Vervet Monkey (Chlorocebus pygerythrus) Fact Sheet: Reproduction & Development

Lack elaborate courtship displays (Isbell and Enstam-Jaffe 2013)

• Female controls successful mating, though males typically initiate interest (Andelman 1987; Isbell and Enstam-Jaffe 2013)
  • Male nuzzles female's genitalia, grabs her hips, or embraces her from behind (Estes 1990)
  • Female sits down, moves away, or aggressively hits and bites the male to reject his advances (Andelman 1987)
  • Receptive female directs hindquarters toward interested male ("presenting") (Struhsaker 1967d)
• Female receptive to sexual activity for long periods(Estes 1990)
  • Copulate even when pregnant (Estes 1990)
  • At Segera, copulations observed nearly year-round (Isbell and Enstam-Jaffe 2013)

Mating brief, <30 seconds; single mount ejaculation (Andelman 1987; Isbell and Enstam-Jaffe 2013)

• Interference with copulation minimal (Struhsaker 1967b)
• Small numbers of males monopolize copulation with group females(Struhsaker 1967b)
  • Higher ranked males receive more overall mating attempts than lower ranked counterparts (Andelman 1987)
  • Rank plays a smaller role during times for optimal conception (Andelman 1987)

Breed seasonally (Estes 1990; Isbel and Enstam-Jaffe 2013)

• Timing varies by locality
• Associated with patterns in rainfall and food availability

No paternal care of offspring (Andelman 1987)

Gestation

• In managed care
  • c. 163-165 days (Andelman 1987; Isbell and Enstam-Jaffe 2013; Rowell 1970)
• In the wild
  • 156-161 days, estimate for a single female (Isbell and Enstam-Jaffe 2013)

Birth

• Seasonal in most locations
  • In Amboseli National Park, >85% of births occur Oct-Dec (Andelman 1987; Isbell and Enstam-Jaffe 2013)
  • In Samburu National Reserve, >85% of births occur Nov-Dec (Isbell and Enstam-Jaffe 2013)
  • In Zambia, along the Zambezi River near Victoria falls, most births occur Oct-Jan (Lancaster 1971)
• Produce 1 infant every 1-2 years (Isbell and Enstam-Jaffe 2013)
  • Birth weight: 300-400 g (0.7-0.9 lb) (Isbell and Enstam-Jaffe 2013)
  • Eyes open at birth (Kirkwood and Stathatos 1992)
  • Cling to mother and suckle shortly after birth (Kirkwood and Stathatos 1992)

Interbirth interval

• 13-14 months (Cheney and Seyfarth 1987; Cheney et al. 1988; Isbell et al. 2009)

Infant (0-0.5 yr)

• Appearance
  • Black coat at birth; changes to resemble an adult by 3 months of age (Isbell and Enstam-Jaffe 2013; Lancaster 1971)
  • Face and ears pink (Isbell and Enstam-Jaffe 2013)
• Maternal Care
  • Birth to 3 months
    • Carried ventrally by mother; rarely ride on mother's back (Lancaster 1971; Struhsaker 1967d)
    • Older siblings or other juvenile females may provide temporary care; typically after the first few weeks of life (Lancaster 1971)
    • Little care provided by mothers once infants reach 6-7 weeks of age (Lancaster 1971)
      • Groomed minimally, only when obviously dirty; juvenile females provide most grooming (Lancaster 1971)
  • 3 to 6 months
    • Weaned c. 3 months; complete by c. 18 months (Isbell and Enstam-Jaffe 2013)
    • Carried rarely, only in emergencies (Lancaster 1971)
    • Join in juvenile play (Lancaster 1971)
• Infant mortality
  • Annual mortality: c.41% of infants do not survive their first year (Isbell et al. 2009)
    • As high as 100% in some years (Isbell et al. 2009)
  • Causes of death
    • Predation is the most frequent (known) cause of death (Isbell et al. 2009)
    • Climatic conditions (heavy rainfall) may impact survival (Isbell et al. 2009)
  • Infants orphaned after 12 months of age can survive (Isbell et al. 2009)

Juvenile & Subadult (0.5-4 yr)

• Males
  • Emigrate from natal group just prior to reaching sexual maturity (Cheney and Seyfarth 1983)
    • Transfer is relatively fast; no individual remained solitary > 2 months, one study (Cheney and Seyfarth 1983)
    • Group peers commonly leave together (Cheney and Seyfarth 1983)
• Females
  • Often provide motherly care to young infants
    • Non-reproductive juveniles groom and babysit the offspring of others (Lancaster 1971)

Adult (>4 yr)

• Males
  • Reach sexual maturity at 5-6 yrs of age (Cheney and Seyfarth 1983; Cheney and Seyfarth 1987)
  • May transfer between groups multiple times, possibly for lack of access to reproductive females (Cheney and Seyfarth 1983)
• Females
  • First reproduce: 4-6 yrs of age (Cheney and Seyfarth 1987; Isbell et al. 2009)
    • Mean age 5 yrs, one study (Isbell et al. 2009)
    • Earliest age 3.5 yrs (Isbell and Enstam-Jaffe 2013)
  • Typically do not reproduce every year; unlike patas monkeys (Isbell et al. 2009; Pasternak et al. 2013)
    • Give birth about once every 2 yrs (21 months) (Pasternak et al. 2013)

Managed care

• No AZA estimates

Annual mortality rate

• c. 12-15%, typically (Isbell et al. 2009)
• Extreme predation may raise rates to 45% in some years (Isbell et al. 2009)
• Predation is the largest cause of death in most years (Isbell 1990; Isbell et al. 2009)
  • Responsible for 70% of mortalities in Amboseli (Cheney and Seyfarth 1987)

Predation

• Mammalian predators (Butynski and Kingdon 2013; Ducheminsky et al. Enstam and Isbell 2002; Isbell 1990; Struhsaker 1967a)
  • Domestic dog (Canis familiaris); leopard (Panthera pardus); lion (Panthera leo); African wildcat (Felis lybica); serval (F. serval); cheetah (Acinonyx jubatus); caracal (Caracal caracal); striped and spotted hyena (Hyaena hyaena and Crocuta crocuta); jackals (Canis spp.); hamadryas, olive, and yellow baboon (Papio hamadryas, P. anubis, P. cynocephalus)
• Avian predators (Butynski and Kingdon 2013; Isbell 1990; Struhsaker 1967a)
  • African Crowned Eagle (Stephanoaetus coronatus); Verreaux's Eagle (Aquila verreauxii); Martial Eagle (Polemaetus bellicosus)
• Reptilian predators (Baldellou and Henzi 1992; Butynski and Kingdon 2013; Isbell 1990; Struhsaker 1967a)
  • Central African rock python (Python sebae); Nile crocodile (Crocodylus niloticus)

Parasites and disease

• Effects of various parasitic, viral, and bacterial infections unknown (from Isbell and Enstam-Jaffe 2013 unless otherwise noted)
  • Parasitic infections
    • Protozoans: Babesia macaci, B. pitheci, and Balantidium coli (Enstam-Jaffe 2013; Wren 2006)
    • Helminthes: Schistosoma mattheei; S. mansoni; Cercopithifilaria verveti; Dirofilaria aethiops; Enterobius bipapillatus; Trichuris trichiura (Enstam-Jaffe 2013; Wren 2006)
  • Viral infections
    • Simian immunodeficiency virus (SIV) (Butynski and Kingdon 2013; Isbell and Enstam-Jaffe 2013)
      • Endemic; appear to harbor the virus but are unaffected carriers
      • High rate of infection in adults (Jolly et al. 1996)
        • Little evidence for maternal transmission to offspring (Jolly et al. 1996)
    • Flavivirus/Yellow fever virus
    • HTLV-like STLV-1
    • Papillomavirus SA-12
    • Spumavirus simian foamy virus
    • Lentivirus SIV agm
    • Alphavirus-SFV complex Chikungunya and Polyomavirus SAV-12
  • Bacterial infections
    • Salmonella sp.; Shigella sp.; Borrelia harveyi; Chlamydia sp.; Leptospira sp.; Rickettsia cornorii

Image credit: © David Schenfeld via Flickr. Some rights reserved.

Andelman (1987)
Baldellou and Henzi (1992)
Butynski and Kingdon (2013)
Cheney and Seyfarth (1983)
Cheney and Seyfarth (1987)
Cheney et al. (1988)
Enstam and Isbell (2002)
Estes (1990)
Isbell (1990)
Isbell and Enstam-Jaffe (2013)
Isbell et al. (2009)
Jolly et al. (1996)
Kirkwood and Stathatos (1992)
Lancaster (1971)
Pasternak et al. (2013)
Rowell (1970)
Struhsaker (1967a,b,d)
Wren (2006)