Vipera berusLinnaeus, 1758

Adder

Photograph by xulescu_g, CC BY-SA, via iNaturalist

A ground-dwelling, day-active, meat-eating snake from the Palearctic region, reaching 935 mm nose to tail.

Also called Nikolsky's Viper, Northern Viper.

Once published as Pelias sachalinensis — those names reach this page.

Reptilia › Squamata › Viperidae › Vipera

Grows to: 935mm; greatest recorded
Eats: Carnivorous
Active: Diurnal
Lives up to: 30years

Body length across Viperidae

Longer than 59% of all vipers anyone has measured.

59% of 362 species are smaller41% larger

280 mmthe whole family, smallest to largest3,900 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 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

46 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
Population trend: Decreasing

The animal itself

Limbs: None
Colour on the back: Gray
Venomous: Yes
Fangs: At the front of the mouth
Longest recorded life: 30years
Body temp in the wild · mean, when active: 32°C

Size

Length snout to vent · greatest recorded: 833mm2 ft 9 in
Length snout to vent · adult female mean: 498.3mm19.5 in
Length nose to tail · greatest recorded: 935mm3 ft 1 in
Hatchling length · nose to tail: 170mm6.75 in
Body mass · greatestcomputed: 388.4g13.7 oz
Body mass · a typical adult: 279g9.8 oz
Body mass · adult female, meanmeasured: 70.2g2.5 oz
Body mass at hatchingmeasured: 3.27g0.12 oz

How it lives

Diet: Carnivorous
How it hunts: Sit and wait
Active: Diurnal
Where it lives: Terrestrial
Habitat: Forest
Biome: Boreal Forests/Taiga
Active season · months of the year: 6months
Region: Palearctic
Mainland or island: Mainland
Highest it lives · above sea level: 3000m
Range size: 13,331,502km²
Density: 0.6per hectare
Home range · largest recorded: 17,600m2

Breeding

Reproduction: Viviparous
Sex decided by: Genes, ZW/ZZ
Average clutch: 8.8eggs
Eggs or young per clutch: 2–20eggs
Mean clutch: 4.7–10.4eggs
Clutches in a year: 0.5per year
Clutches a year: 0.5per year
First breeds at: 24–48months

Naming and history

Suborder: Serpentes
Infraorder: Alethinophidia
Subspecies: Vipera berus barani BÖHME & JOGER 1983 Vipera berus berus (LINNAEUS 1758) Vipera berus bosniensis (BOETTGER 1889) Vipera berus marasso (POLLINI 1818) Vipera berus sachalinensis TZAREVSKY 1917
Described by: Linnaeus
Moved to another genus · since it was first described: Yes
Described in: 1758
Type locality: Sweden

Keeping one

3 ft 1 in × 18.5 in × 2 ft 4 in(94 × 47 × 70 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 3 ft 1 in (935 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 Adder. 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.

39kJ per day

Worked out for an animal of 388 g, the heaviest recorded for Adder — 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.

Morphs

2 with peer-reviewed genetics behind them, 0 resting on breeder consensus. Most references present both with the same confidence.

Melanoidpeer reviewed
- Comparative venom analysis between melanistic and normally coloured phenotypes of the common adder (Vipera berus). — R Soc Open Sci 2024
Skin colour (PMEL)peer reviewedPMEL
Casillas et al.: " V. berus  exhibits a range of dorsal color patterns spanning from zig-zag to complete melanism. However, a unique longitudinal dorsal stripe pattern was recently discovered in the isolated Gossa Island (∼45 km 2 ) population of Norway, where ∼5% of snakes
- Genome scanning reveals the genetic basis of a color pattern morphotype in an island population of the European adder (Vipera berus). — Genome Biol Evol 2026
- Dorsal stripe polymorphism of Vipera berus in south-east England — The Herpetological Bulletin 2020

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 · snout to vent
— Largest juvenile · snout to vent
— Largest juvenile · shell length
— Egg length
— Egg width
— 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
— 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
— Pattern on the back
— Pupil
— Red List criteria
— Active in
— Lowest it lives · above sea level

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). Vipera berus. Retrieved 2026-09-08, from https://www.allanglescreatures.com/species/vipera-berus

@misc{vipera_berus_2026,
  title  = {Vipera berus},
  author = {{The Reptile & Amphibian Encyclopedia}},
  year   = {2026},
  url    = {https://www.allanglescreatures.com/species/vipera-berus}
}

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.