Gonyosoma boulengeriMocquard, 1897

Rhino Rat Snake

Photograph by derivative work: TimVickers (talk)…, Public domain, via Wikimedia Commons

A tree-dwelling, day-active, meat-eating snake from the Oriental region, reaching 138 cm nose to tail.

Also called Rhinoceros Snake.

Reptilia › Squamata › Colubridae › Gonyosoma

Grows to: 1380mm; greatest recorded
Eats: Carnivorous
Active: Diurnal
Lives up to: 20years

Body length across Colubridae

Longer than 85% of all colubrid snakes anyone has measured.

85% of 2,008 species are smaller15% larger

98 mmthe whole family, smallest to largest3,800 mm

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

37 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: Green
Pattern on the back: Uniform
Pupil: Round
Fangs: At the back of the mouth
Longest recorded life: 20years

Size

Length snout to vent · greatest recorded: 1033mm3 ft 5 in
Length nose to tail · greatest recorded: 1380mm4 ft 6 in
Female length · mean, nose to tail: 1195.3mm3 ft 11 in
Hatchling length · nose to tail: 220mm8.75 in
Body mass · greatestcomputed: 222.1g7.8 oz

How it lives

Diet: Carnivorous
How it hunts: Active foraging
Active: Diurnal
Where it lives: Arboreal
Habitat: Forest
Biome: Tropical & Subtropical Moist Broadleaf Forests
Active season · months of the year: 8–9months
Region: Oriental
Mainland or island: Mainland
Elevation · above sea level: 200–1500m
Range size: 77,174km²

Breeding

Reproduction: Oviparous
Average clutch: 7.5eggs
Eggs or young per clutch: 6–15eggs
Clutches a year: 1–2per year
First breeds at: 36–48months

Naming and history

Suborder: Serpentes
Infraorder: Alethinophidia
Subspecies: No
Described by: Mocquard
Moved to another genus · since it was first described: Yes
Described in: 1897
Type locality: Norway

Keeping one

3 ft 5 in × 2 ft 3 in × 6 ft 9 in(104 × 69 × 207 cm)

Minimum length × width × height, for one animal. Bigger is always better.

The standard sizes snakes as a fraction of total length: 0.75 × 0.5 × 1.5.

Lives in vegetation, so height and climbing structure matter more than floor space.

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 4 ft 6 in (1380 mm), at 0.75 × 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 Rhino Rat Snake. 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.

24kJ per day

Worked out for an animal of 222 g, the heaviest recorded for Rhino Rat Snake — 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 · adult female mean
— Length snout to vent · adult male mean
— Length snout to vent · adult mean
— 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
— Egg length
— Egg width
— Body mass · a typical adult
— Body mass · adult female, mean
— Body mass at hatching
— 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
— 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
— Sex decided by
— Population trend
— Red List criteria
— 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). Gonyosoma boulengeri. Retrieved 2026-09-08, from https://www.allanglescreatures.com/species/gonyosoma-boulengeri

@misc{gonyosoma_boulengeri_2026,
  title  = {Gonyosoma boulengeri},
  author = {{The Reptile & Amphibian Encyclopedia}},
  year   = {2026},
  url    = {https://www.allanglescreatures.com/species/gonyosoma-boulengeri}
}

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.