Eastern Blue-tongued Skink (Tiliqua scincoides) Fact Sheet: Behavior & Ecology

Mainly diurnal—but can vary

(Cogger 2014)

• Geographic and seasonal variation
  • In the tropics and hotter climates, most active during early morning and late afternoon (Swanson 1976; Cronin 2014; Samantha Price-Rees, personal communication, 2018)
    • Avoid activity and exposure during hottest time of day (Horner 2004)
  • In temperate areas and cooler months, most active once per day (Samantha Price-Rees, personal communication, 2018)
    • Maximized foraging and seeking mates (Samantha Price-Rees, personal communication, 2018)
  • In northern Australia, largely inactive during the dry season
  • May be inactive during drought and extreme heat in other regions (Samantha Price-Rees, personal communication, 2018)
• Common behaviors
  • Forage (Koenig et al. 2001)
  • Seek mates (Koenig et al. 2001)
  • Warm themselves (Koenig et al. 2001)
    • Reach midday body temperatures of 30-35°C (86-95°F)
• At night, usually shelter in hollow logs, ground debris, etc. (Cogger 2014)
  • May be active on warm nights (Swanson 1976; Hobden 2001; Cronin 2014)
  • Often seen on surfaces that retain heat (e.g., asphalt roads) (Horner 2004)

Home range

• Use multiple core areas that shift over time (Price-Rees, Brown, et al. 2013; Price-Rees, Brown, et al. 2014)
  • Size of home range varies little
  • Disperse to new locations often
  • May return to same shelter sites within a home range (Christian et al. 2003)
• Small core areas used by multiple individuals (Price-Rees, Brown, et al. 2013)
  • Core areas of females overlap
• Differences in use of suburban habitats (Koenig et al. 2001)
  • Some prefer garden habitat to natural forest habitat
  • Show strong site fidelity
    • Remain near shelter sites (especially pregnant females)
    • Males tend to move farther distances than females
• Home range size
  • Non-suburban habitats (Price-Rees, Brown, et al. 2013)
    • Average: 40,000 m² (400,000 ft²)
    • Range: 20,000-110,000 m² (200,000-1,200,000 ft²)
  • Suburban habitats (Koenig et al. 2001)
    • Males: 12,700 m² (137,000 ft²)
    • Females: 5,100 m² (55,000 ft²)
    • Pregnant females: 1,000 m² (10,000 ft²)

Dispersal

• Tend to disperse in morning or evening hours during hot, clear weather conditions (Price-Rees, Lindström, et al. 2014)
  • Avoid dispersing during hottest daytime hours
• Most movements less than 20 m (66 ft) (Price-Rees, Brown, et al. 2014)
  • Move long distance infrequently (Price-Rees, Brown, et al. 2013)
• Disperse about once per day (Price-Rees, Lindström, et al. 2014)
  • Rarely more than four times per day
• Daily movements
  • Price-Rees, Brown, et al. (2014) report daily movement distances of about 122-245 m (200-804 ft) per day [method: GPS tracking]
  • Christian et al. (2003) report daily movement distances of 97 m (318 ft; wet season) and 16 m (52 ft; dry season) [method: radio telemetry (less accurate than GPS)]

Adaptive behaviors in suburban areas

• Use corridors of dense vegetation (Koenig et al. 2001)
  • Avoid crossing roads
• Use human-made sheltered sites (e.g., drain pipes, sheds) (Koenig et al. 2001)

Group organization

• Unknown (Price-Rees, Brown, et al. 2013)

Smell and scent marking

• Possibly use chemical signals for communication (e.g., scent marking of territory) (Graves and Halpern 1991)
  • Members of Scincidae use chemical signals in various social and feeding behaviors (e.g., Cooper 1994; Main and Bull 1996)

Visual communication

• Protrude blue tongue during defense display (Abramjan et al. 2015)
  • See “Head and Mouth” (in General Appearance, Physical Characteristics)

Passive defense

• Freeze position (Mancera et al. 2017)
  • Body is tense and immobile
• Avoid stressful stimuli (Mancera et al. 2017)

Active defense

• Usually retreat when they perceive danger (Swanson 1976; Cronin 2014)
• If approached closely or cornered, exhibit warning display (Carpenter and Murphy 1978; Horner 2004; Abramjan et al. 2015)
  • Inflate or flatten body, arch body
    • Body appears larger to potential aggressor
  • Hiss
  • Open mouth to protrude flat, blue tongue
    • See “Head and Mouth” (in General Appearance, Physical Characteristics)
• Bite only as a “last resort”
  • Powerful jaws (Wilson 2012)
  • Wound to a human hand is painful but superficial (Swanson 1976)
    • Non-venomous
• Like other Tiliqua, able to detach tail to escape from predators (Horner 2004; Cogger 2014)

Aggression

• Show aggression towards predators (Abramjan et al. 2015)
• Reports of aggression towards conspecifics mainly from managed care settings (Amey et al. 2005)
• With acclimation, become docile in their interactions with humans (Horner 2004)

Regulation of body temperature

• Seek warm microhabitats during cool weather (Dutson and Dutson 2016)
• Acquire heat from warm surfaces they crawl on (Bartholomew et al. 1965)
  • Body usually in contact with ground

Burrowing

• Shelter in abandoned burrows, under fallen logs, and in crevices (Cronin 2014)
  • Dig burrows beneath hard surfaces (e.g., stone “roof” for protection) (Turner 2014)
• Curl up, with tail near head (Turner 2014)
• Uses of burrows
  • Overwintering (Turner 2014)
  • Conserve energy during dry season (Christian et al. 2003)

Other lizards

• Observed in close proximity to Tiliqua nigrolutea in some areas (Dutson and Dutson 2016)
  • T. scincoides and T. nigrolutea use slightly different microhabitats

Burrow usage

• Occupy burrows made by small mammals (Turner 2014) and other animals (e.g. goannas) (Samantha Price-Rees, personal communication, 2018)
• Eastern brown snake (Pseudonaja textilis) uses burrows made by T. scincoides (Turner 2014)

Relationship with humans

• Eastern blue-tongued skinks generally shy (Cronin 2014)
• May avoid areas used by high numbers of humans and domestic dogs (Dutson and Dutson 2016)
• Skink injury and mortality
  • In New South Wales, Shine and Koenig (2001) report over 8,900 T. scincoides “rescues” over a 10-year period
    • In Sydney, Koenig et al (2002) report 2,000 “rescues” over a 3-year period
  • Rescues more common during spring and summer, during active times of mating and giving birth (Koenig et al. 2002)
    • Adult males and newborns at higher risk, compared to females
• Used extensively in scientific studies of physiology, biochemistry, immunology, pathology, etc. (Shea 2004b)

Walking and running

• Relatively slow moving, except while retreating (Swanson 1976; Phillips 1986a; Cronin 2014, except as noted)
  • Heavily-bodied with short limbs
  • If threatened, tend to adopt defensive display as opposed to retreating quickly (Samantha Price-Rees, personal communication, 2018)
• Body usually in contact with ground (Bartholomew et al. 1965)
• In dense vegetation, tends to drag hind legs behind (Cronin 2014)
  • Sometimes mistaken for death adder snakes, Acanthophis spp.

Climbing

• Able to climb over obstacles (e.g., piles of rocks) (Horner 2004)

Swimming

• If required, effective swimmers (Samantha Price-Rees, personal communication, 2018)

A wild eastern blue-tongued skink sunning on concrete in a suburban yard.

This is one of the few large Australian lizards that adapts well to suburban areas and cities. This skink use hard surfaces, such as roads and drain pipes, for sun basking and shelter.

Image credit: © Kazredracer via Flickr. Creative Commons License BY-NC-ND 2.0. Some rights reserved.