Sugar Glider (Petaurus breviceps) Fact Sheet: Reproduction & Development

Mating system

• Flexible, depending on food availability (Jackson 2015b)
• Often polygynous (males mate with multiple females) (Quin 1995; Jackson 2015a)
  • Offspring sired by one or two dominant adult males in each group (Nowak 2018a)
• Monogamy may occur in locations where food is very limited (Quin 1995)

Breeding

• Sexual maturity
  • Approximately 12 to 18 months of age (Jackson 2000c)
• Breeding season
  • Northern Australia and New Guinea
    • Breed throughout the year (Howard 1989; Jackson 2000c; Nowak 2018a)
    • Peak in late dry to early wet season (Jackson 2015a)
  • Southeastern Australia
    • Single breeding season that begins in winter or early spring (Suckling 1984; Jackson 2015a; Jackson 2015b)
      • June to November (Smith 1973; Flannery 1995)
  • Young weaned when insects are abundant (spring) (Lindenmayer 2002; Jackson 2015b)
    • Insects allow mother to produce protein-rich milk for young
• Females have a pouch with teats to suckle young (Smith 1973; Suckling 1984)
  • During nonbreeding season, pouch is shallow and thin walled
  • About three months before birth of young, pouch deepens and becomes more stiff
  • Shrinkage after birth of young or if no young produced
• All females in a group breed (Jackson 2015a)

Gestation

• Gestation period
  • 15 to 17 days [data from managed care; n = 3] (Smith 1971; Jackson 2015b)
• Litter size
  • Typically 2 young (Jackson 2000c; Salas et al. 2016)
    • Less commonly, 1 young (e.g., Suckling 1984)
    • Rarely 3 young (Smith 1971; Collins 1973)

Birth

• Weight at birth
  • 0.19 g (0.0067 oz) [data from managed care; n = 2] (Smith 1971; Jackson 2015b)
• Born with well-developed forelimbs and sense of smell (Holloway and Geiser 2000; Jackson 2015b)
  • Climb to mother’s pouch
  • Attach to one of four teats
• Also see “Newborn” in Life Stages

Interbirth interval

• Females produce 1 to 2 litters per year (Quin 1995; Jackson 2000c)
  • Produce a second litter if the first dies or is weaned before the end of the breeding season (Smith 1971; Quin 1995; Jackson 2015b)

General

• Little known about the parental care of lesser gliders in the wild (Jackson 2015b)

Investment in care

• Paternal involvement requires further study (Jackson 2015a)
  • Females and males care for young (Goldingay 2010; Jackson 2015a)
    • Sadler and Ward (1999) report an adult male grooming young in a nest
• Family members keep young warm while mother forages (Holloway and Geiser 2000; Goldingay 2010; Nowak 2018a)
• Mother must provide more milk after young are able to thermoregulate, leave the pouch, and are more active (Jackson 2015b)
  • Young use about 6 times more energy after gaining ability to thermoregulate
• Maternal care ends after weaning (Henry and Suckling 1984)
  • About 4 months after birth (Lindenmayer 2002)

Defense of young

• All adult group members defend young (Smith 1971)

Newborn

• Birth
  • No fur (like other marsupials) (Holloway and Geiser 2000)
    • Regulation of body temperature begins at about 100 days old (Holloway and Geiser 2000; Jackson 2015a)
  • Pinkish in color (Smith 1973)
    • No skin pigments
• 12 to 14 days
  • External indicators of sex present (Smith 1971)
• 30 days
  • Fine fur begins to grow (Smith 1971)
• 40 days
  • Release of mother’s nipple (Smith 1971)
• 60 days
  • Young become too large for pouch (Smith 1973)
• 70 days
  • Young leave pouch (Collins 1973; Smith 1973)
    • Remain in group nest, while mother forages, for an additional 40 to 50 days (Suckling 2008)
  • Full development of fur (Smith 1971)
  • New behavior: “curl into a ball,” as observed in adults (Holloway and Geiser 2000)
    • Reduces heat loss on less furred underside
• About 80 days
  • Eyes open (Collins 1973)
• About 90 days
  • Young show defensive behaviors towards non-group members (Schultze-Westrum 1969)
• Also see “Birth” in Gestation and Birth

Juvenile

• By 110 days
  • Transition to juvenile stage of development (Holloway and Geiser 2000)
    • Body covered in fur
    • Improved coordination
• 110 to 120 days
  • Young leave nest and forage alongside mother (Collins 1973; Smith 1973)
  • Soon independent (Fleay 1947)

Adult

• About 250 days (8 months)
  • Reach adult body size (Holloway and Geiser 2000)
• 7 to 10 months
  • Young displaced from family group (Jackson 2015a; Jackson 2015b)
    • See “Dispersal” in Movements and Dispersal

Wild populations

• 4 to 5 years (Suckling 1984; Flannery 1995; Suckling 2008)

Managed care

• Long-lived (Weigl 2005; Nowak 2018a)
• No AZA estimates

Survival rates

• Highest mortality in first 12 to 15 months of life, when dispersing from natal group (Suckling 1984; Quin 1995; Jackson 2015b)
  • Preyed on by birds, large lizards, and feral cats (Suckling 1984)
• Starvation possible when food is scarce (Körtner and Geiser 2000)
• Breeding success varies from year to year (Suckling 1984; Lindenmayer 2002)

Predators

• Birds of prey
  • Owls (Ninox and Tyto spp.) (e.g., Fleay 1947; Henry and Suckling 1984; Suckling 1984; Jackson 2000c; Kavanagh 2002; Bilney et al. 2010; Bilney 2013)
  • Kookaburras (Suckling 1984; Suckling 2008)
• Reptiles
  • Pythons (Jackson 2000c; Suckling 2008)
  • Goannas (monitor lizards; Varanus spp.) (Suckling 1984; Suckling 2008)
• Mammals
  • Feral cats (Suckling 1984; Jackson 2000c; Suckling 2008; Johnson 2011)
  • Possibly fox (Henry and Suckling 1984; Suckling 2008)

Accidental death

• Entanglement in barbed wire (used to fence land) (Lindenmayer 2002; Council 2010)

Diseases

• See Jackson (2003), Johnson and Hemsley (2008), and Johnson (2011)

Parasites (non-comprehensive list)

• Mites (Smith 1973)
• Ticks (Smith 1973)
• Fleas (Lindenmayer 2002)
• Sporozoans (Smith 1973)
• Trematodes (Smith 1973)
• Nematodes (Lindenmayer 2002)
• Toxoplasmosis [wild and outdoor managed care settings] (Johnson 2011)

As newborns, sugar gliders depend on heat generated by their nest mates to stay warm. The fine, silky fur of a youngster grows in by 70 days of age.

Sugar gliders of all ages curl into a ball position to reduce heat loss through their sparsely furred underside.

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