Reptilia · Squamata
Tribolonotus gracilisde Rooij, 1909
Red-eyed Crocodile Skink
Photograph by Piranhapirate, CC BY-SA, via Wikimedia Commons
A day-active, meat-eating skink from the Australo-Pacific region, reaching 103 mm snout to vent.
Also called Red-Eyed Bush Crocodile Skink.
Reptilia › Squamata › Scincidae › Tribolonotus
- Grows to
- 103mm
- greatest recorded
- Eats
- Carnivorous
- Active
- Diurnal
- Lives
- Fossorial, terrestrial
Longer than 79% of all skinks anyone has measured.
The bar is the rank itself: its length is the share of the family this animal exceeds. The chart below is the family’s real spread, on a logarithmic scale because body length here runs from 24 to 500 mm. The solid rule is this animal. Every bar is a count of real species, and nothing on this figure is estimated.
What is known
32 sourced facts, each taken from a named scientific dataset. How to read these.
Cited from a dataset unless a row is marked otherwise.
Standing in the world
- Still living
- Extant
- Conservation status
- Least Concern
- Status assessed · the year the Red List last looked
- 2014
The animal itself
- Limbs
- Four legs
- Venomous
- No
- Fangs
- None
- Body temperature when active · measured in the wild
- 24.6°C76 °F
- Body temp in the wild · mean, when active
- 24.6°C
mean body temperature of active individuals in nature
body temperature of active animals in nature
Size
- Length snout to vent · greatest recorded
- 103mm4 in
- Length snout to vent · adult female mean
- 93.5mm3.75 in
- Largest female · snout to vent
- 93.5mm3.75 in
- Body mass · greatestcomputed
- 23.34g0.82 oz
max 103 mm SVL (Feldman et al. 2016)
snout-vent length; the source column mixes this with straight carapace length
computed from length by a family-level allometric equation, not weighed
How it lives
- Diet
- Carnivorous
- Active
- Diurnal
- Where it lives
- Fossorial, terrestrial
- Habitat
- Forest
- Biome
- Tropical & Subtropical Moist Broadleaf Forests
- Region
- Australo-Pacific
- Mainland or island
- Found only on islands
- Elevation · above sea level
- 600m
- Range size
- 117,107km²
insects, in captivity (http://www.exotic-pets.co.uk/red-eyed-crocodile-skink.html)
Rodda 2020
Leaf Litter/fossorial and terrestrial (Fred Kraus, pers. comm. Janary 2019)
Breeding
- Reproduction
- Oviparous
- Sex decided by
- Genes, XX/XY
- Average clutch
- 1eggs
- Eggs or young per clutch
- 1eggs
Naming and history
- Suborder
- Sauria
- Infraorder
- Scincoidea
- Subspecies
- No
- Described by
- De Rooij
- Moved to another genus · since it was first described
- No
- Described in
- 1909
- Type locality
- Indonesia
Keeping one
16 in × 16 in × 10 in(41 × 41 × 26 cm)
Minimum length × width × height, for one animal. Bigger is always better. Substrate at least 2 in (5 cm) deep.
The standard sizes ground-dwelling species at 4 × 4 × 2.5 times snout-vent length.
Burrows, so substrate deep enough to dig in matters as much as floor area.
Mindestanforderungen an die Haltung von Reptilien (Sachverständigengutachten), German Federal Ministry for Nutrition, Agriculture and Forestry, Animal Welfare Division, 10 January 1997. The standard states these floor areas are recommendations rather than binding limits.
From this animal’s own snout-vent length of 4 in (103 mm), at 4 × 4 × 2.5 times it, following the German federal welfare standard — how this is worked out.
Active animals measured in the wild averaged 76 °F (24.6 °C).
Mean body temperature of active individuals measured in nature. A measurement of the animal, not a setting for a thermostat.
Feeding
A prey item should be no wider than the space between the animal's eyes.
Widely used across reptile husbandry references. The stated reason is that the gap approximates the width of the throat, so wider prey is associated with impaction. This is established practice, not a measurement.
3kJ per day
Worked out for an animal of 23 g, the heaviest recorded for Red-eyed Crocodile Skink — so it is the top of the range, not a figure for a particular animal. Weigh yours and the number will be lower.
An upper estimate, not a feeding target, and not veterinary advice. The equation covers only what an animal burns staying alive, so a growing, gravid or recovering animal needs more — and it was measured on wild animals, which move far more than one in an enclosure. Body condition and a vet who knows the species are what a feeding decision should rest on. Where this comes from.
Morphs
0 with peer-reviewed genetics behind them, 1 resting on breeder consensus. Most references present both with the same confidence.
- Natural variationbreeder consensus
How bright the orange eye-ring is and how dark the body. This varies between individuals and with condition, and no single-gene morph has been established in this species.
Worth knowing. Red-eyed crocodile skinks are still largely wild-caught and are bred in captivity in small numbers, so no morph scene has developed. Anything offered as a morph in this species is describing an individual animal rather than a gene it would pass on.
What nobody knows
These are not gaps in our research. No scientific dataset records them for this species — and saying so is information you cannot get from a reference that simply leaves a field out.
- — Length snout to vent · adult male mean
- — Length snout to vent · adult mean
- — Length nose to tail · greatest recorded
- — Female length · mean, nose to tail
- — Length nose to tail · adult male mean
- — Length nose to tail · adult mean
- — Largest male · snout to vent
- — Largest female · shell length
- — Largest male · shell length
- — Hatchling length · snout to vent
- — Hatchling length · nose to tail
- — Largest juvenile · snout to vent
- — Largest juvenile · shell length
- — Egg length
- — Egg width
- — Body mass · a typical adult
- — Body mass · adult female, mean
- — Body mass at hatching
- — Longest recorded life
- — Preferred body temperature · chosen in a laboratory gradient
- — Eats arthropods
- — Eats vertebrates
- — Eats plant matter
- — How it hunts
- — How the young develop
- — Gestation or incubation
- — Mean clutch · smallest reported
- — Mean clutch · largest reported
- — Clutches in a year
- — Clutches a year · fewest
- — Clutches a year · most
- — First breeds from · youngest recorded
- — First breeds by · oldest recorded
- — Hatchling length · smallest recorded
- — Hatchling length · largest recorded
- — Age at first breeding · female
- — Mature from · youngest recorded
- — Mature by · oldest recorded
- — Size at maturity · smallest recorded
- — Size at maturity · largest recorded
- — Colour on the back
- — Pattern on the back
- — Pupil
- — Population trend
- — Red List criteria
- — Active season · shortest recorded
- — Active season · longest recorded
- — Density · lowest recorded
- — Density · highest recorded
- — Home range · largest recorded
- — Active in
Others in Scincidae
Take this data
Everything on this page is available as data under CC BY 4.0 — use it freely, credit it, no permission needed.
This species as JSON · the whole dataset
Cite this page
The Reptile & Amphibian Encyclopedia (2026). Tribolonotus gracilis. Retrieved 2026-09-08, from https://www.allanglescreatures.com/species/tribolonotus-gracilis
@misc{tribolonotus_gracilis_2026,
title = {Tribolonotus gracilis},
author = {{The Reptile & Amphibian Encyclopedia}},
year = {2026},
url = {https://www.allanglescreatures.com/species/tribolonotus-gracilis}
}Sources
- Meiri, S. (2024). SquamBase — a database of squamate (Reptilia: Squamata) traits. Global Ecology and Biogeography. Public domain (CC0).
- Oskyrko, O. et al. (2024). ReptTraits: a comprehensive dataset of ecological traits in reptiles. Scientific Data. Used under CC BY 4.0.
- Catalogue of Life (dataset 3LR), used under CC BY.