Reptilia · Squamata
Crotalus ruberCope, 1892
Red Rattlesnake
Photograph by Amy Huie, CC BY, via iNaturalist
An active by day or night, meat-eating snake from the Nearctic region, reaching 165 cm nose to tail.
Also called Red Diamond Rattlesnake, red diamond rattlesnake.
Reptilia › Squamata › Viperidae › Crotalus
- Grows to
- 1650mm
- greatest recorded
- Eats
- Carnivorous
- Active
- Cathemeral
- Lives up to
- 19.2years
Longer than 91% 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.
Two of these figures disagree
Body mass (a typical adult) is given as 3,661, and Body mass (greatest) as 2,238.1 — 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
- 2007
- Population trend
- Decreasing
The animal itself
- Limbs
- None
- Venomous
- Yes
- Fangs
- At the front of the mouth
- Longest recorded life
- 19.2years
- Body temperature when active · measured in the wild
- 22.72°C73 °F
- Body temp in the wild · mean, when active
- 17.5–34.5°C64–94 °F
Stark et al. 2020
mean body temperature of active individuals in nature
body temperature of active animals in nature
Size
- Length nose to tail · greatest recorded
- 1650mm5 ft 5 in
- Body mass at hatchingmeasured
- 17.4g0.61 oz
- Body mass · greatestcomputeddisputed
- 2238.1g4.9 lb
- Body mass · a typical adultdisputed
- 3661g8.1 lb
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
- Cathemeral
- Where it lives
- Arboreal, terrestrial
- Habitat
- Desert, Forest, Grassland, Rocky, Shrubland
- Biome
- Deserts & Xeric Shrublands
- Region
- Nearctic
- Mainland or island
- Mainland
- Highest it lives · above sea level
- 1500m
- Range size
- 158,095km²
rodents (Grismer and Grismer 2022)
(Feldman 2015), Sit and wait (Maag and Clark 2022)
(Hu et al. 2020), "active at daytime during the cooler months, but become more active at night with the onset of high summer temperatures" (Grismer and Grismer 2022)
Arboreal&Terrestrial (Feldman 2015)
0-1500 (Feldman 2015)
Breeding
- Reproduction
- Viviparous
- Sex decided by
- Genes, ZW/ZZ
- Average clutch
- 8eggs
- Eggs or young per clutch
- 8–20eggs
- Mean clutch
- 8eggs
Feldman et al. 2015, Meiri et al. 2019
mean 8 (Meiri et al. 2019), up to 20 (Grismer and Grismer 2022)
Naming and history
- Suborder
- Serpentes
- Infraorder
- Alethinophidia
- Subspecies
- Crotalus ruber exsul GARMAN 1884 Crotalus ruber ruber COPE 1892 Crotalus ruber lucasensis VAN DENBURGH 1920
- Described by
- Cope
- Moved to another genus · since it was first described
- No
- Described in
- 1892
- Type locality
- USA
Keeping one
5 ft 5 in × 2 ft 8 in × 8 ft 1 in(165 × 83 × 248 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 5 in (1650 mm), at 1 × 0.5 × 1.5 times it, following the German federal welfare standard — how this is worked out.
Active animals measured in the wild averaged 73 °F (22.7 °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.
186kJ per day
Worked out for an animal of 2,238 g, the heaviest recorded for Red 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 · 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 · snout to vent
- — Hatchling length · nose to tail
- — Largest juvenile · snout to vent
- — Largest juvenile · shell length
- — Egg length
- — Egg width
- — Body mass · adult female, mean
- — Preferred body temperature · chosen in a laboratory gradient
- — Eats arthropods
- — Eats vertebrates
- — Eats plant matter
- — How the young develop
- — Gestation or incubation
- — 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
- — Colour on the back
- — Pattern on the back
- — Pupil
- — 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 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 ruber. Retrieved 2026-09-08, from https://www.allanglescreatures.com/species/crotalus-ruber
@misc{crotalus_ruber_2026,
title = {Crotalus ruber},
author = {{The Reptile & Amphibian Encyclopedia}},
year = {2026},
url = {https://www.allanglescreatures.com/species/crotalus-ruber}
}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.