Eastern Blue-tongued Skink (Tiliqua scincoides) Fact Sheet: Reproduction & Development

General

• Live-bearing (Cogger 2014; Wilson and Swan 2017)
  • See Hitz (2004) for overview of female reproductive system
• Age at sexual maturity
  • 561-590 d (Shea 1981)
• Size at sexual maturity varies by population (Shaw 1992)
  • Measurements in SVL (snout-vent length)
  • T. s. intermedia
    • Eastern populations
      • Males: 296-361 mm (10.4-12.7 in)
      • Females: 291-362 mm (10.3-12.8 in)
    • Western populations
      • Males: 269-341 mm (9.5-12.0 in)
      • Females: 264-325 mm (9.3-11.5 in)
  • T. s. scincoides
    • New South Wales
      • Males: 254-334 mm (10.0-13.1 in)
      • Females: 274-351 mm (10.8-13.8 in)
    • Victoria and South Australia
      • Males: 220-315 mm (8.7-12.4 in)
      • Females: 236-302 mm (9.3-11.9 in)
    • Queensland
      • Males: 258-371 mm (10.2-14.6 in)
      • Females 277-359 mm (10.9-14.1 in)

Breeding

• Annual reproductive cycle (Shaw 1992)
• Breeding occurs during the dry season (Shaw 1992; Cronin 2014; Price-Rees, Brown, et al. 2014)
  • Mating: August-October (late winter to spring)
  • Females give birth December-February (early to late summer)
  • Northern populations may breed slightly earlier than southern populations

Pregnancy

• Litter size
  • Most litters 10-11 young (Swanson 1976; Shaw 1992)
    • Minimum: 1 young (Shea 1981)
    • Maximum: 25 young (Shea 1981; Cogger 2014)
  • Increases with female age and body size (Shea 1981)
• Gestation
  • Not well characterized
  • About 3-4 months (Shea 1981; Shaw 1992)
• Birth
  • Females usually give birth during the day, after body has warmed (Hitz 2004)
  • Young born over a period of 1.5-8 hours (Shaw 1992)
  • Size at birth
    • About 90-130 mm (3.5-5.1 in) (snout-vent length) at birth (Swanson 1976; Shaw 1992; Cronin 2014)
  • Weight at birth
    • 8.4-20.7 g (0.30-0.73 oz) (Shaw 1992)
  • Born mid to late summer (December-February) (Shea 1981; Shaw 1992)

Newborns

• Home range thought to be small (Koenig et al. 2001)
• Grow rapidly when have access to abundant food, especially in managed care settings (Koenig et al. 2001)

Juveniles

• Bright adult colors and glossy appearance develop at 8-9 months of age (Horner 2004)
• Juveniles thermoregulate more frequently and use higher environmental temperatures, compared to adults (Phillips 1986b)
  • May aid growth
  • Likely able to better thermoregulate at larger body size
• In managed care, grow rapidly (Shea 1981; Horner 2004)
  • May reach near-adult size in about a year

Wild populations

• Not reported, though thought to be long-lived

Managed care

• About 20 years (Slavens and Slavens 2000; Koenig et al. 2001)

Survival rates

• Not reported

Predators

• Large snakes (e.g., black-headed python Aspidites melanocephalus, mulga snake Pseudechis australis) (Horner 2004)
• Goannas (Samantha Price-Rees, personal communication, 2018)
• Large birds (e.g., kookaburra, falcons) (Horner 2004; Abramjan et al. 2015)
• Dingoes (Horner 2004)
• Domestic dogs and cats (Koenig et al. 2002)
• Juveniles and subadults preyed on by many reptiles, mammals, and birds (Horner 2004)
• Predators of other Australian skinks (Pianka 1969)
  • Monitor lizards (Varanus)
    • Might also prey on T. scincoides (Abramjan et al. 2015)

Accidental death

• See Threats to Survival (in Population & Conservation Status)

Parasites (non-comprehensive list)

(Mike Swan, personal communication, 2018)

• Ticks
• Mites
• Nematode worms

Blue-tongued skinks (Tiliqua spp.) give live birth.

Female Tiliqua scincoides breed annually and typically have 10-11 young per litter.

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