Storeria occipitomaculataStorer, 1839

Redbelly Snake

Photograph by Clay Gibbons, CC BY, via iNaturalist

An active by day or night, meat-eating snake from the Nearctic region, reaching 410 mm nose to tail.

Also called Mexican Yellowbelly Brown Snake, Red-bellied Snake.

Reptilia › Squamata › Colubridae › Storeria

Grows to: 410mm; greatest recorded
Eats: Carnivorous
Active: Cathemeral
Lives up to: 4.6years

Body length across Colubridae

Longer than only 21% of all colubrid snakes anyone has measured.

21% of 2,008 species are smaller79% 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

38 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
Pupil: Round
Venomous: No
Fangs: At the back of the mouth
Longest recorded life: 4.6years
Body temperature when active · measured in the wild: 26.3°C79 °F
Body temp in the wild · mean, when active: 24.3–28.2°C76–83 °F

Size

Length snout to vent · greatest recorded: 230.5mm9 in
Length nose to tail · greatest recorded: 410mm16 in
Hatchling length · nose to tail: 75mm3 in
Body mass · greatestcomputed: 16.97g0.6 oz
Body mass at hatchingmeasured: 0.07g0 oz

How it lives

Diet: Carnivorous
Active: Cathemeral
Where it lives: Fossorial, terrestrial
Habitat: Forest, Shrubland, Wetlands
Biome: Temperate Broadleaf & Mixed Forests
Region: Nearctic
Mainland or island: Mainland
Highest it lives · above sea level: 1700m
Range size: 3,190,370km²

Breeding

Reproduction: Viviparous
Average clutch: 8.2eggs
Eggs or young per clutch: 1–25eggs
Mean clutch: 7–9eggs
Clutches in a year: 1per year
First breeds at: 24months

Naming and history

Suborder: Serpentes
Infraorder: Alethinophidia
Subspecies: Storeria occipitomaculata obscura TRAPIDO 1944 Storeria occipitomaculata occipitomaculata (STORER 1839) Storeria occipitomaculata pahasapae SMITH 1963
Described by: Storer
Moved to another genus · since it was first described: Yes
Described in: 1839
Type locality: USA

Keeping one

16 in × 8 in × 12 in(41 × 21 × 31 cm)

Minimum length × width × height, for one animal. Bigger is always better. Substrate at least 8 in (21 cm) deep.

The standard sizes snakes as a fraction of total length: 1 × 0.5 × 0.75.

Burrows, so substrate deep enough to dig in matters as much as floor area.

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 16 in (410 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 79 °F (26.3 °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.

2kJ per day

Worked out for an animal of 17 g, the heaviest recorded for Redbelly Snake — 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
— 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
— Eats arthropods
— Eats vertebrates
— Eats plant matter
— How it hunts
— How the young develop
— Gestation or incubation
— Clutches a year · fewest
— Clutches a year · most
— 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
— 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
— Lowest it lives · above sea level

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). Storeria occipitomaculata. Retrieved 2026-09-08, from https://www.allanglescreatures.com/species/storeria-occipitomaculata

@misc{storeria_occipitomaculata_2026,
  title  = {Storeria occipitomaculata},
  author = {{The Reptile & Amphibian Encyclopedia}},
  year   = {2026},
  url    = {https://www.allanglescreatures.com/species/storeria-occipitomaculata}
}

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.