Wombats (Vombatus and Lasiorhinus spp.) Fact Sheet: Reproduction & Development

• Births timed to coincide with beginning of peak food supply
• Common wombat (Jackson 2003)
  • Breed once/year
  • Timing typically correlated with latitude and elevation
    • September-January in southeastern Australia
    • December-March in New South Wales
    • March-July in northern Victoria
  • Can breed any time of year in areas with good food supply
    • Polyestrous (more than one estrus per year)
    • Observations in managed care: estrus cycle of 32-34 d, estrus lasting 24-81 h (Böer 1998)
• Northern hairy-nosed wombat (DEHC 2012; Horsup 2004)
  • Females seasonally polyestrous
    • 50-80% breed in years with high rainfall, good food supply
  • Most births occur November to April
• Southern hairy-nosed wombat (Jackson 2003)
  • Breed about twice every 3 y
    • Generally not in low-rainfall years
  • Defined breeding season
    • Most births occur late July to September
    • If pouch young is lost early in lactation, females may breed again in same season (Taggart & Temple-Smith 2008)

• Characteristics observed in 2 species - ritualized, vigorous, demanding
• Common wombat
  • Polygamous (McIlroy 2008)
  • Courtship/mating observed in wild (Marks 1998) and managed care (Böer 1998)
    • Repeated behavioral sequence of sniffing, attraction, chasing, biting, grasping, and copulation
    • Essentially same as southern hairy-nosed wombat (see below)
• Southern hairy-nosed wombat
  • Monogamous (Taggart & Temple-Smith 2008)
  • Courtship observed in 12 captive wombats (Hogan et al. 2010)
    • Courtship behaviors
      • Urine smelling - male smells female's urine, may use flehmen (sniffing with retracted upper lip, bared gum, wrinkled nose)
      • Approach - male repeatedly approaches female from behind
      • Urogenital sniff - male sniffs female's urogenital area
      • Evading - female turns rump away, retreats; may bite/chase male away
      • Nudging - female approaches male, makes nose-to-nose contact; may wake up sleeping male
      • Attraction actions - female stops in front of male, presents rump and often digs/urinates
      • Chase - female initiates by fast, hopping walk
    • Mating behaviors
      • Rump bite - chase speeds up to run, male delivers hard bite to female's rump; female usually stops
      • Grasp and restraint - male jumps on females back, grasps hips, flips her on side
      • Kicking and turning - female kicks at male, tries to move rump away and right herself
      • Catch and release - if male loses grip, repeats previous 3 behaviors
      • Coitus - male inserts penis and thrusts while pinning female with teeth in rump and forelimbs around pelvis
      • Break - male releases female; after recovery, male or female may reinstigate courtship/mating

• Short - about 20-21 days (Jackson 2003)

• Birth (Böer 1998; Jackson 2003)
• Litter size: usually 1
• Young emerges at early embryonic stage
  • About 0.4 g (0.014 oz) at birth (Taggart et al. 2008)
  • Worm-like, naked, front limbs developed with nails, hind limbs still tissue buds
• Young crawls from birth canal into pouch, attaches to 1 of the 2 teats (uses same teat throughout development)
• Infant/Pouch Life (Böer 1998; Horsup 2004; Jackson 2003)
• Time young ("joey") spends in pouch varies between species
  • Common and southern hairy-nosed wombats: 7-9 mo
  • Northern hairy-nosed wombat: 8-9 mo
• Permanent emergence from pouch preceded by temporary excursions
  • Mother follows young or listens to its movements
  • Young begins adding solids to its diet, imitating mother's food choices
    
• Subadult
• Common wombat
  • Weaning at 12-15 mo, takes about 50 d (McIlroy 2008)
  • During weaning, parents aggressive toward young (Böer 1998)
• Southern hairy-nosed wombat
• Weaning around 12 mo (Taggart & Temple-Smith 2008)
• Adult
  • Common wombat
    • Adult size at 2 y, sexual maturity at >2 y old (McIlroy 2008)
    • Body continues growing slowly after sexual maturity (Triggs 1996)
  • Southern hairy-nosed wombat
    • Sexual maturity at about 3 y old (Taggart & Temple-Smith 2008)

(Horsup 2004; Jackson 2003)

Wild Populations

• Wombats, general
  • Little known
  • Triggs (1996), Jackson (2003): roughly 15 years

Managed Care

• Wombats, general
  • No AZA estimates
  • About 20 years, according to Triggs (1996)
• Common wombat
  • 12–15 years
• Southern hairy-nosed wombat
  • 10–15 years
• Northern hairy-nosed wombat
  • Unknown

(McIlroy 2008; Marks 1998; Ramp et al. 2005; Stott 1998)

• Starvation
  • Usually during prolonged droughts
• Sarcoptic mange
  • Sporadic outbreaks cause significant morbidity and mortality - outbreaks could result in decline, possible extinction of small, isolated populations
• Predation
  • See Interspecies Interactions
• Collisions with road vehicles (Roger et al. 2011)
• Pest control by humans (Marks 1998; Stott 1998)
  • Farmers and graziers consider common wombats a major problem, want to limit spread of southern hairy-nosed wombats
  • Concerns:
    • Crop destruction
    • Fence damage - burrow under dingo fences, allowing predators access to sheep
    • Warrens undermine dams, roads, etc. and promote topsoil loss
    • Road hazard at night - vehicle damage, risk to human life
  • Control measures
    • Historically (no longer permitted by law) - fumigation with Phostoxin and Larvicide
    • Trapping and shooting
    • Destruction of warrens by explosives

A wombat joey peeks out of its mother's pouch.

Joeys spend up to 9 months in the pouch.

Image credit: © San Diego Zoo Wildlife Alliance. All rights reserved.

Böer (1998)
DEHC (2012)
Hogan et al. (2010)
Horsup (2004)
Jackson (2003)
Marks (1998)
McIlroy (2008)
Moeller (1990)
Roger et al. (2011)
Stott (1998)
Taggart et al. (2007)
Taggart & Temple-Smith (2008)
Triggs (1996)
Wells (1989)