      • None reported

Interbirth interval (time between consecutive births)

  • c. 2-3 years (Dunbar 1980)

Life Stages

Infants (< 5 months) (from Kawai 1979 unless otherwise noted)

  • Carried by mother
    • Cling to mother's belly during travel for a few days after birth
    • Ride on her back or that of other group members; often with tails entwined
  • Form play groups
    • Similar-age infant groups
    • Rarely stray far from natal (birth) group
  • Weaned c. 12-18 months (Hayssen et al. 1993)

Juveniles (0.5-3.5 years) (from Dunbar 1980 unless otherwise noted)

  • Appearance
    • Pelage resembles adult by c. 5 months
    • Muzzle rounded by 1.5-2.5 years
      • Appears as adult by 1.5-2.5 years
  • Males
    • Leave natal group to join an all-male group (Bergman and Beehner 2013)
    • Remain in all-male group for 2-4 years (Bergman and Beehner 2013)
  • Females
    • Remain in natal group for life (Bergman and Beehner 2013)

Subadults (3.5-6 years) (from Dunbar 1980 unless otherwise noted)

  • Males
    • Puberty c. 3-4 years (Hayssen et al. 1993)
    • Attempt to acquire access to reproductive females (Bergman and Beehner 2013)
      • Act to unseat the existing leader of a one-male unit (Bergman and Beehner 2013)
      • Seek associations with peripheral and/or juvenile females (Bergman and Beehner 2013)
  • Females
    • First estrus: 3-4 years (Kawai et al. 1983)
    • First reproduce: 4-4.5 years
      • Reproductive before achieving full adult size

Adults (>6 years) (from Dunbar 1980 unless otherwise noted)

  • Males
    • Sexually mature c. 8-9 years (Hayssen et al. 1993)
    • Cape and whiskers fully develop and physical growth complete by 8.5-9 years (Dunbar 1980; Kawai et al. 1983)
    • Maximum weight by 12 years
      • Color of cape and chest gradually declines
    • Do not interact with females outside own OMU (Dunbar and Dunbar 1975)
  • Females
    • Core of gelada society (Bergman and Beehner 2013)
      • Maintain strong bonds irrespective of OMU leader (Bergman and Beehner 2013)
    • Physical growth complete by 8.5 years
    • Reproductive activity tapers with age

Longevity

In managed care

  • Typical lifespan
    • c. 20 years (Putman 2007)
  • Maximum lifespan
    • > 35 yrs (Putman 2007; Weigl 2005)

In the wild

  • 14-15 years (Dunbar 1980)

Mortality

Major causes of adult mortality

  • Parasitic infection (from Dunbar 1980; Kawai 1979)
    • Coenurus (a tapeworm of the genus Multiceps) larvae cause small to large swellings in muscle tissue
      • Extremely large swellings impair movement
      • Growths may eventually weep pus, causing severe pain and compromised immune systems
  • Old age
    • Aged individuals (those in the oldest age classes) demonstrate the highest mortality rates, one study (Dunbar 1980)
  • Inclement weather
    • Heavy rain and subzero temperatures may contribute to respiratory and other infectious diseases (Bergman and Beehner 2013; Dunbar 1980)

Infant mortality low (from Dunbar 1980)

  • Strongly influenced by rainfall
    • Higher mortality during the wet season

Predators

  • Negligible source of mortality (Dunbar 1980)
    • Few large carnivores live in the region (Dunbar 1980; Kawai 1979)

Birth and Infant Development


Geleda mother and baby

Females typically give birth to a single infant at night or in early morning. Infants have black hair and light colored skin. The hair turns brown by c. 5 months of age.

Image credit: © Boquet from Flickr. Some rights reserved.

Page Citations

Bergman and Beehner (2013)
Dunbar (1980)
Dunbar and Dunbar (1974a,b)
Dunbar and Dunbar (1975)
Hayssen et al. (1993)
Kawai (1979)
Kawai et al. (1983)
Lee et al. (2010)
Putman (2007)
Weigl (2005)

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