Reptilia · Squamata
Crotalus oreganusHolbrook, 1840
Northern Pacific Rattlesnake
Photograph by Guillermo Roque, CC BY, via iNaturalist
A nocturnal, meat-eating snake from the Nearctic region, reaching 163 cm nose to tail.
Also called Grand Canyon Rattlesnake.
Reptilia › Squamata › Viperidae › Crotalus
- Grows to
- 1625mm
- greatest recorded
- Eats
- Carnivorous
- Active
- Nocturnal
- Lives up to
- 31years
Longer than 90% 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
- 2007
- Population trend
- Stable
The animal itself
- Limbs
- None
- Venomous
- Yes
- Fangs
- At the front of the mouth
- Longest recorded life
- 31years
- Preferred body temperature · chosen in a laboratory gradientmeasured
- 28°C
- Body temperature when active · measured in the wild
- 15.55°C60 °F
- Body temp in the wild · mean, when active
- 17.5–34.5°C64–94 °F
mean body temperature of active individuals in nature
body temperature of active animals in nature
Size
- Length snout to vent · greatest recorded
- 920mm3 ft
- Length nose to tail · greatest recorded
- 1625mm5 ft 4 in
- Body mass · greatestcomputed
- 2140.8g4.7 lb
snakes only in this source
computed from length by a family-level allometric equation, not weighed
How it lives
- Dietcomputed
- Carnivorous
- How it hunts
- Mixed
- Active
- Nocturnal
- Where it lives
- Arboreal, terrestrial
- Habitat
- Forest, Grassland, Rocky, Savanna, Shrubland
- Biome
- Deserts & Xeric Shrublands
- Region
- Nearctic
- Mainland or island
- Mainland
- Elevation · above sea level
- 56–3269m
- Range size
- 1,432,994km²
no actual data but can be imputed as carnivorous like all snakes
(Feldman 2015), Sit and wait (Maag and Clark 2022)
Scharf et al. 2015
Arboreal&Terrestrial (Feldman 2015)
Breeding
- Reproduction
- Viviparous
- Average clutch
- 9.8eggs
- Eggs or young per clutch
- 9–10eggs
- Mean clutch
- 9.8eggs
- Clutches in a year
- 0.42per year
Feldman et al. 2015
mean 9.8 (Scharf et al. 2015)
Naming and history
- Suborder
- Serpentes
- Infraorder
- Alethinophidia
- Subspecies
- No
- Described by
- Holbrook
- Moved to another genus · since it was first described
- No
- Described in
- 1840
- Type locality
- USA
Keeping one
5 ft 4 in × 2 ft 8 in × 8 ft(163 × 81 × 244 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 × 1.5.
Recorded both on the ground and climbing, so this is the larger of the two rules in every dimension.
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 5 ft 4 in (1625 mm), at 1 × 0.5 × 1.5 times it, following the German federal welfare standard — how this is worked out.
In a laboratory thermal gradient this species settled at 82 °F (28 °C).
Preferred body temperature, recorded in a laboratory gradient where the animal could choose freely. 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.
179kJ per day
Worked out for an animal of 2,141 g, the heaviest recorded for Northern Pacific Rattlesnake — 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 · snout to vent
- — 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
- — Body mass at hatching
- — Eats arthropods
- — Eats vertebrates
- — Eats plant matter
- — How the young develop
- — Gestation or incubation
- — 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
- — Colour on the back
- — Pattern on the back
- — 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
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). Crotalus oreganus. Retrieved 2026-09-08, from https://www.allanglescreatures.com/species/crotalus-oreganus
@misc{crotalus_oreganus_2026,
title = {Crotalus oreganus},
author = {{The Reptile & Amphibian Encyclopedia}},
year = {2026},
url = {https://www.allanglescreatures.com/species/crotalus-oreganus}
}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.