Reptilia · Squamata
Gloydius halysPallas, 1776
Halys Pit Viper
Photograph by Dion Art, CC BY-SA, via Wikimedia Commons
A ground-dwelling, day-active, meat-eating snake from the Palearctic region, reaching 800 mm nose to tail.
Also called Pallas Pit Viper, Siberian Pitviper.
Reptilia › Squamata › Viperidae › Gloydius
- Grows to
- 800mm
- greatest recorded
- Eats
- Carnivorous
- Active
- Diurnal
- Lives up to
- 12.3years
Longer than only 43% of all vipers 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 280 to 3,900 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
36 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
- Yellow
- Venomous
- Yes
- Fangs
- At the front of the mouth
- Longest recorded life
- 12.3years
Stark et al. 2020
Size
- Length snout to vent · greatest recorded
- 690mm2 ft 3 in
- Length nose to tail · greatest recorded
- 800mm2 ft 7 in
- Hatchling length · snout to vent
- 175mm7 in
- Body mass · greatestcomputed
- 235.6g8.3 oz
- Body mass at hatchingmeasured
- 5.5g0.19 oz
750 mm total length (Feldman et al. 2016), 106.8 g (the Steinhardt Museum of Natural History), max 69 cm SVL, 11 cm tail, neonates 16-19 cm SVL, 5-6 g (Dunayev and Orlova 2023)
snakes only in this source
computed from length by a family-level allometric equation, not weighed
How it lives
- Diet
- Carnivorous
- How it hunts
- Sit and wait
- Active
- Diurnal
- Where it lives
- Terrestrial
- Habitat
- Forest, Grassland, Rocky, Shrubland
- Biome
- Deserts & Xeric Shrublands
- Active season · months of the year
- 6months
- Region
- Palearctic
- Mainland or island
- Mainland
- Elevation · above sea level
- 160–3000m
- Range size
- 2,793,045km²
- Density · highest recorded
- 267per hectare
- Home range · largest recorded
- 20,000m2
mainly mammals, birds and lizards (Dunayev and Orlova 2023)
Wang et al. 2023
(Simonov 2009: "Neonates of G. h. halys had two peaks of activity at 09.00-11.00 and 19.00-21.00. Adult snakes exhibit in front of their hidings after 11.00. Their activity reaches a plateau between 13.00-19.00. Around 21.00 adult of G. h. halys return to their night shelters."), diurnal, crepuuscular and nocturnal in summer (Dunayev and Orlova 2023, who say this for almost all reptiles...)
"surficial (terrestrial, non-scansorial)" (Gearty et al. 2021)
160-219 (Simonov 2009), max 3000 (Dunayev and Orlova 2023)
Breeding
- Reproduction
- Viviparous
- Average clutch
- 5eggs
- Eggs or young per clutch
- 3–14eggs
Feldman et al. 2015
3-10 (O'Shea 2011), 3-14 (Dunayev and Orlova 2023)
Naming and history
- Suborder
- Serpentes
- Infraorder
- Alethinophidia
- Subspecies
- Gloydius halys boehmei NILSON 1983 Gloydius halys halys (PALLAS 1776) Gloydius halys mogoi (BOUR 1993) Gloydius halys ubsunurensis KROPACHEV & ORLOV 2017
- Described by
- Pallas
- Moved to another genus · since it was first described
- Yes
- Described in
- 1776
- Type locality
- Russia
Keeping one
2 ft 7 in × 15.5 in × 23.5 in(80 × 40 × 60 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 7 in (800 mm), at 1 × 0.5 × 0.75 times it, following the German federal welfare standard — how this is worked out.
No preferred body temperature has been recorded for Halys Pit Viper. 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.
25kJ per day
Worked out for an animal of 236 g, the heaviest recorded for Halys Pit Viper — 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
- — 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
- — Egg length
- — Egg width
- — Body mass · a typical adult
- — 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
- — 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
- — Body temp in the wild · lowest mean recorded
- — Body temp in the wild · highest mean recorded
- — Pattern on the back
- — Pupil
- — Sex decided by
- — Population trend
- — Red List criteria
- — Density · lowest recorded
- — Active in
Others in Viperidae
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). Gloydius halys. Retrieved 2026-09-08, from https://www.allanglescreatures.com/species/gloydius-halys
@misc{gloydius_halys_2026,
title = {Gloydius halys},
author = {{The Reptile & Amphibian Encyclopedia}},
year = {2026},
url = {https://www.allanglescreatures.com/species/gloydius-halys}
}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.