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Squamata · ColubridaeEntry 9,029 of 21,572
Japanese Keelback, Hebius vibakari

Reptilia · Squamata

Hebius vibakariBoie, 1826

Japanese Keelback

Photograph by W.CC, CC BY-SA, via Wikimedia Commons

A ground-dwelling, dawn-and-dusk, meat-eating snake from the Palearctic region, reaching 650 mm nose to tail.

ReptiliaSquamataColubridaeHebius

Grows to
650mm
greatest recorded
Eats
Carnivorous
Active
Crepuscular
Lives
Terrestrial
Body length across Colubridae

Longer than only 48% of all colubrid snakes anyone has measured.

48% of 2,008 species are smaller52% 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

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
2016

The animal itself

Limbs
None
Colour on the back
Brown
Pupil
Round
Fangs
At the back of the mouth
Body temperature when active · measured in the wild
24.8°C77 °F

mean body temperature of active individuals in nature

Body temp in the wild · mean, when active
17.5–33°C64–91 °F

body temperature of active animals in nature

Size

Length nose to tail · greatest recorded
650mm2 ft 2 in

snakes only in this source

Hatchling length · snout to vent
155mm6 in

650 mm total length (Feldman et al. 2016), max SVL 40 mm, tail 11 cm, hatchling body length 15-16 cm (Dunayev and Orlova 2023), Wang et al. 2023 (female standard length [probably total length, unsure] 441~458 mm)

Body mass · greatestcomputed
67.29g2.4 oz

computed from length by a family-level allometric equation, not weighed

How it lives

Diet
Carnivorous

earthworms, frogs, tadpoles, and loaches (Park et al. 2022), molluscs, insects, frogs (Dunayev and Orlova 2023)

How it hunts
Active foraging

Wang et al. 2023

Active
Crepuscular

"Although diurnal, it prefers cooler temperatures and is active mainly in the early mornings and evenings (Goris and Maeda 2004) (recorded by Anuj Shinde), hides during the day (Dunayev and Orlova 2023)

Where it lives
Terrestrial

Deepak et al. 2022

Habitat
Forest, Grassland
Biome
Temperate Broadleaf & Mixed Forests
Region
Palearctic
Mainland or island
Mainland
Elevation · above sea level
60–90m

62-84 (Park et al. 2022)

Range size
1,229,460km²

Breeding

Reproduction
Oviparous

Feldman et al. 2015

Sex decided by
Genes, ZW/ZZ
Average clutch
3eggs
Eggs or young per clutch
2–6eggs

2-6 (Dunayev and Orlova 2023)

Egg length
29.1mm1.25 in
Egg width
11.7mm0.5 in

Naming and history

Suborder
Serpentes
Infraorder
Alethinophidia
Subspecies
Hebius vibakari danjoensis TORIBA 1986 Hebius vibakari vibakari (BOIE 1826) Hebius vibakari ruthveni (VAN DENBURGH 1923)
Described by
Boie
Moved to another genus · since it was first described
Yes
Described in
1826
Type locality
Japan

Keeping one

2 ft 2 in × 13 in × 19 in(65 × 33 × 49 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 × 0.75.

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 2 ft 2 in (650 mm), at 1 × 0.5 × 0.75 times it, following the German federal welfare standard — how this is worked out.

Active animals measured in the wild averaged 77 °F (24.8 °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 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.

8kJ per day

Worked out for an animal of 67 g, the heaviest recorded for Japanese Keelback — 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 · nose to tail
  • Largest juvenile · snout to vent
  • Largest juvenile · shell length
  • 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 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
  • Venomous
  • 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). Hebius vibakari. Retrieved 2026-09-08, from https://www.allanglescreatures.com/species/hebius-vibakari

@misc{hebius_vibakari_2026,
  title  = {Hebius vibakari},
  author = {{The Reptile & Amphibian Encyclopedia}},
  year   = {2026},
  url    = {https://www.allanglescreatures.com/species/hebius-vibakari}
}

Sources

  1. Meiri, S. (2024). SquamBase — a database of squamate (Reptilia: Squamata) traits. Global Ecology and Biogeography. Public domain (CC0).
  2. Oskyrko, O. et al. (2024). ReptTraits: a comprehensive dataset of ecological traits in reptiles. Scientific Data. Used under CC BY 4.0.
  3. Catalogue of Life (dataset 3LR), used under CC BY.