Reptilia · Squamata
Boiga irregularisBechstein, 1802
Brown catsnake
Photograph placed in the public domain, CC0, via iNaturalist
A tree-dwelling, nocturnal, meat-eating snake from the Australo-Pacific region, reaching 220 cm nose to tail.
Also called Brown Tree Snake.
Reptilia › Squamata › Colubridae › Boiga
- Grows to
- 2200mm
- greatest recorded
- Eats
- Carnivorous
- Active
- Nocturnal
- Lives up to
- 19years
Longer than 97% 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
40 sourced facts, each taken from a named scientific dataset. How to read these.
Cited from a dataset unless a row is marked otherwise.
Two of these figures disagree
Body mass (a typical adult) is given as 4,748, and Body mass (greatest) as 334 — but a typical adult cannot outweigh the heaviest one ever recorded. They come from different sources and both are shown exactly as those sources give them.
Standing in the world
- Still living
- Extant
- Conservation status
- Least Concern
- Status assessed · the year the Red List last looked
- 2017
- Population trend
- Stable
The animal itself
- Limbs
- None
- Colour on the back
- Black, Brown
- Pattern on the back
- Banded, blotched
- Venomous
- Yes
- Longest recorded life
- 19years
Stark et al. 2020
Size
- Length snout to vent · greatest recorded
- 1225mm4 ft
- Length snout to vent · adult female mean
- 952mm3 ft 1 in
- Length nose to tail · greatest recorded
- 2200mm7 ft 3 in
- Hatchling length · snout to vent
- 296mm11.5 in
- Body mass at hatchingmeasured
- 9.3g0.33 oz
- Body mass · greatestcomputeddisputed
- 334g11.8 oz
- Body mass · a typical adultdisputed
- 4748g10 lb
2200 mm total length (Feldman et al. 2016), Lettoof et al. 2023(SVL 1002 mm, mass 149 g), Shine 1994 (125 males 62.4-163 .0, mean 101.7 cm SVL; 81 females 63.7-122.5, mean 95.2 cm SVL; hatchling SVL 296 mm, see also Shine 1991)
snakes only in this source
computed from length by a family-level allometric equation, not weighed
AnAge rates this record "acceptable"
How it lives
- Diet
- Carnivorous
- How it hunts
- Mixed
- Active
- Nocturnal
- Where it lives
- Arboreal
- Habitat
- Forest, Rocky, Shrubland
- Biome
- Tropical & Subtropical Grasslands, Savannas & Shrublands
- Region
- Australo-Pacific
- Mainland or island
- Mainland
- Highest it lives · above sea level
- 2290m
- Range size
- 2,436,265km²
reptiles and birds (Lettoof et al. 2023), reptiles, birds, mammals, few amphibians (Shine 1991)
Glaudas et al. 2019
(Stark et al. 2018, Cogger 2018, Murphy et al. 2003, Lettoof et al. 2023, Sires 2021), crepuscular and nocturnal (Shine 1991)
Scharf et al. 2015, Cogger 2018, Murphy et al. 2003, Lettoof et al. 2023
0-2286 (O'Shea 2018)
Breeding
- Reproduction
- Oviparous
- Gestation or incubation
- 77days
- Average clutch
- 5.5eggs
- Eggs or young per clutch
- 2–12eggs
- Mean clutch
- 5.5eggs
- Egg length
- 42mm1.75 in
- Egg width
- 17.9mm0.7 in
Feldman et al. 2015, Meiri et al. 2019
3-11 mean=5.5 s.d.=2.2 n=21 (Shine 1991 see also Lettoof et al. 2023), 3-11 (O'Shea 2011), max=12 (Cogger 2018, Murphy et al. 2003), 2-11 (O'Shea 2018), Shine 1994 (3-11, mean 5.5, n = 21 clutches)
Naming and history
- Suborder
- Serpentes
- Infraorder
- Alethinophidia
- Subspecies
- No
- Described by
- Bechstein
- Moved to another genus · since it was first described
- Yes
- Described in
- 1802
- Type locality
- Unknown
Keeping one
5 ft 5 in × 3 ft 7 in × 10 ft 10 in(165 × 110 × 330 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 7 ft 3 in (2200 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 Brown catsnake. 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.
34kJ per day
Worked out for an animal of 334 g, the heaviest recorded for Brown catsnake — 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 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 · nose to tail
- — Largest juvenile · snout to vent
- — Largest juvenile · shell length
- — Body mass · adult female, mean
- — 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
- — 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
- — Fangs
- — Body temp in the wild · lowest mean recorded
- — Body temp in the wild · highest mean recorded
- — Pupil
- — Sex decided by
- — Red List criteria
- — Active season · shortest recorded
- — Active season · longest recorded
- — Density · lowest recorded
- — Density · highest recorded
- — Home range · largest recorded
- — Active in
- — Lowest it lives · above sea level
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). Boiga irregularis. Retrieved 2026-09-08, from https://www.allanglescreatures.com/species/boiga-irregularis
@misc{boiga_irregularis_2026,
title = {Boiga irregularis},
author = {{The Reptile & Amphibian Encyclopedia}},
year = {2026},
url = {https://www.allanglescreatures.com/species/boiga-irregularis}
}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.
- AnAge, Human Ageing Genomic Resources (de Magalhães et al.), used under CC BY 3.0.