Reptilia · Squamata
Coelognathus radiatusBoie, 1827
Radiated Ratsnakes
Photograph by Ioannis Magouras, CC BY, via iNaturalist
A day-active, meat-eating snake from the Oriental region, reaching 262 cm nose to tail.
Also called Copper-headed Trinket Snake, Copperhead Rat Snake.
Reptilia › Squamata › Colubridae › Coelognathus
- Grows to
- 2620mm
- greatest recorded
- Eats
- Carnivorous
- Active
- Diurnal
- Lives
- Arboreal, terrestrial
Longer than 99% of all colubrid snakes 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 98 to 3,800 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
35 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
- 2011
The animal itself
- Limbs
- None
- Colour on the back
- Brown, Gray
- Pupil
- Round
- Fangs
- At the back of the mouth
Size
- Length nose to tail · greatest recorded
- 2620mm8 ft 7 in
- Hatchling length · nose to tail
- 295mm11.5 in
- Body mass · greatestcomputed
- 1153.1g2.5 lb
- Body mass at hatchingmeasured
- 11.7g0.41 oz
snakes only in this source
computed from length by a family-level allometric equation, not weighed
How it lives
- Diet
- Carnivorous
- How it hunts
- Active foraging
- Active
- Diurnal
- Where it lives
- Arboreal, terrestrial
- Habitat
- Forest, Grassland, Savanna
- Biome
- Tropical & Subtropical Moist Broadleaf Forests
- Region
- Oriental
- Mainland or island
- Mainland
- Elevation · above sea level
- 20–1520m
- Range size
- 6,668,486km²
rodents and birds, also frogs, juveniles eat lizards (Messenger 2021), small mammals, birds and lizards (Mohapatra et al. 2021) to which Cox et al. 2012add frogs
Wang et al. 2023
(Feldman 2015, Cox et al. 2012), Javed et al. 2010b: "According to Günther (1864) it is equally diurnal and nocturnal", their specimen was active midday, primarily diurnal (Messenger 2021), crepuscular (Mohapatra et al. 2021), afternoon (Pham et al. 2022, n = 1)
Arboreal&Terrestrial (Feldman 2015)/terrestrial but also excellent climber and swimmer (Messenger 2021), terrestrial (Mohapatra et al. 2021, see also Pham et al. 2022, Javed et al. 2010b), terrestrial but a good climber (Cox et al. 2012)
50-1500 (Feldman 2015), 20-1515 (Das 2013), max 1480 (Cox et al. 2012)
Breeding
- Reproduction
- Oviparous
- Sex decided by
- Genes, ZW/ZZ
- Average clutch
- 7.5eggs
- Eggs or young per clutch
- 5–15eggs
- Egg length
- 59mm2.25 in
- Egg width
- 28mm1 in
- First breeds at
- 24–36months
Feldman et al. 2015
5-15 (Whitaker and Captain 2004, Cox et al. 2012), 6-13 (Messenger 2021), 5-12 (Das 2013), max 14 (Mohapatra et al. 2021)
Naming and history
- Suborder
- Serpentes
- Infraorder
- Alethinophidia
- Subspecies
- No
- Described by
- Boie
- Moved to another genus · since it was first described
- Yes
- Described in
- 1827
- Type locality
- Indonesia
Keeping one
8 ft 7 in × 4 ft 4 in × 12 ft 11 in(262 × 131 × 393 cm)
Minimum length × width × height, for one animal. Bigger is always better.
The standard sizes snakes as a fraction of total length: 1 × 0.5 × 1.5.
Recorded both on the ground and climbing, so this is the larger of the two rules in every dimension.
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 total length of 8 ft 7 in (2620 mm), at 1 × 0.5 × 1.5 times it, following the German federal welfare standard — how this is worked out.
No preferred body temperature has been recorded for Radiated Ratsnakes. Rather than repeat a number from a care sheet, this page leaves it out.
Feeding
A prey item should be between the same width as the widest part of the snake's body and about 1.5 times that width.
Widely used across snake husbandry references. An alternative formulation gives prey at 10-15% of the snake's body mass. This is established practice, not a measurement.
103kJ per day
Worked out for an animal of 1,153 g, the heaviest recorded for Radiated Ratsnakes — 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.
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 · greatest recorded
- — Length snout to vent · adult female mean
- — Length snout to vent · adult male mean
- — Length snout to vent · adult mean
- — Female length · mean, nose to tail
- — Length nose to tail · adult male mean
- — Length nose to tail · adult mean
- — Largest female · snout to vent
- — Largest male · snout to vent
- — Largest female · shell length
- — Largest male · shell length
- — Hatchling length · snout to vent
- — Largest juvenile · snout to vent
- — Largest juvenile · shell length
- — Body mass · a typical adult
- — Body mass · adult female, mean
- — Longest recorded life
- — Preferred body temperature · chosen in a laboratory gradient
- — Body temperature when active · measured in the wild
- — Eats arthropods
- — Eats vertebrates
- — Eats plant matter
- — 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
- — 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
- — Venomous
- — Body temp in the wild · lowest mean recorded
- — Body temp in the wild · highest mean recorded
- — Pattern on the back
- — 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 Colubridae
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). Coelognathus radiatus. Retrieved 2026-09-08, from https://www.allanglescreatures.com/species/coelognathus-radiatus
@misc{coelognathus_radiatus_2026,
title = {Coelognathus radiatus},
author = {{The Reptile & Amphibian Encyclopedia}},
year = {2026},
url = {https://www.allanglescreatures.com/species/coelognathus-radiatus}
}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.